I agree that Maxxairs are incredibly unreliable in the environment in which they're intended. I refuse to use Maxxair in my builds BECAUSE the one I had fried *three* motherboards on a *regulated* DC circuit @13.2vdc. I was an electronic technician for years, and whoever designed that should be fired. I use Fantastic, instead. No problems. Just as quiet. Agree about the conformal coating - again - in a VERY humid environment, it's criminal to not be properly protected with conformal coating. You can fix them, I suppose, but these two things, so BASIC in the use of these fans makes me doubt any other part of the design.
Former NASA engineer concurs w findings! Great diagnosis and fix on this! I'm on Spotify, YT Applemusic and touring a town near you w my broken maxxair fan😂.
George: Loved visiting the new Research and Development Laboratory. Of course, after years of watching Humble Road episodes, I was already familiar with the Mad Scientist that runs the place.😵💫🤔🥰
My van came last week, today is Day 1 of my build and after a year of watching you, George, I've decided to take her on myself! I've watched the floor videos more times than I can count!
GEORGE: LOVED the video and seeing my favorite "our gang" show ❤💪. Your wit, ingenuity and taste is impeccable... Father Healy or Shaw taught you well....😊
Thanks George. I have the fan with the remote. Had trouble with it years ago but connecting for a while and disconnecting the power solved it. Now go forward 6 years. Just went other day to connect the power and the board blew. Puff. Done. Fortunately when I had the trouble the first time I called them under warranty and they sent a new board which I still have in the box. So I just ordered the small transformer and that spray. Once they come I’ll be dismantling my unit and swapping the board within your new design. Hopefully that will solve it. It is so strange that they would have this problem. I never noticed the voltage limitation when I installed. 13.6. That’s no where near enough. My agm battery needs 14.6 to charge. Clearly they must assume rv voltages never exceed 13.6 which just isn’t the case. Even an a vehicular situation it is not unusual to have 14.1 volts in the electrical system when alternator is wide open charging. Someone clearly wasn’t thinking. Probably the new board they sent me is fine. But I’m with you. Belt and suspenders. Fool me once shame on you. Fool me twice shame on me. I’ll regulate the voltage for the fan. Thanks again. I was going to do this research myself. Thanks for solving it for me.
Its so great you did a video on this. I almost purchased that model until I saw this issue in a number of reviews. Such a simple oversight on their part. Glad they are fixing it. I went with an older version fan (with the manual knob).
I just recieved my replacement board after making a warranty claim 6 months ago...I'll be sealing the PCB with CRC Urathane Seal Coat and installing the voltage regulator you recommend. Thanks for the video!
I had a conversation with Maxxair today about my failed motherboards (I have one fan that had the MB fail twice on it, and I have it on regulated power). They are sending me a new fan because they told me that the MB failure is likely due to a MOTOR problem, not the voltage problem that most people blame it on. He said they had a brushed motor in there that would accumulate the carbon from the brushes and then it will essentially draw too much power through the MB, eventually leading to the MB failing. Essentially it was a design flaw in the motor that has since been corrected. So not all issues are due to overvoltage! That is the first lesson. They believe that the V3 boards (which started shipping out starting in early 2022) resolve that issue. The second lesson is that the boards ARE CONFORMAL COATED. It isn't a thick, goopy coating, but they are coated. He did say that if you do coat the board yourself, you will void the warranty on the fan (or at least the board) because you could get it on parts that shouldn't have it, and it could goop up the contacts, etc.
That's interesting. I was worried about my system being too hot, charges to 14.7, so I contacted the company and was told they are tested and good to 15. But.. it squeaked as soon as I installed. They are sending a new motor. Hopefully it'll be one of the new ones. I bought this fan last spring. How do you check for that coating?
I have a custom cargo trailer built for deep-cold, northern use--think ski weekends in the Canadian Rockies with no hookups, yet comfy and fully functional plumbing from an all-electric design with minimal power use.( _Engineered_ RV's, as opposed to those sold by the industry under the name, are actually capable of 4-season use.) My fan in this 6-year-old build is a basic Fan-Tastic fan from a few years ago, slowed / quieted down a bit with an inline resistor, has an insulated (double) lid, and a cover that allows the same usage as a Maxx. It is perfect--never had a moment's trouble or bother with it. In a previous rig I had an LP furnace that ate its motherboards one after the other because the thermal isolation and component quality was so bad. I avoided the Maxx for the same reputational reason. If it's not an engineered, rugged design, it doesn't belong in any "serious" rig.
Thanks for doing the research and the Amazon link. I have bought a lot of the items for my van build using your Amazon links, I appreciate your time and research on the items. I have a fan 7500 that is 2 years old that constantly gives me the dreaded green light of FU when I use the fan. Always a thumbs up 👍.
My fan came with the hand knob and remote control... Another issue in the past has been the clear plastic bulb-lens. For some users it has collected H20 from condensate, so drilling a tiny weep hole in the bottom of the lens fixes that too.
Our back fan has this issue. We just reset the fuse but it’s maybe once every few months. Not a big deal but something I need to address if we sell the van. Also can’t agree more with installing manual only. The remote is another thing to lose and If you can’t open the fan with your hand good luck with the road! 😆
Heads up George: silicone sprays are a big problem if you are doing any painting. The silicone mist can cause serious adhesion issues and they are used in carefully controlled areas in many types of critical manufacturing. Consider creating a lab type hood when using the spray.
@@jeepmor We learn by our mistakes and if we are really really smart we learn by others mistakes. I admit I learned this the hard way. How did you learn this lesson?
Yes I too had a van customer who's Maxx fan board failed . I kept asking her if she got the new board yet . Seems like she waited a long time for the new board . Moved away before she got the board , but I did bypass the board when I came to trouble shoot her no fan issue, so she was able to use her fan . It's a great fan otherwise, but not a fan of high tech fans 😂
Thanks again, I had thought a regulator was what I needed and when I saw your instagram testing it I bought one (sorry before the affiliate link) it has solved the issue for me as well. Thanks again George, you set the standard high and I appreciate your thought processes and content.
I added one for my LED lighting setup for the same reason, I am lucky that our fan motherboard is still alive and that you posted this video. Thanks for sharing George.
Yes. The motherboard models with the #3 in them are, based on communication with AirExel, are now made to operate up to a higher voltage. Another issue is moisture gets into the unsealed motherboard and causes it to crap out after a few years and this has still not been addresses. Owners are disassembling and resealing the motherboards themselves with the sealants you showed.
