Can't trust anyone who charges a fully charged battery. Why would anyone do that? In a typical scenario where a solar panel is used, such as on a car or boat, there is usually a draw on the battery. The solar panel should then be correctly sized to compensate for the draw and self-discharge, resulting in a small overall drain or gain that isn't going to produce much harm. Small panels sold in retail are usually deliberately under powered, and there's no risk of harm for the intended purpose. Also, as the battery becomes full, it would resist charging. Small panels don't have the power to over come that resistance. It's all about being appropriate. You don't be charging an AA battery with a jigga watt charger and cry you should have used a regulator.
The rubber caps under the plastic covers will pop off the agm battery when it gets overcharged. I had an old dead sealed lead acid battery and tried to overcharge it directly from the panel. It popped and boiled off the liquid inside. Your right, you have to have a regulator to charge with an unattended battery.
My unregulated 4.5w is keeping my battery above 15v all the time. It starts the car like a champ. When can I expect the 17 year old battery to be ruined? Before I added the panel, the battery was on its last legs and struggling to start the car. Now, it works like new. I checked with my hand, the battery was not warm. I didn't expect it to be since the non-optimally placed panel only pumps in around 60mA in bright sun. The sleeping car draws 20-30mA.
What do you mean with the 5.5% capacity at minute 4:20? What has W to do with Ah? In my opinion the 12W Solar cell does not have any capacity! But the 0.8A current is only 0.36% of the 220Ah capacity of the battery. I think it should be better to compare the same unit!
What causes it to be ... like when the sun goes down and suddenly the battery bank voltage is dropping to below 12 Volts, but the rest of the time it seems fine? The voltage I'm getting on a battery bank is too low for new batteries. But I've been careful charging them and careful with the equipment. I don't understand why I'm getting such low voltage though...
Won't push current til 17.2v is cleared, possibly 21.6v because it's shorted straight to the battery, the battery doesn't just turn it to amps when under source voltage. Probably less charged when you disconnect the solar panel and check the voltage, a inverter might like it though.
What voltage output is the solar panel? It looked like the sticker said 17.2 Voc to "21.6"Vmp volts. So, yeah, it's going to try to charge that "12" volt battery closer to 18 volts.
I can’t read it on my phone but 12V panels will usually make 19V. My epever mppt is showing 20V 11.2A from the panels right now and the battery is showing 14.4 with 10.1A of charging input currently. But I can’t read the tag on the panel in the video so I can’t confirm that the label is showing open circuit voltage or not. (Mppt takes full available voltage/current from the panels and delves it out accordingly. In my case I ‘could’ wire the panels 24V and it would still deliver to the battery bank appropriately.) My favorite PWM charge controller is a P30L and that is going on my boat. At ~$40 it’s ‘expensive’ compared to others but it has worked excellent over time, equalizes the batteries on a sched, and offers a great interface with performance data logging. It’s worth the extra pizza in price because I know it works and lasts. That’s a great boat charge controller although I don’t think it is “marine” rated. And definitely cheaper than new batteries!
Charging at 15.1 volts is only .4 volts above normal. Most smart chargers will produce up to 16.2 volts to condition the battery then tapper off to 14.4-14.6 volts then float at 95% charge.
I do this all the time an it just worked fine - 160 watt panel - up to 8 amps into battery at 20 volt, and disconnect at 15.3 volt, on a daily basis - kind regards - Ben
Reading the voltage whilst under charge will give you the charge voltage and not the actual battery voltage. To do so, you would need to remove the panel and simply test the batteries. I very much doubt you would find such a large capacity battery taking on sub 1amp charge any where near the 15volts you measured. This is also why the second single battery showed the same voltage. It wasn't increasing the batteries charge rather than showing the input coming from the panel. deep cycle batteries dishcharge at a rat of approx 3% per month . So you are right that saying a panel at 10% the battery capacity MAY still result in an over charge if left idle for long enough. Of course it wont be applying charge for more than 6-8 hours at most and that is with perfect weather, every day for an extended period , which is highly unlikey but still possible.
