I just spent $210 AGM battery for my Ford focus. It lasted almost 5 years. I has a 10 year old Dodge with the original acid battery in it before this car. So I guess AGM costs twice as much and lasts half as long. It's kinda like the florescent spiral light bulbs that were supposed to last 20 years that needed replacing every 6 months.
Thank You Jeff for all your informative and well narrated videos. Question, How do you monitor your AGM batteries to know at what %age they are? Thanks in Advance.
The best, and arguable only way to know the condition and health of any deep cycle use battery is to do a c20 battery test. That will give you an exact AH value of the batteries which you can compare to the sticker value. If the sticker says 100ah and the test gives you 90ah. the battery is 90% good. On boats I would replace a battery under 80%. The test could be done every 1-2 years or if you think they have problems. Once you test them you can then reset your battery monitor to that test value which will allow it to give correct info. See c20 battery test info www.pysystems.ca/resources/boating-tech-talk/geoff-measure-battery-capacity/
With AGM batteries is there between a battery that is used as a starting battery as apposed to an AGM that is used for the hotel load? Your videos are a great resource. Thanks to everyone at PYS for their effort.
Most AGM batteries are good at both engine starting and house loads. Some battery manufacturers, like NorthStar, now have AGM batteries with high cranking amps.
My problem is the weight. I don’t have space for inspection or room to add fluid and they are to heavy to move once per month. I had to go with 2 100AH AGM. That equates to 100AH of usable charge. The necessities of being a CPAP user.
If you want to have a great number of recharge cycles then I would suggest to read the battery manual and see how your recharge cycles deminish when going lower then 50 percent
Hi Jeff, nicely shared! I remember you said that we can parallel two or more identical battery charger in order to increase and maximize the charge of the battery bank. I haven’t found detailed infos about how to wire such two battery charger in parallel. Can you tell? Many thanks.
Good Morning Jeff, If you could point me in the correct direction on my question I would appreciate it, I have twin engines with high amp alternators (150 ea) 1 house battery bank (4 agms) 1 engine battery (31). Should I used a battery combiner to connect both alternators to both battery banks, or use a battery isolator for both banks and connect the alternators to it, or connect 1 alternator to the house bank and the other to the engine bank. Thanks Jeff Allen
Hi Allen, you already have large alternators. Simplest solution is to connect each alternator to it's own battery bank. One solution is to have the one alternator directly connected to the house battery and the other alternator connected to a battery isolator in turn connected to house and engine battery.
@@PacificYachtSystems Thank you Jeff for your input, this is a Cruise a Home built in 1976 in Everett Washington and they did use Romex for the AC. I really want to replace it but can't see removing all the interior so I will be looking for those ghosts you talk about. Thanks
Hi Jeff, loving the new series! I was wondering what the best way to join 2 cables in to 1 in the most safe and waterproof way. Something like where you would have 2 nav lights in parallel of a single feed from the helm. Thank you
@@PacificYachtSystems so a butt connector can be used to make a Y connection where a single wire feeds 2 lights as long as glue lined heat shrink is used?
Great video. By the way does high temperature above 100 F 0r below zero F causes any damage to AGM battery? And if so what is the best way to protect them in a Travel Trailer?
Good question, to my knowledge all batteries have a safe temperature operating zone, and any operation beyond this range will affect performance. Besides temp control, like a heating blanket, not sure how you protect a battery beyond the recommend operating range.
Hi Jeff William here. I love your content. I have a 36 volt golf cart. With 6, 6 volt lead acid batteries. 1 battery is brand new 3 weeks old. Just pulled all of my batteries out of the golf cart to clean the acid off of the battery tray. So that it will mot corrode. When doing so I noticed that the the 5 older batteries from 2013 are no longer square. They are swollen on the sides. They still function for now. Thinking about just changing them out proactively to AGM. So I would just replace the 6 batteries with 3, 12 volt AGM batteries. Is that correct? Also would I still charge the batteries with my 36 volt charger that comes with the golf cart?
Good observation, swollen batteries aren't a good sign. As you mentioned, consider replacing batteries sooner rather then later. You can get to 36 volts by wiring 3 12 volt batteries in series.
Hi Jeff. Great video. What's the difference between a gel cell battery and an AGM? Which has the most life cycles and what's the depth of discharge differences between the two? And is charging the batteries the same process? Thanks!