Do you have information on what the labeling is that would confirm the V3 board? I ask becasue I replaced a board on my van last summer (it took 4+ months to get one in). It DID have a voltage regulator on it and it failed. The board I replaced failed about 4 months later, but there is no obvious way to distinguish that it was a V3 board. However, it did have 04 2022 on a sticker, so I presume it was a very recent board. I'm now going to replace the board again and put in a better voltage regulator. If that doesn't work... out goes the craptastic Maxxair fan.
@@age_of_reason Yes, I'll do that... amazing how cheap these products are. I presume I need to do both sides. Neither one seemed to have any moisture damage.
It's such a good idea that I bought a second one for my Isotherm 85 fridge, just in case! Thank you for your videos and concern for build safety and craftsmanship. Well done!
I love the thermostat. I leave my fan on that setting 24/7. Never had my fan, 6 years old, die. The two things I regret about it are the remote is very cheap and they don't offer a cover which slides off horizontally.
Great info as always George. Had exactly the same problem with my fans before the accident. Just bought two new fans for the new truck conversion. Despite the promises that the problem has ‘been fixed’ I’ve just ordered two regulators from your link. Like you, I’m a belt and braces guy! Thanks for sharing all the research you do! You are a fantastic asset to the community!
Hi RV Doctor Love is in the Air, every .... Thank you for making RV life a better and less worried place to be. A bit unsure about your assistant who seemed to like hanging out with you..... 😉
2 года назад+2
The MaxxFan are quiet… when new. The graphite brushes in the motors chew through the copper contacts pretty quickly and get used themselves. I had to open mine to clean it up to stop the uncannily cricket-like squeaking. Not sure how long until it will come back, but the copper was already almost half-way gone so I bet I won't get more than another year or two (4 total) out of it. I bought a spare motor (US$100, ugh) just in case, short of finding a brushless plug&play replacement. As for the voltages, as you might know the new "C" series boards (in stock at eTrailer, backordered at AirExcel) allegedly have no problem with Lithium-level voltages, but like you I installed buck-boost 12V regulator to be safe… too bad it was after having my first broken board (out of warranty of course). In my case, I elected to bypass the board and have a reversible controller directly wired to the motor. So now I have a nice dimmer on the wall, infinitely adjustable from 0 to 100% with a switch to choose direction. 😎
Thank you for this video, I have a new 4 speed maxxair that will only run on speeds 3 and 4 on shore power but works fine on all 4 speeds just on battery alone. I called maxxair who sent me out a new motor and control board which does the same thing so im going to give this a shot. Thanks again Great info!
George, thanks for being a big help to me twice now. I just installed those small regulators and it is so good to have my fans back! I guess I was lucky the boards weren't too far gone; the regulators seem to fix 'em. I also used your magnet idea for large panels that need to remain removeable but are not opened very often. Super stuff- love your informative and entertaining way of working!
LOL As you said, "and how," I immediately thought of The Little Rascals--and then you supplied a sample of that show! It's like I was programmed to respond with that image in my mind as if I was some kind of Manchurian Candidate. ♥ I think the fan company really lost the bubble on this. I wonder what percentage of their products have encountered such issues. You'd think they would have rushed to fix it.
Great video In the process of replacing the original fantastic vents in our RV. Your video clearly demonstrates what needs to be done to have a hassle free fan thanks again
Ah my Maxxair 7500 died in August; the motherboard. I found one new board after checking with several Aircell service centres. Board has been backordered from manufacturer for months now, one of the service centres told me. I have ordered the voltage regulator off your Amazon link and will treat new board with Silicone when it arrives. Old board lasted 31 months but warranty is only 24 months. Hopefully with the George Mods I will have many trouble free years of use.
One can add a low-dropout V regulator to the supply line on the logic circuits. The motherboard ucontroller is what is sensitive to the over-voltage. The fan motor is fine with higher voltage. Your solution is fine, tho, as most people won't mess with the Mboard.
I have the same maxxair fan and it is wired using the voltage regulator that you recommend. My fan still beeps and shuts off sometimes. So far it has always worked again.
Classic and such great memories. Baby Spanky era was the best. Wow thanks for the sharing the fan info. I wonder if the regulator fixes the problem with other brands
Regulated power is good for the long-term health of any and all motherboard situations that will find their way aboard a Humble, Road vessel, of any kind.. Sounds prudent. Any dedicated electronics charging-station locations in the cabin would do as well having one of those little regulator babies tucked away somewhere…
These clips and humor make this better than the Sunday Comics! So cute those kids! Little Rascals I believe is the show. This is a great fix, George. I was going to buy a Maxxair Fan and this saved the day. Thank you for a wonderful video!
My Maxx Air Maxxfan 7000K (with lift motor and remote) purchased almost 2 years ago has been running great with voltage as high as 14.4V when the battery is full and solar panels are topping off continuously. I have 2 running with no problems. My primary complaint is the air doesn't flow straight down from the fan. The air flow practically hugs the ceiling. Very strange. That's not why I put the fan over the bed. I had to buy another countertop fan to have air blow on me while I sleep. For what it's worth, the 7000k also has a "knurled knob" that can be used to open and close the lid if the motor fails.
That's what I have been doing with my failed motor and it's actually quite nice as I can control how much I open the lid now. With the remote it's either open or shut. Manual openings don't have that problem
Remember depending on length/wire gauge there will be a voltage drop on your wire run so check the voltage right at the fan and see if it's really getting 14 volts.
Thanks for doing these tests George..had a Mutherboard crap out two years ago in the heat of Florida. Replaced it and did the conformal coating thing. Haven’t had a problem since, but I’m gonna add one of these for peace of mind. Thanks for the links!
It specifically states in the AirXcel FAQ page that the deluxe can be open while driving. You, my friend are entitled to a replacement. www.airxcel.com/rv/maxxair/service-support/maxxair-faqs
Highly recommend putting in a DC/DC stable voltage regulator. I purchased one on Amazon that went from any voltage and regulated it down to 12 volts I've seen videos where they put them in the fan but that's a pain I put it right next to my fuse box My fan wasn't working for the longest time I tried this before replacing parts and it works great.
i put a voltage regulator in front of my fan and still get the beeps and shut down. took out the fuse to retry, turned off solar, getting 12.22v out of the regulator. would you assume its the control board then?