And then there are the famous Volkswagen solar "float" chargers. They output about 5 watts, and are designed to be continuously connected. The older design plugged into a cigar lighter socket, and had no form of regulation. The newer version has a charge controller, which appears to limit the voltage to about 14 volts, as opposed to the much higher voltage from the older model. Once upon a time I used one of the older panels to recharge a sealed lead acid 5 Ah battery, which seemed to work OK, but I never left the panel connected more than about 5 or 6 hours at a time.
My understanding about deep cycle batteries is even if you charged with a regulated solar system, if your not using 7-15 amps your damaging the battery. 2 amps with over charging protection still damages batteries. DEep cycle
Who ever told you that you do not need a regulator is probably the type of person who does things half-fast. They are the people who don't do anything reliably. In this case it is also unsafe. The only good thing about their advice is that it keeps battery companies in business making new batteries to replace the ones they ruined. I personally hate to damage things by overcharging because then I get to pay more money that I otherwise never would had to if I had just bought the controller.
+pearlmax Gentlemen use "half-fast" as a cute pun without being rude. It used to one on signs in diners. It read "The cook isn't fast or slow, she's half-fast". I thought everyone knew that joke.
It amazes me that people aren't willing to spend $10-$20 for a charge controller. A basic Harbor Freight controller will do the trick, even with lifepo4 cells. It's not as efficient as MPPT but if you're just trying to maintain float - why not just invest a tiny bit more money into something that'll protect it? If the solar panel manufacturers say to use a controller for batteries - you should.
I can get a controller cheap but won't. Instead, I analyse and know my 4.5w panel is only producing 0.9w behind the car glass. Since over charging is not possible, I don't blindly go buy a regulator like a dumbo.
i would like to point out that indeed a lot of chargers wil do bulk and absorbtion till 14.4 volt....this is for most AGM and CALCIUM plate batteries actualy to low of a voltage causing sulfation because the batterie is only charged to 95 percent each cycle, the better chargers ( victron marine and others) have a special " high" setting nowedayse on, taking the voltage up to 14,8 during bulk and absorbsion....even then its adviseble to do, say once a month to " recondition" the batterys with a controlled overload to 15,5 to 16 volts with low amps during MAX one hour! this will ensure two things, it wil " equalyze the cells and charge really till 100 percent to get rid of sulvation! actualy the real charging voltage of a lead acid battery is 15.2 volts but since this is dependend on temperature and age( quality) of the battery most chargers manufacturers wil keep voltage at the lower and saver 14,4 value, thus avoiding consumer claims of blown batterys, that and undercharging is the reasen many battery banks dy prematurly due to sulvation
I have an 800 watt Renogy system that has a charge controller. It is a 24 volt system. Can anyone recommend some kind of monitors that I could buy so I can monitor the batteries, how much is going in and out, how much they are charged, etc.? Thanks
Aren't you supposed to equalize flooded batteries? Copied from the Crown CR220 spec sheet... Phase 3: Constant Current = 5.0 amps or approximate. (Phase 3 is the equalization charge.) Normal transition to END OF CHARGE at 115 - 118% of AH returned. Recommended Equalization Charge: Every seven (7) days. 4 additional hours at normal finish rate of 5.0 amps. So the equalization charge for the EverStart should be about 2.5 amps. Someone isn't reading the manufacturer's spec sheet correctly. And if you look up the specs for your Lifeline batteries, the absorption voltage is 15.31 volts at 20ºC and you are at 15.13 volts. From the spec sheet... Charging Lifeline® AGM batteries is a matter of replacing the energy removed during discharge plus a little extra to make up for charging inefficiency. The amount of energy necessary for complete recharge depends on the depth of discharge, rate of recharge, and temperature. Typically, between 102% and 110% of the discharged ampere-hours must be returned for full recharge. They even have a special conditioning charge for when you neglect to fully charge the battery. This is for the 220 AH AGM battery and at 20ºC, the voltage required is 16.48 volts and a current of about 4 amps. And you're mucking about with 0.73 amps?