@@lukemccrae1617 I would recommend calling maxxfan and they can help trouble shoot the issue. They did tell me that my motor was bad and that was my issue, so there not right all the time. I took a chance on the voltage regulator and it worked. My guess is the board is bad. The new boards are able supposably to handle the voltage coming out of your lithiums. I would still use the voltage regulator in line either way.
I spoke with Tech Support at AIRXCEL about both these issues. Regarding voltage: They said the PCB board can handle a voltage range of 10.3V-15V. They mentioned sometimes a spike from a solar charge controller can occur. That, plus high voltage from lithiums, can bump it over 15V and start to cause issues. To avoid, they suggested to put in a regulator and set at optimal voltage of 12.9V. I'm not sure if the PCB could always handle this range and I did not think to ask if/when a breakpoint occurred. What month/year did Melissa communicate her fan issue? Regarding moisture: They mentioned they were aware of this issue and started adding a coating on the PCB board in 2017 to address this issue. Have you seen this failure on fans with a manf. date after 2017?
@@HumbleRoad Be aware that advising people to coat the board violates the terms or warranty, so you are SOL if you have a problem after that (unless you are deceitful and do not tell them about the added coating, I suppose).
I’ve discovered that the material covering the membrane buttons are prone to cracking. I presume it’s due to heat. Mine started cracking one year in. Materials were pre-covid.
I have the same issue with the membrane buttons. Mine cracked in less than one year and after doing a cross country trip moving through hot and cold weather. I need to reach out to the company and see about replacing it. How did you manage with yours?
We instaled many of them with lifepo or gel bateries and had never single problem with them at all. maybe there water of humid got into the maxxair but we never had problem. Running 14.2V in van system
🤔 It would seem that Maxx Air, being aware of these limitations, would/should do these factory manufacturing fixes to preserve their reputation for quality/reliability. 😎
Wow great job figuring that out!!! I have had this problem since upgrading my solar panels to (3) 360w panels. Middle of day and the fan will not function. Could this be a problem for a lot of these crappy 12 volt products? I swear after watching this it has to be the fan problem as well as my instyconnect internet router kicking off, and even the inverter itself kicking off midday.
I am installing 2 MaxxAir fans. One like you show here today the large fancy two way model and a dome fan replacement for one not working in a 22 year old Class B+ RV bought this past January. Will the Dome fan came without it's extra items. No instruction, no interior trim piece of cover for side installation and no extension tube if needed. Even the fan blades themselves were not attached and rattled around under the dome cover. So until I work out this issue with SELLER I'm not installing either fan because I wanted it to be a one day job for both and as few trips onto the RV roof then. Anyway had a kick with your Video but more important talking to heart your controller theory. While I am stuck waiting on the bad seller to set it all right I'm going to look into your products used today. I have some silicone spray and two kinds. One may be a good match or I'll look at buying your recommendation. Good video and FUNNY too. However I did want to HEAR that band actually play some music.
Been dealing with this for 6 months finally got that new board circuit board FedEx and delivered today and still this fan is not right very disappointed with the max air fan
As usual great video George! Darn it! I wish I would have known about your amazon link, I ordered a Maxx Air fan last week from Amazon. I will try to remember to order the rest of my Van build components through your link in order to help support and to show thanks for sharing your knowledge! Also because of your video, I had to go and find that full clip of the Submarine band! LOL! Thanks for bringing back some fond memories!
And then she sold it 😂 just a cheap 5-24v voltage regulator should do it. That big one has the heatsink because it's able to regulate higher amperage or a larger difference in voltage. But mainly the amperage. We are only knocking down a few volts and a small amount of amperage, 4 amps ish I think.
George, Great video. I think you're right on track with your new R & D lab. If you ever want to expand, please consider Denver, CO. I'd love to work with Spanky and all the guys. Mike
Lots of people tape off the IC and a few other components on the board before coating with conformal to keep good heat radiation afterwards. Another weakness is the fan motors they use are junk.
I spray circuit boards for my work. Any heatsink, connectors, and thru hole mounted components should be masked from the conformal coat. It can cause contact and over heating issues.
@@pamelabraman7217 Can you recommend a link where I can see what the components you mentioned look like? I'd like to coat only what should be coated, but I'm not sure I could identify what to avoid. Thanks!
Today my MaxxFan broke after 6 month, on a regulated 12v circuit, using a voltage regulator that looks exactly like yours (the one with the heatsink). I measured voltage with an Oscilloscope, very nice 12.1V, no peaks , smooth line. Anyways the MaxxFan started beeping and cannot be controlled via the panel buttons. The electrical design is just bad. Again, my MaxxFan came March 2024, it seems they improved the design, to now break even a regulator is used 😂. A question for the pro, is there a way to silence the hood lifter gear box? First night of operation I almost suffered a heart attack when the thing closed. They could have just added a night mode , where the fan motor just stops at a certain temperature - leaving the hood open.
HI! Thanks for the helpful video -- It will probably be even more helpful to my son because he's my do boy :D just wanted to give thnaks and gice you a headsup that the Amazon link to the MaxxAir Fan is no longer working in case you'd like to fix your affiliate link -- thanks again!
I bought a max air fan and it would only run in one direction right out of the box. I waited several months to get a new circuit board,-they kept saying the parts were stuck in customs, stuck on a ship, or on a train. Finally after about 4 calls I told them I wanted a entire new fan, and the board showed up about a week later. New one works great so far.
(a) George, might it not be a good idea to incorporate a voltage regulator for the entire house? Thank you for sourcing the regulators. I'll definitely pick a couple up. (b) You are much more tolerant of a big company with a large and complex supply chain and huge distribution network that knowingly sold tens, if not hundreds of thousands of defective products and can't keep up with warranty demand, than a small company with a modest supply chain and no distribution network but with a quality product that can't keep up with initial demand. (c) I learned of the Maxxair fan problem while my van was being built (summer 2020). I asked my builder to put in voltage regulators. He refused saying AirExcel would replace the boards or the fans if they ever went out. That in itself was a problem more than the fans but, I went along with it. And to be precise, AirExcel would supply the parts, but I'd have to replace the fans. (d) My manual fan did experience a voltage ripple one time and stopped working. Pulling the fuse and putting it back got it working again; that was about a year ago. The remote fan - and the remote is ridiculous, it can't sense anything unless you are directly under the fan and point the remote at it at which point it's useless you might as well just twist the knob by hand - the lift mechanism disintegrated. AirExcel sent new mechanicals and a motherboard as well. (e) This is what I'm talking about George! These vans need service after the sale and no, it's not going to Cramping World
You are wrong about your reference to C-Head. As I understand it, the original founder sold the company, the new owners closed their doors, let all employees go, but are still taking orders through their website. I don't care how big or small you are...that is theft. Apologetic to AirXcell?!!! I said I HATE that fan! I demonstrated disdain for having to come up with a fix.
I’ve saved your affiliate link, and any associated products that I later bookmark separately get an HRL (Humble Road Laboratory) approved notation added to the bookmark.
@@HumbleRoad I have a lot of respect for your work. That may sound odd, but I get what and WHY you do things the way you do them. My less-than-friends often comment about how I work is like building a watches.
I don't know how to thank you enough for this info. I am installing two maxxair fans now, and the timing for this info couldn't be better. Thank-you George for sharing!!!
Glad it helped. Get some official info on the proper use of the silicon spray. Some have commented that certain areas of the board should be masked off.
@@HumbleRoad will investigate further, thanks. I will be using the 422C product as MG chemicals is replacing 422B with it, according to their website. Thanks again.
And if I'd have just waited 3 minutes more into the video... Tada voltage regulator :-) In my world - computer control and electronics - voltage regulators or buck converters are key. Especially in Mobile and industrial environments where power is not always regulated. It's an elegantly simple solution and I'm absolutely amazed that the fan boards did not include them from the start. Everything we design uses voltage regulators.
I cannot get a straight answer from AirXcel, what is the Amperage threshold in the units that you use ? I see them from 3A to 10A, all while restricting voltage to 12V …..
Sounds like a major liability lawsuit on those fans. A vehicle fan that can't handle over 12vdc? That's BS right there. Not being coated when one can expect moisture to get to the board? That is shameful!
I was looking into replacing the 12 volt AGM battery in my Casita with a Lithium battery, but had read that the Max Fan can fail with Lithium batteries, apparently due to the higher voltage that they produce.
it's not that lithium batteries run at a higher voltage it's that when they get to 90% full they need a higher voltage from the charging source to get them to 100%
@@aerobic247 Well, yes and no. Yes they need a higher voltage coming in that what the battery is at to pull in a charge. But that's largely irrelevant to the issue with the fans, which is that they don't like those high voltages, the level that things get up to when topping off a lithium iron phosphate battery. You can generally push them up to 14.6v, but then when the charge is off, the voltage will drop to a "resting" level of around 13.4-13.6 - which apparently is in the danger zone for these fans (or at least, older fans prior to the supposed fix).
I agree with you that the manual option is a better way to go , for me I usually leave the vent open all season and close it up when the weather starts to get cold . I have a question about these fans. Could I turn the fan on and off from a switch I add located near my sitting location ? I guess I need to know if the max air power switch will stay in the on position so I can turn it off and on with my added switch.
I just had the same question. Maxxair said although you can do it (it will work but speed will reset each time) they don't recommend it because the "fans are designed to have a constant 12V feed, and when an external switch is used there will be a short spike in voltage every time the switch is turned on, which over time could potentially cause issues with the circuit board on the vent". My goal was to turn it on and off from an app on my phone and with Alexa. Which I will probably do with a external switch bot to keep a constant 12v sent from the battery and keep previous settings when going on and off. Hope that helps
I agree that Maxxairs are incredibly unreliable in the environment in which they're intended. I refuse to use Maxxair in my builds BECAUSE the one I had fried *three* motherboards on a *regulated* DC circuit @13.2vdc. I was an electronic technician for years, and whoever designed that should be fired. I use Fantastic, instead. No problems. Just as quiet. Agree about the conformal coating - again - in a VERY humid environment, it's criminal to not be properly protected with conformal coating. You can fix them, I suppose, but these two things, so BASIC in the use of these fans makes me doubt any other part of the design.
The fan regulator info was great, but I stayed for the Little Rascals. 😃😃. Thanks for the flashback. Seemed to be a much simpler time.
Former NASA engineer concurs w findings! Great diagnosis and fix on this! I'm on Spotify, YT Applemusic and touring a town near you w my broken maxxair fan😂.
George: Loved visiting the new Research and Development Laboratory. Of course, after years of watching Humble Road episodes, I was already familiar with the Mad Scientist that runs the place.😵💫🤔🥰
The same voltage regulator is also needed (and in use) for our 4G router. It works perfect.
George, my 5ft 1in wife would disagree with you about the need for a remote on our Maxair fan. She is not a climber. Happy wife, happy life!
love that Ron took notes the whole time!!! When you guys commit, you commit!
My van came last week, today is Day 1 of my build and after a year of watching you, George, I've decided to take her on myself! I've watched the floor videos more times than I can count!
That is awesome! Go for it! Send pictures! 👍
GEORGE: LOVED the video and seeing my favorite "our gang" show ❤💪. Your wit, ingenuity and taste is impeccable... Father Healy or Shaw taught you well....😊
Thanks George. I have the fan with the remote. Had trouble with it years ago but connecting for a while and disconnecting the power solved it. Now go forward 6 years. Just went other day to connect the power and the board blew. Puff. Done. Fortunately when I had the trouble the first time I called them under warranty and they sent a new board which I still have in the box. So I just ordered the small transformer and that spray. Once they come I’ll be dismantling my unit and swapping the board within your new design. Hopefully that will solve it. It is so strange that they would have this problem. I never noticed the voltage limitation when I installed. 13.6. That’s no where near enough. My agm battery needs 14.6 to charge. Clearly they must assume rv voltages never exceed 13.6 which just isn’t the case. Even an a vehicular situation it is not unusual to have 14.1 volts in the electrical system when alternator is wide open charging. Someone clearly wasn’t thinking. Probably the new board they sent me is fine. But I’m with you. Belt and suspenders. Fool me once shame on you. Fool me twice shame on me. I’ll regulate the voltage for the fan. Thanks again. I was going to do this research myself. Thanks for solving it for me.
Its so great you did a video on this. I almost purchased that model until I saw this issue in a number of reviews. Such a simple oversight on their part. Glad they are fixing it. I went with an older version fan (with the manual knob).
I just recieved my replacement board after making a warranty claim 6 months ago...I'll be sealing the PCB with CRC Urathane Seal Coat and installing the voltage regulator you recommend. Thanks for the video!