Tell your customers that a can't BELIEVE EVERYTHING they see on U-Tube. All Solar Panel need a Charge Controller, if you don't YOU'LL PAY THE PRICE......
yeah that walmart battery is crap thats why they don't sell it anymore. I know I had three of them they were shit. Also note the minus 15 you have the wires crossed. Pay attention to what your'e doing.
the point seems to be you can damage a battery you already had fully charged, by overcharging it with a solar panel. Truly a revelation. Now what if instead of charging that battery for a week you had actually used it like real people do, leaving the battery 50% depleted?
+kiskiller3 only if you actually overcharged it and werent using the devices hooked up to it daily. In the real world, people that live in their vehicles/rvs and add a solar panel have a second battery in a state of constant depletion and each and every day use far more power than the panel produces. If you were going to park it for an extended period you can put a cutoff switch inline.
+FuckGoogle+ it still is a very bad practice. And in the real world thousands of batteries are damaged every year because of overcharging, i routinely replace hundreds of batteries every month and they mostly die because of overcharging.
+kiskiller3 Isn't it just an assumption they died from overcharging? AGM deep cycle batteries are also at risk from being in a state of constant depletion are they not? If you have a vehicle with a 12v freezer in it that draws 5a when running, and runs 12 hours or more per day, day in and day out, and have a 10-12w panel hooked up to the (large) battery that runs it, there is no possible way that battery could ever reach an overcharged state. Let alone if you added additional devices. (I have a Deka/Alcatel 145ah AGM deep cycle data battery in this situation) Killed the first one in a year due to depletion.
yes in this case if the load is always more than what the panel generates the battery will never get overcharged but most of the time a load is not always drawing current so this is why you need charge controller even if you have a load on the battery. Yes the batteries did die because of overcharging as they where held at 14.7 volts for a couple of years. this issue is common in UPS battery backup applications.
So, hooking up a panel with an unloaded output voltage of (likely) 17-21 volts causes your voltmeter across the battery and panel to show a reading more than 12.7 volts? Isn't this what we would expect to observe? Bottom-line, don't leave a source charging voltage of more than about 13-14 volts on a battery bank for an indefinite time. This is elementary. BTW, the rated watt (availability) of the panel is mostly irrelevant; it's the relatively high terminal voltage of the panel that matters.
You'e 100% right about shoving from 18 volt to 24 volt of raw power into 12 volt battery. From Amazon, the dash 12 volt 10 watt solar panel, from panel to DC clamp and or to cigarette light plug. The reviews is pretty poorly.
this video is just showing what can happen if you do it improperly. it's not saying don't use a solar panel, it's saying make sure you get the right voltage panel for the battery and/or use proper protection (eg, a charge controller)
+Josh Law Josh a CC (constant current) charge of 1A left continuously can eventually raise the voltage of the battery to damaging levels, especially AGM batteries which have very low self discharge.. This 12W panel is really only capable of about 0.6A to 0.7A and it can clearly be seen what happens when the panel is left connected to the point where the battery becomes chock full. Batteries are floated at CV or constant voltage, not constant current unless you are using a CC/CV/CC charger for short duration industrial applications. For a marine or solar application our chargers and controllers are; CC/Bulk > CV Absorption > CV Float or CC>CV>CV charging. If we use the DIN definition I>Uo>U.. As for brain damaged you may want to comprehend batteries, charging and the difference between CC and CV charging a bit better before leaving nasty comments.
+CompassMarine also the 0.6 A after losses basically become 0. 4 A. That's kinda good to keep battery on long term charging. I was thinking maybe folks who go on long term vacation could hook up their car batteries to a low power panel so it would compensate for the discharge.