I had a conversation with Maxxair today about my failed motherboards (I have one fan that had the MB fail twice on it, and I have it on regulated power).
They are sending me a new fan because they told me that the MB failure is likely due to a MOTOR problem, not the voltage problem that most people blame it on. He said they had a brushed motor in there that would accumulate the carbon from the brushes and then it will essentially draw too much power through the MB, eventually leading to the MB failing. Essentially it was a design flaw in the motor that has since been corrected.
So not all issues are due to overvoltage! That is the first lesson. They believe that the V3 boards (which started shipping out starting in early 2022) resolve that issue.
The second lesson is that the boards ARE CONFORMAL COATED. It isn't a thick, goopy coating, but they are coated. He did say that if you do coat the board yourself, you will void the warranty on the fan (or at least the board) because you could get it on parts that shouldn't have it, and it could goop up the contacts, etc.
That's interesting. I was worried about my system being too hot, charges to 14.7, so I contacted the company and was told they are tested and good to 15.
But.. it squeaked as soon as I installed. They are sending a new motor. Hopefully it'll be one of the new ones. I bought this fan last spring. How do you check for that coating?
I don’t see the links
@markoshun I think they are all coated as a matter of manufacture specifications... I think HR promoting that is very poor advice.
I have a custom cargo trailer built for deep-cold, northern use--think ski weekends in the Canadian Rockies with no hookups, yet comfy and fully functional plumbing from an all-electric design with minimal power use.( _Engineered_ RV's, as opposed to those sold by the industry under the name, are actually capable of 4-season use.) My fan in this 6-year-old build is a basic Fan-Tastic fan from a few years ago, slowed / quieted down a bit with an inline resistor, has an insulated (double) lid, and a cover that allows the same usage as a Maxx. It is perfect--never had a moment's trouble or bother with it. In a previous rig I had an LP furnace that ate its motherboards one after the other because the thermal isolation and component quality was so bad. I avoided the Maxx for the same reputational reason. If it's not an engineered, rugged design, it doesn't belong in any "serious" rig.
Learned soooooo much! My MaxxAir pooped out and now I know why❣️🌝🙏💖
I have been researching this for so long. Your post has been the definitive answer to all my questions. Thank you.
Thanks for doing the research and the Amazon link. I have bought a lot of the items for my van build using your Amazon links, I appreciate your time and research on the items.
I have a fan 7500 that is 2 years old that constantly gives me the dreaded green light of FU when I use the fan.
Always a thumbs up 👍.
You don't need to push volts and amps into it. You create a potential difference and the electrons will flow just fine without any pushing hehe
My fan came with the hand knob and remote control... Another issue in the past has been the clear plastic bulb-lens. For some users it has collected H20 from condensate, so drilling a tiny weep hole in the bottom of the lens fixes that too.
I had the same problem with my MaxxAir fan. Three years ago I installed a voltage regulator on the line to the fan, and I have had no issues since.
did you install the regulator between the 12v fuse block and the fan?
Our back fan has this issue. We just reset the fuse but it’s maybe once every few months. Not a big deal but something I need to address if we sell the van. Also can’t agree more with installing manual only. The remote is another thing to lose and If you can’t open the fan with your hand good luck with the road! 😆
Heads up George: silicone sprays are a big problem if you are doing any painting. The silicone mist can cause serious adhesion issues and they are used in carefully controlled areas in many types of critical manufacturing. Consider creating a lab type hood when using the spray.
Or consider conformal coating!
LOL, if you can't prep for silicone contamination painting, you shouldn't be painting.
@@jeepmor We learn by our mistakes and if we are really really smart we learn by others mistakes. I admit I learned this the hard way.
How did you learn this lesson?
Yes
I too had a van customer who's Maxx fan board failed .
I kept asking her if she got the new board yet .
Seems like she waited a long time for the new board .
Moved away before she got the board , but I did bypass the board when I came to trouble shoot her no fan issue, so she was able to use her fan .
It's a great fan otherwise, but not a fan of high tech fans 😂
Thanks again, I had thought a regulator was what I needed and when I saw your instagram testing it I bought one (sorry before the affiliate link) it has solved the issue for me as well. Thanks again George, you set the standard high and I appreciate your thought processes and content.
Great to hear!
I added one for my LED lighting setup for the same reason, I am lucky that our fan motherboard is still alive and that you posted this video. Thanks for sharing George.
Glad I could help!
Yes. The motherboard models with the #3 in them are, based on communication with AirExel, are now made to operate up to a higher voltage. Another issue is moisture gets into the unsealed motherboard and causes it to crap out after a few years and this has still not been addresses. Owners are disassembling and resealing the motherboards themselves with the sealants you showed.
Do you have information on what the labeling is that would confirm the V3 board? I ask becasue I replaced a board on my van last summer (it took 4+ months to get one in). It DID have a voltage regulator on it and it failed. The board I replaced failed about 4 months later, but there is no obvious way to distinguish that it was a V3 board. However, it did have 04 2022 on a sticker, so I presume it was a very recent board. I'm now going to replace the board again and put in a better voltage regulator. If that doesn't work... out goes the craptastic Maxxair fan.
@@mjmdiver1137 Just make sure you seal/spray the new circuit board so this doesn't happen again.
@@age_of_reason Yes, I'll do that... amazing how cheap these products are. I presume I need to do both sides.
Neither one seemed to have any moisture damage.
I purchased mine in 2016. It ran without issue at least until July of 2023 when I sold the van. I'm looking to buy another for my camper.
It's such a good idea that I bought a second one for my Isotherm 85 fridge, just in case! Thank you for your videos and concern for build safety and craftsmanship. Well done!
I love the thermostat. I leave my fan on that setting 24/7. Never had my fan, 6 years old, die. The two things I regret about it are the remote is very cheap and they don't offer a cover which slides off horizontally.
Great solution to the problem, but I love your guy with the clipboard in the back
Nice to have this neatly in one video. Back in the day I had to scour multiple forums and do testing myself to figure this out.
Great info as always George. Had exactly the same problem with my fans before the accident. Just bought two new fans for the new truck conversion. Despite the promises that the problem has ‘been fixed’ I’ve just ordered two regulators from your link. Like you, I’m a belt and braces guy! Thanks for sharing all the research you do! You are a fantastic asset to the community!
Hi RV Doctor Love is in the Air, every .... Thank you for making RV life a better and less worried place to be. A bit unsure about your assistant who seemed to like hanging out with you..... 😉
The MaxxFan are quiet… when new. The graphite brushes in the motors chew through the copper contacts pretty quickly and get used themselves. I had to open mine to clean it up to stop the uncannily cricket-like squeaking. Not sure how long until it will come back, but the copper was already almost half-way gone so I bet I won't get more than another year or two (4 total) out of it. I bought a spare motor (US$100, ugh) just in case, short of finding a brushless plug&play replacement.
As for the voltages, as you might know the new "C" series boards (in stock at eTrailer, backordered at AirExcel) allegedly have no problem with Lithium-level voltages, but like you I installed buck-boost 12V regulator to be safe… too bad it was after having my first broken board (out of warranty of course). In my case, I elected to bypass the board and have a reversible controller directly wired to the motor. So now I have a nice dimmer on the wall, infinitely adjustable from 0 to 100% with a switch to choose direction. 😎
Thank you for this video, I have a new 4 speed maxxair that will only run on speeds 3 and 4 on shore power but works fine on all 4 speeds just on battery alone. I called maxxair who sent me out a new motor and control board which does the same thing so im going to give this a shot. Thanks again Great info!
George, thanks for being a big help to me twice now. I just installed those small regulators and it is so good to have my fans back! I guess I was lucky the boards weren't too far gone; the regulators seem to fix 'em. I also used your magnet idea for large panels that need to remain removeable but are not opened very often. Super stuff- love your informative and entertaining way of working!
Glad to help!
LOL As you said, "and how," I immediately thought of The Little Rascals--and then you supplied a sample of that show! It's like I was programmed to respond with that image in my mind as if I was some kind of Manchurian Candidate. ♥
I think the fan company really lost the bubble on this. I wonder what percentage of their products have encountered such issues. You'd think they would have rushed to fix it.
Your videos are always informative. Thank you for being so clear and concise.
Great video
In the process of replacing the original fantastic vents in our RV. Your video clearly demonstrates what needs to be done to have a hassle free fan thanks again
Glad it was helpful!
Our Gang Comedies/The Little Rascals. You put a big smile on my face this morning. As always, a great informative video.
Glad you enjoyed it
Ah my Maxxair 7500 died in August; the motherboard. I found one new board after checking with several Aircell service centres. Board has been backordered from manufacturer for months now, one of the service centres told me. I have ordered the voltage regulator off your Amazon link and will treat new board with Silicone when it arrives. Old board lasted 31 months but warranty is only 24 months. Hopefully with the George Mods I will have many trouble free years of use.
Good Morning, George and HR fans! Another helpful one, for sure.
Wow! I loved Sparky and our gang as a kid. Thanks
I've got a 24V battery with a step down converter (13.8) running my fan, among other items. No issues after 2 years.
great psa!!!
you and your assistant are the absolute best!!!
i don't have a van or a fan and don't know why i watched this but
One can add a low-dropout V regulator to the supply line on the logic circuits. The motherboard ucontroller is what is sensitive to the over-voltage. The fan motor is fine with higher voltage. Your solution is fine, tho, as most people won't mess with the Mboard.
Oh that's a neat idea! Are there wires to tap into for the motherboard or does this require soldering straight into the motherboard?
I have the same maxxair fan and it is wired using the voltage regulator that you recommend. My fan still beeps and shuts off sometimes. So far it has always worked again.
Same. Mines been on a 12v reg since new and but it will still crap out and beep sometimes.
Classic and such great memories. Baby Spanky era was the best.
Wow thanks for the sharing the fan info. I wonder if the regulator fixes the problem with other brands
Ordered one from your Amazon link. Thank you for all your knowledge.
I came over to the comment section because I normally just watch on my TV. I came in to say - voltage regulator - but everybody beat me to it 😂
Regulated power is good for the long-term health of any and all motherboard situations that will find their way aboard a Humble, Road vessel, of any kind..
Sounds prudent.
Any dedicated electronics charging-station locations in the cabin would do as well having one of those little regulator babies tucked away somewhere…
Very good advice! I'll install two. The laptops and cell phones are delicate machines.
"the horse has already left the barn" true that. fool me once. thanks for this info!
These clips and humor make this better than the Sunday Comics! So cute those kids! Little Rascals I believe is the show.
This is a great fix, George. I was going to buy a Maxxair Fan and this saved the day. Thank you for a wonderful video!
Loved the old movie clips.. thanks for the info🚎
I just installed one, I used a stabiliser to keep the power at 12volt.
My Maxx Air Maxxfan 7000K (with lift motor and remote) purchased almost 2 years ago has been running great with voltage as high as 14.4V when the battery is full and solar panels are topping off continuously. I have 2 running with no problems.
My primary complaint is the air doesn't flow straight down from the fan. The air flow practically hugs the ceiling. Very strange. That's not why I put the fan over the bed. I had to buy another countertop fan to have air blow on me while I sleep.
For what it's worth, the 7000k also has a "knurled knob" that can be used to open and close the lid if the motor fails.
That's what I have been doing with my failed motor and it's actually quite nice as I can control how much I open the lid now. With the remote it's either open or shut. Manual openings don't have that problem
Remember depending on length/wire gauge there will be a voltage drop on your wire run so check the voltage right at the fan and see if it's really getting 14 volts.
@@fritzkabeano1969 I have about 20 feet of 12AWG duplex. Voltage drop is less than half a volt at full power
I read that if you want the air to blow straight on you, you have to flip the blades die to their curvature.
Thanks for a trip down memory lane! ❤️ Our Gang.
Thanks for doing these tests George..had a Mutherboard crap out two years ago in the heat of Florida. Replaced it and did the conformal coating thing. Haven’t had a problem since, but I’m gonna add one of these for peace of mind. Thanks for the links!
Thank you!!! The “green light of death” drives me crazy.
I wouldn’t suggest driving with the fan shroud open. We’ve had one break the raising mechanism while driving.
It specifically states in the AirXcel FAQ page that the deluxe can be open while driving. You, my friend are entitled to a replacement. www.airxcel.com/rv/maxxair/service-support/maxxair-faqs
Came for the fan... Stayed for the band! ☺️
Thank you for the video! We used your link to get the voltage under control and fix the fan in our little Casita travel trailer.
Highly recommend putting in a DC/DC stable voltage regulator. I purchased one on Amazon that went from any voltage and regulated it down to 12 volts I've seen videos where they put them in the fan but that's a pain I put it right next to my fuse box My fan wasn't working for the longest time I tried this before replacing parts and it works great.
i put a voltage regulator in front of my fan and still get the beeps and shut down. took out the fuse to retry, turned off solar, getting 12.22v out of the regulator. would you assume its the control board then?