It's his battery and he can do what he wants. It's educational for others. In any case, he's measuring the voltage of the panel. It doesn't mean the battery is taking in charge. As the battery becomes full, it would resist charging. The small panel may not have the power to counter the resistance. When I charge my battery from the wall. The measured voltage across the posts is 16V. It doesn't mean the battery is damaged. It is quite normal.
Do you think an inexpensive charge controller like the $30 "Battery Tender" Solar Controller can regulate a small 7 watt solar panel similar to the one you are testing in this video? This Charge Controller claims it can regulate 5-45 watts. Here is the controller I ordered... www.amazon.com/gp/product/B004Q820UK/ref=ppx_yo_dt_b_asin_image_o04_s00?ie=UTF8&psc=1
a good demo and good advice, I am an electrical engineer, you can trust this video
Can't trust anyone who charges a fully charged battery. Why would anyone do that? In a typical scenario where a solar panel is used, such as on a car or boat, there is usually a draw on the battery. The solar panel should then be correctly sized to compensate for the draw and self-discharge, resulting in a small overall drain or gain that isn't going to produce much harm. Small panels sold in retail are usually deliberately under powered, and there's no risk of harm for the intended purpose. Also, as the battery becomes full, it would resist charging. Small panels don't have the power to over come that resistance. It's all about being appropriate. You don't be charging an AA battery with a jigga watt charger and cry you should have used a regulator.
The rubber caps under the plastic covers will pop off the agm battery when it gets overcharged. I had an old dead sealed lead acid battery and tried to overcharge it directly from the panel. It popped and boiled off the liquid inside. Your right, you have to have a regulator to charge with an unattended battery.
My unregulated 4.5w is keeping my battery above 15v all the time. It starts the car like a champ. When can I expect the 17 year old battery to be ruined? Before I added the panel, the battery was on its last legs and struggling to start the car. Now, it works like new. I checked with my hand, the battery was not warm. I didn't expect it to be since the non-optimally placed panel only pumps in around 60mA in bright sun. The sleeping car draws 20-30mA.
What do you mean with the 5.5% capacity at minute 4:20? What has W to do with Ah? In my opinion the 12W Solar cell does not have any capacity! But the 0.8A current is only 0.36% of the 220Ah capacity of the battery. I think it should be better to compare the same unit!
Weed Amp Hours
You should look into charge voltages and battery temps.... there's a huge swing and it mattery
Will a 24 volt battery bank wiring setup last longer than a 12 volt battery bank setup?
So how do I find out what watt and voltage rating solar panel I need with what charge controller for a "12v" 35Ah AGM battery?
With FLA, SLA, fork lift batteries that 15v is ok for desulfation once every few months but even then you want a good charge controller to do that.
What causes it to be ... like when the sun goes down and suddenly the battery bank voltage is dropping to below 12 Volts, but the rest of the time it seems fine? The voltage I'm getting on a battery bank is too low for new batteries. But I've been careful charging them and careful with the equipment. I don't understand why I'm getting such low voltage though...
Won't push current til 17.2v is cleared, possibly 21.6v because it's shorted straight to the battery, the battery doesn't just turn it to amps when under source voltage. Probably less charged when you disconnect the solar panel and check the voltage, a inverter might like it though.
What voltage output is the solar panel? It looked like the sticker said 17.2 Voc to "21.6"Vmp volts. So, yeah, it's going to try to charge that "12" volt battery closer to 18 volts.
I can’t read it on my phone but 12V panels will usually make 19V. My epever mppt is showing 20V 11.2A from the panels right now and the battery is showing 14.4 with 10.1A of charging input currently.
But I can’t read the tag on the panel in the video so I can’t confirm that the label is showing open circuit voltage or not.
(Mppt takes full available voltage/current from the panels and delves it out accordingly. In my case I ‘could’ wire the panels 24V and it would still deliver to the battery bank appropriately.)
My favorite PWM charge controller is a P30L and that is going on my boat. At ~$40 it’s ‘expensive’ compared to others but it has worked excellent over time, equalizes the batteries on a sched, and offers a great interface with performance data logging. It’s worth the extra pizza in price because I know it works and lasts. That’s a great boat charge controller although I don’t think it is “marine” rated. And definitely cheaper than new batteries!
excellent information!Thank You for this posting!!!
Shouldn't your amp meter be on the negative?
How about pulse charging can this also damage the batteries?
i have a lucas 22ah agm. will it explode or just vent and lose capacity?
Charging at 15.1 volts is only .4 volts above normal. Most smart chargers will produce up to 16.2 volts to condition the battery then tapper off to 14.4-14.6 volts then float at 95% charge.
Ideal float is 13.20, 15v is only to stress the flooded battery to ecualizate a battery bank each month.
@@jhonmorenocastro3010 float is between 13.2-13.8 depending on temp of battery.
What is an acceptable voltage for a fully charged batteries of these types ?
14.8 volts max, more like 14.5
I do this all the time an it just worked fine - 160 watt panel - up to 8 amps into battery at 20 volt, and disconnect at 15.3 volt, on a daily basis - kind regards - Ben
Can i have that overcharged battery you got there thanks
Great info, thanks!
Thanks for the info.
Reading the voltage whilst under charge will give you the charge voltage and not the actual battery voltage. To do so, you would need to remove the panel and simply test the batteries.
I very much doubt you would find such a large capacity battery taking on sub 1amp charge any where near the 15volts you measured.
This is also why the second single battery showed the same voltage. It wasn't increasing the batteries charge rather than showing the input coming from the panel.
deep cycle batteries dishcharge at a rat of approx 3% per month .
So you are right that saying a panel at 10% the battery capacity MAY still result in an over charge if left idle for long enough.
Of course it wont be applying charge for more than 6-8 hours at most and that is with perfect weather, every day for an extended period , which is highly unlikey but still possible.
And then there are the famous Volkswagen solar "float" chargers. They output about 5 watts, and are designed to be continuously connected. The older design plugged into a cigar lighter socket, and had no form of regulation. The newer version has a charge controller, which appears to limit the voltage to about 14 volts, as opposed to the much higher voltage from the older model.
Once upon a time I used one of the older panels to recharge a sealed lead acid 5 Ah battery, which seemed to work OK, but I never left the panel connected more than about 5 or 6 hours at a time.
So true thank you
My understanding about deep cycle batteries is even if you charged with a regulated solar system, if your not using 7-15 amps your damaging the battery. 2 amps with over charging protection still damages batteries. DEep cycle
is a 30W panel too much for a Group27DC with a controller?
It's okay if you have a decent charge controller.
Your 12V panel has a current rating of about 1amp. So that's only 0.45% of the 220 AH battery rating.
Interesting. good video
Who ever told you that you do not need a regulator is probably the type of person who does things half-fast. They are the people who don't do anything reliably. In this case it is also unsafe. The only good thing about their advice is that it keeps battery companies in business making new batteries to replace the ones they ruined. I personally hate to damage things by overcharging because then I get to pay more money that I otherwise never would had to if I had just bought the controller.
How will a 12w panel overload the batteries? It will just provide the batteries with a float charge
+John Doe The term is half-assed, not half-fast.
+pearlmax he musta bought a half ass slang dictionary.
FuckGoogle+ hahaha!! Yeah, from a lesser known publisher.
+pearlmax Gentlemen use "half-fast" as a cute pun without being rude. It used to one on signs in diners. It read "The cook isn't fast or slow, she's half-fast". I thought everyone knew that joke.
It amazes me that people aren't willing to spend $10-$20 for a charge controller. A basic Harbor Freight controller will do the trick, even with lifepo4 cells. It's not as efficient as MPPT but if you're just trying to maintain float - why not just invest a tiny bit more money into something that'll protect it? If the solar panel manufacturers say to use a controller for batteries - you should.
I can get a controller cheap but won't. Instead, I analyse and know my 4.5w panel is only producing 0.9w behind the car glass. Since over charging is not possible, I don't blindly go buy a regulator like a dumbo.