@@lukemccrae1617 I would recommend calling maxxfan and they can help trouble shoot the issue. They did tell me that my motor was bad and that was my issue, so there not right all the time. I took a chance on the voltage regulator and it worked. My guess is the board is bad. The new boards are able supposably to handle the voltage coming out of your lithiums. I would still use the voltage regulator in line either way.
@@mrfixer987 just replaced the control board with a pulse width modifier and a voltage regulator, seems to be working well!
@@lukemccrae1617 just in time for summer!
I spoke with Tech Support at AIRXCEL about both these issues.
Regarding voltage:
They said the PCB board can handle a voltage range of 10.3V-15V. They mentioned sometimes a spike from a solar charge controller can occur. That, plus high voltage from lithiums, can bump it over 15V and start to cause issues. To avoid, they suggested to put in a regulator and set at optimal voltage of 12.9V.
I'm not sure if the PCB could always handle this range and I did not think to ask if/when a breakpoint occurred.
What month/year did Melissa communicate her fan issue?
Regarding moisture:
They mentioned they were aware of this issue and started adding a coating on the PCB board in 2017 to address this issue.
Have you seen this failure on fans with a manf. date after 2017?
I install a voltage regulator for each fan in my builds. And yes, fans manufactured after 2017 are having issues.
@@HumbleRoad Be aware that advising people to coat the board violates the terms or warranty, so you are SOL if you have a problem after that (unless you are deceitful and do not tell them about the added coating, I suppose).
I’ve discovered that the material covering the membrane buttons are prone to cracking. I presume it’s due to heat. Mine started cracking one year in. Materials were pre-covid.
I have the same issue with the membrane buttons. Mine cracked in less than one year and after doing a cross country trip moving through hot and cold weather. I need to reach out to the company and see about replacing it. How did you manage with yours?
@@agentbey Mine are still holding together, but the surfaces feel rough and sharp. I fear it’s going to fall apart or delaminate any day now.
@@ytJnC You just described the exact condition as mine.
We instaled many of them with lifepo or gel bateries and had never single problem with them at all. maybe there water of humid got into the maxxair but we never had problem. Running 14.2V in van system
Check voltage right at fan and see if it's 14 volts
@@fritzkabeano1969 i am charging batteries to 14.2V lifepo so i have in whole car around 14V depend on length and size of cable. all is good so far.
I love the band. Keep them coming
Miss the Rascals. Bringing me back.
🤔 It would seem that Maxx Air, being aware of these limitations, would/should do these factory manufacturing fixes to preserve their reputation for quality/reliability. 😎
Wow great job figuring that out!!! I have had this problem since upgrading my solar panels to (3) 360w panels. Middle of day and the fan will not function. Could this be a problem for a lot of these crappy 12 volt products? I swear after watching this it has to be the fan problem as well as my instyconnect internet router kicking off, and even the inverter itself kicking off midday.
Makes me happy with my old school fan
I am installing 2 MaxxAir fans. One like you show here today the large fancy two way model and a dome fan replacement for one not working in a 22 year old Class B+ RV bought this past January. Will the Dome fan came without it's extra items. No instruction, no interior trim piece of cover for side installation and no extension tube if needed. Even the fan blades themselves were not attached and rattled around under the dome cover. So until I work out this issue with SELLER I'm not installing either fan because I wanted it to be a one day job for both and as few trips onto the RV roof then. Anyway had a kick with your Video but more important talking to heart your controller theory. While I am stuck waiting on the bad seller to set it all right I'm going to look into your products used today. I have some silicone spray and two kinds. One may be a good match or I'll look at buying your recommendation. Good video and FUNNY too. However I did want to HEAR that band actually play some music.
Been dealing with this for 6 months finally got that new board circuit board FedEx and delivered today and still this fan is not right very disappointed with the max air fan
As usual great video George! Darn it! I wish I would have known about your amazon link, I ordered a Maxx Air fan last week from Amazon. I will try to remember to order the rest of my Van build components through your link in order to help support and to show thanks for sharing your knowledge! Also because of your video, I had to go and find that full clip of the Submarine band! LOL! Thanks for bringing back some fond memories!
And then she sold it 😂 just a cheap 5-24v voltage regulator should do it. That big one has the heatsink because it's able to regulate higher amperage or a larger difference in voltage. But mainly the amperage. We are only knocking down a few volts and a small amount of amperage, 4 amps ish I think.
George, Great video. I think you're right on track with your new R & D lab. If you ever want to expand, please consider Denver, CO. I'd love to work with Spanky and all the guys. Mike
Lots of people tape off the IC and a few other components on the board before coating with conformal to keep good heat radiation afterwards. Another weakness is the fan motors they use are junk.
I spray circuit boards for my work. Any heatsink, connectors, and thru hole mounted components should be masked from the conformal coat. It can cause contact and over heating issues.
The whole fan is junk it just happens that it’s the best junk available.
Flettner Slimline ….
@@pamelabraman7217 Can you recommend a link where I can see what the components you mentioned look like? I'd like to coat only what should be coated, but I'm not sure I could identify what to avoid. Thanks!
Today my MaxxFan broke after 6 month, on a regulated 12v circuit, using a voltage regulator that looks exactly like yours (the one with the heatsink). I measured voltage with an Oscilloscope, very nice 12.1V, no peaks , smooth line. Anyways the MaxxFan started beeping and cannot be controlled via the panel buttons. The electrical design is just bad. Again, my MaxxFan came March 2024, it seems they improved the design, to now break even a regulator is used 😂.
A question for the pro, is there a way to silence the hood lifter gear box? First night of operation I almost suffered a heart attack when the thing closed. They could have just added a night mode , where the fan motor just stops at a certain temperature - leaving the hood open.
Thank you for the flash back memories ♥️
I was raised on the Little Rascals and Abbott & Costello.
@@HumbleRoad
Wow… I would never have guessed you were old enough.
Oh, I bet you say that to all the boys! 😉
@@HumbleRoad 😂🤣😂🤣😂🤣
HI! Thanks for the helpful video -- It will probably be even more helpful to my son because he's my do boy :D just wanted to give thnaks and gice you a headsup that the Amazon link to the MaxxAir Fan is no longer working in case you'd like to fix your affiliate link -- thanks again!