Your polarity is reversed on the Everstart
i would like to point out that indeed a lot of chargers wil do bulk and absorbtion till 14.4 volt....this is for most AGM and CALCIUM plate batteries actualy to low of a voltage causing sulfation because the batterie is only charged to 95 percent each cycle, the better chargers ( victron marine and others) have a special " high" setting nowedayse on, taking the voltage up to 14,8 during bulk and absorbsion....even then its adviseble to do, say once a month to " recondition" the batterys with a controlled overload to 15,5 to 16 volts with low amps during MAX one hour!
this will ensure two things, it wil " equalyze the cells and charge really till 100 percent to get rid of sulvation!
actualy the real charging voltage of a lead acid battery is 15.2 volts but since this is dependend on temperature and age( quality) of the battery most chargers manufacturers wil keep voltage at the lower and saver 14,4 value, thus avoiding consumer claims of blown batterys, that and undercharging is the reasen many battery banks dy prematurly due to sulvation
hey that a 21v solar panel it will definitely over charge the battery 12w does not matter
Small 12 volt solar panel usually put out 18 volts from back of panel.
I have an 800 watt Renogy system that has a charge controller. It is a 24 volt system.
Can anyone recommend some kind of monitors that I could buy so I can monitor the batteries, how much is going in and out, how much they are charged, etc.?
Thanks
Aren't you supposed to equalize flooded batteries? Copied from the Crown CR220 spec sheet... Phase 3: Constant Current = 5.0 amps or approximate. (Phase 3 is the equalization charge.)
Normal transition to END OF CHARGE at 115 - 118% of AH returned.
Recommended Equalization Charge: Every seven (7) days. 4 additional hours at normal finish rate of 5.0 amps.
So the equalization charge for the EverStart should be about 2.5 amps. Someone isn't reading the manufacturer's spec sheet correctly.
And if you look up the specs for your Lifeline batteries, the absorption voltage is 15.31 volts at 20ºC and you are at 15.13 volts.
From the spec sheet... Charging Lifeline® AGM batteries is a matter of replacing the energy removed during discharge plus a little extra to make up for charging inefficiency. The amount of energy necessary for complete recharge depends on the depth of discharge, rate of recharge, and temperature. Typically, between 102% and 110% of the discharged ampere-hours must be returned for full recharge.
They even have a special conditioning charge for when you neglect to fully charge the battery. This is for the 220 AH AGM battery and at 20ºC, the voltage required is 16.48 volts and a current of about 4 amps. And you're mucking about with 0.73 amps?
This would have been more convincing if you removed the solar panel and allowed us to watch the voltage of the battery.
Tell your customers that a can't BELIEVE EVERYTHING they see on U-Tube. All Solar Panel need a Charge Controller, if you don't YOU'LL PAY THE PRICE......
yeah that walmart battery is crap thats why they don't sell it anymore. I know I had three of them they were shit. Also note the minus 15 you have the wires crossed. Pay attention to what your'e doing.
THAT IS WHAT I THOUGHT ALSO
Who cares about that? It is the voltage we are concerned about, not the direction of flow the meter is reading.
the point seems to be you can damage a battery you already had fully charged, by overcharging it with a solar panel.
Truly a revelation.
Now what if instead of charging that battery for a week you had actually used it like real people do, leaving the battery 50% depleted?
+FuckGoogle+it would eventually reach a fully charged state and then the battery would get damaged anyway.
+kiskiller3 only if you actually overcharged it and werent using the devices hooked up to it daily.
In the real world, people that live in their vehicles/rvs and add a solar panel have a second battery in a state of constant depletion and each and every day use far more power than the panel produces. If you were going to park it for an extended period you can put a cutoff switch inline.
+FuckGoogle+ it still is a very bad practice. And in the real world thousands of batteries are damaged every year because of overcharging, i routinely replace hundreds of batteries every month and they mostly die because of overcharging.
+kiskiller3 Isn't it just an assumption they died from overcharging? AGM deep cycle batteries are also at risk from being in a state of constant depletion are they not?