I bought a max air fan and it would only run in one direction right out of the box. I waited several months to get a new circuit board,-they kept saying the parts were stuck in customs, stuck on a ship, or on a train. Finally after about 4 calls I told them I wanted a entire new fan, and the board showed up about a week later. New one works great so far.
Great info tainment George
Yup. I put 2 in my rig last summer and they have both quit working. I sent a message on their website - no response.
Keep trying. I smell a class action suit
I just added some 20 amp diodes to mine to drop the voltage.
(a) George, might it not be a good idea to incorporate a voltage regulator for the entire house? Thank you for sourcing the regulators. I'll definitely pick a couple up.
(b) You are much more tolerant of a big company with a large and complex supply chain and huge distribution network that knowingly sold tens, if not hundreds of thousands of defective products and can't keep up with warranty demand, than a small company with a modest supply chain and no distribution network but with a quality product that can't keep up with initial demand.
(c) I learned of the Maxxair fan problem while my van was being built (summer 2020). I asked my builder to put in voltage regulators. He refused saying AirExcel would replace the boards or the fans if they ever went out. That in itself was a problem more than the fans but, I went along with it. And to be precise, AirExcel would supply the parts, but I'd have to replace the fans.
(d) My manual fan did experience a voltage ripple one time and stopped working. Pulling the fuse and putting it back got it working again; that was about a year ago.
The remote fan - and the remote is ridiculous, it can't sense anything unless you are directly under the fan and point the remote at it at which point it's useless you might as well just twist the knob by hand - the lift mechanism disintegrated. AirExcel sent new mechanicals and a motherboard as well.
(e) This is what I'm talking about George! These vans need service after the sale and no, it's not going to Cramping World
(b) is the same for class B & other rv manufacturers… at least based on my recent experience.
@@lindahardy8713in (b) I was referring to George's unprofessional rage against C-Head while being apologetic for AirExcel. He knows.
You are wrong about your reference to C-Head. As I understand it, the original founder sold the company, the new owners closed their doors, let all employees go, but are still taking orders through their website. I don't care how big or small you are...that is theft. Apologetic to AirXcell?!!! I said I HATE that fan! I demonstrated disdain for having to come up with a fix.
Looks Like It’s the End of the Road for the Ram ProMaster City. Perhaps the 1500 ProMaster may be a good fit.
Yes, I ordered two 118 WB Promaster standard roof vans. But we still have one more year of Promaster City orders.
You said Frankenstein and I immediately imagined the actor the great Peter Boyle growling as the Monster from "Young Frankenstein" :o)
Me too! What knockers!
Came for the fan ... became a fan of the band.
I’ve saved your affiliate link, and any associated products that I later bookmark separately get an HRL (Humble Road Laboratory) approved notation added to the bookmark.
Thank you!
@@HumbleRoad I have a lot of respect for your work. That may sound odd, but I get what and WHY you do things the way you do them. My less-than-friends often comment about how I work is like building a watches.
I don't know how to thank you enough for this info. I am installing two maxxair fans now, and the timing for this info couldn't be better. Thank-you George for sharing!!!
Glad it helped. Get some official info on the proper use of the silicon spray. Some have commented that certain areas of the board should be masked off.
@@HumbleRoad will investigate further, thanks. I will be using the 422C product as MG chemicals is replacing 422B with it, according to their website. Thanks again.
Good, Pete. Please share your findings here with our Humble community. 👍
I wonder if Maxxair has corrected this problem in their newer models? Do you still install regulators in your current builds?
I don't know if Maxxair has addressed the issue. I, however, install a voltage regulator in every van!
I had to replace a motherboard on mine too... it totally crapped out
The hunble road lab reminds me to Blendtechs "will it blend?" Advertising. BtW will a Max Air Fan blend????
I'm very close to trying to blend a MaxxAir fan!
And if I'd have just waited 3 minutes more into the video... Tada voltage regulator :-)
In my world - computer control and electronics - voltage regulators or buck converters are key. Especially in Mobile and industrial environments where power is not always regulated. It's an elegantly simple solution and I'm absolutely amazed that the fan boards did not include them from the start. Everything we design uses voltage regulators.
Do they always crap out at a certain voltage, or do they often crap out at a certain voltage; or do they sometimes crap out at a certain voltage?
Looked for the link to that spray you mentioned but couldn’t find it.
I cannot get a straight answer from AirXcel, what is the Amperage threshold in the units that you use ? I see them from 3A to 10A, all while restricting voltage to 12V …..
The voltage regulators (read: restrictors) put out between 12 and 12.4 volts. Consistenly.
Sounds like a major liability lawsuit on those fans. A vehicle fan that can't handle over 12vdc? That's BS right there. Not being coated when one can expect moisture to get to the board? That is shameful!
I was looking into replacing the 12 volt AGM battery in my Casita with a Lithium battery, but had read that the Max Fan can fail with Lithium batteries, apparently due to the higher voltage that they produce.
it's not that lithium batteries run at a higher voltage it's that when they get to 90% full they need a higher voltage from the charging source to get them to 100%
@@aerobic247 Ahh, thanks for clarifying
@@aerobic247 Well, yes and no. Yes they need a higher voltage coming in that what the battery is at to pull in a charge. But that's largely irrelevant to the issue with the fans, which is that they don't like those high voltages, the level that things get up to when topping off a lithium iron phosphate battery. You can generally push them up to 14.6v, but then when the charge is off, the voltage will drop to a "resting" level of around 13.4-13.6 - which apparently is in the danger zone for these fans (or at least, older fans prior to the supposed fix).
@@wanderingzythophile9083 why is that irrelevant?
I agree with you that the manual option is a better way to go , for me I usually leave the vent open all season and close it up when the weather starts to get cold .
I have a question about these fans.
Could I turn the fan on and off from a switch I add located near my sitting location ?
I guess I need to know if the max air power switch will stay in the on position so I can turn it off and on with my added switch.
I just had the same question. Maxxair said although you can do it (it will work but speed will reset each time) they don't recommend it because the "fans are designed to have a constant 12V feed, and when an external switch is used there will be a short spike in voltage every time the switch is turned on, which over time could potentially cause issues with the circuit board on the vent". My goal was to turn it on and off from an app on my phone and with Alexa. Which I will probably do with a external switch bot to keep a constant 12v sent from the battery and keep previous settings when going on and off. Hope that helps