If you have a vehicle with a 12v freezer in it that draws 5a when running, and runs 12 hours or more per day, day in and day out, and have a 10-12w panel hooked up to the (large) battery that runs it, there is no possible way that battery could ever reach an overcharged state. Let alone if you added additional devices.
(I have a Deka/Alcatel 145ah AGM deep cycle data battery in this situation)
Killed the first one in a year due to depletion.
yes in this case if the load is always more than what the panel generates the battery will never get overcharged but most of the time a load is not always drawing current so this is why you need charge controller even if you have a load on the battery. Yes the batteries did die because of overcharging as they where held at 14.7 volts for a couple of years. this issue is common in UPS battery backup applications.
So, hooking up a panel with an unloaded output voltage of (likely) 17-21 volts causes your voltmeter across the battery and panel to show a reading more than 12.7 volts? Isn't this what we would expect to observe? Bottom-line, don't leave a source charging voltage of more than about 13-14 volts on a battery bank for an indefinite time. This is elementary. BTW, the rated watt (availability) of the panel is mostly irrelevant; it's the relatively high terminal voltage of the panel that matters.
the panel must put out some amperage in order to be able to raise the voltage of the battery that much.
You'e 100% right about shoving from 18 volt to 24 volt of raw power into 12 volt battery. From Amazon, the dash 12 volt 10 watt solar panel, from panel to DC clamp and or to cigarette light plug. The reviews is pretty poorly.
wow, and I was going to buy a solar charging panel too, well, I'm turned off from it.
this video is just showing what can happen if you do it improperly. it's not saying don't use a solar panel, it's saying make sure you get the right voltage panel for the battery and/or use proper protection (eg, a charge controller)
Sorry. But I still don't think a 12w panel will damage such huge batteries
Billy Carvalhoit will on long term
+Josh Law batteries need to be charged at a regulated voltage
+Josh Law Josh a CC (constant current) charge of 1A left continuously can eventually raise the voltage of the battery to damaging levels, especially AGM batteries which have very low self discharge.. This 12W panel is really only capable of about 0.6A to 0.7A and it can clearly be seen what happens when the panel is left connected to the point where the battery becomes chock full. Batteries are floated at CV or constant voltage, not constant current unless you are using a CC/CV/CC charger for short duration industrial applications. For a marine or solar application our chargers and controllers are; CC/Bulk > CV Absorption > CV Float or CC>CV>CV charging. If we use the DIN definition I>Uo>U..
As for brain damaged you may want to comprehend batteries, charging and the difference between CC and CV charging a bit better before leaving nasty comments.
+CompassMarine also the 0.6 A after losses basically become 0. 4 A. That's kinda good to keep battery on long term charging. I was thinking maybe folks who go on long term vacation could hook up their car batteries to a low power panel so it would compensate for the discharge.
+CompassMarine right or wrong, Billy C stating his disagreement hardly qualifies as a "nasty comment"
I am careful, why i don"t listen to you...
Yy
Get more batteries 😕 or go lit
It was not true.
Your battery is dead already.
If you ve seen the voltage its higher, why you charge it like that for few days? You damage your batteries to show on youtube? You must be sick.
It's his battery and he can do what he wants. It's educational for others. In any case, he's measuring the voltage of the panel. It doesn't mean the battery is taking in charge. As the battery becomes full, it would resist charging. The small panel may not have the power to counter the resistance. When I charge my battery from the wall. The measured voltage across the posts is 16V. It doesn't mean the battery is damaged. It is quite normal.
Do you think an inexpensive charge controller like the $30 "Battery Tender" Solar Controller can regulate a small 7 watt solar panel similar to the one you are testing in this video? This Charge Controller claims it can regulate 5-45 watts. Here is the controller I ordered... www.amazon.com/gp/product/B004Q820UK/ref=ppx_yo_dt_b_asin_image_o04_s00?ie=UTF8&psc=1