@@PacificYachtSystems Thanks for the reply. I thought there was a consideration for breaker use vs fuse. Are you saying breakers and fuses should be the same rating for a given circuit?
Do the AGMs give 20% more or 40% more? The way I score it to compare the two types of batteries, the AGMs give 40% more amp-hours than an equivalently rated flooded battery.
With AGM, you can trade-off battery cycles to go deeper on the discharge. Some boaters , discharge their AGM batteries to about 30% of capacity versus 50% of capacity for flooded lead acid. Since the bulk charge ceiling is at 85% for AGM and flooded lead acid (FLA), useable is 55% for AGM and 35% for FLA.
@@PacificYachtSystems I haven't bought my lead-acid batteries yet so I want to compare the amount of usable energy (in Ah) that I can get out of each type.. If we have an AGM and a FLA that are each nominally 100Ah, and we anticipate staying in the bulk charging range, then the AGM provides 55Ah and the FLA provides 35Ah. Which means that the AGM provides 1.57 times (55Ah/35Ah) more Ah than the FLA - or 57% more.. If the batteries are being used where they are usually topped off, then the AGM provides 70Ah and the FLA 50 Ah, so in that use scenario (70Ah/50Ah), the AGM provides 1.40 times more Ah than the FLA, or 40% more. I'm glad I asked, because you made it clearer to me that when in the bulk charging range, the AGMs have a very strong advantage. Great stuff! Thanks!
Hi Jeff, could you perhaps do an instructional on crimping battery lugs and torquing of terminal bolts and whether to coat them with anything etc or not.. or one on setting up solar controllers charge parameter voltages.. Regards Stormer
When I've discharged my AGM (L16) house batteries to anywhere near 50% SOC the voltage reads about 12.1VDC. If I were to take the bank down to 30% SOC, for example, wouldn't voltage drop dangerously low to 11.8 range? Or maybe (once or twice a season) 11.8 isn't so bad? What say you Jeff!
Hi Richard, that's correct, a lead acid battery will drop voltage over time. Choosing to go lower then 12 volts is a choice, and if you have AGM batteries you can do so once in a while, knowing that the lower the battery voltage goes you also in turn reduce the number of battery cycles.
Hi Jeff, with all these 200ah and 300ah batteries on the market, does it make any sense to buy a 100ah marine grade battery anymore these days ? I look forward to hearing back from you.
Good question. When sizing a battery bank, we generally try to keep the number of batteries' to a minimum. If redundancy is important to the boater, we'll sometimes, build a battery bank with at least two batteries in parallel, so if one battery fails it can be isolated.
I been off grid 3yrs I was about to get 2 trogen t105 for $159 each with cores He sent me a message saying he had 2 agm batteries reconditioned $75 each straight out no core I like to know what you think?
Hmmm, hard to quantify what does "reconditioned" mean? Is the battery 50% or 75% of capacity. It's a tough call to buy used batteries as you don't know how the batteries got abused.
AGM does not do well with a partial recharges correct? Say you start off 100%, underway drop to 80% after short cruise with loads, then shut down overnight at anchor, next time you start you only run for enough of maybe, let’s say 5% recharge, and keep repeating so as to only ever get around 70%-80% while out of your boat slip/shore power top-off, …Up and down from less than full charge shortens the battery’s life, even if you never drop below 30-50% DOD?
To keep a long battery life with AGM, they should be periodically recharged to 100%. From experience, many AGM batteries seem to have shorter lives when left in a partial state of discharge for long periods of time.
If you already have AGMs, use them up before replacing, but don't play games, these days LiFePo4 is the ONLY chemistry to consider. Even if the outlay is twice that of any other common chemistry, which it is, the cost in and out over time is dirt cheap, compared. Underspec the battery if you are forced to, but do LiFePo4. :)
I don’t actually agree. I’ve just been through this decision process. Before we started I was absolutely convinced I was going to swap my old flooded lead acid to lithium. But as we started to look at the impact of switching to LifePo4 on all our systems (winches, bow thruster, windlass, and alternator) the additional costs were rapidly approaching the of the cost of the lithium batteries themselves, doubling the total cost. So suddenly the ROI calculation changes. In the end I swapped our 3 x 140 flooded lead acid to 4 x 170 of the latest super cycle Victron AGMs. Using Jeff’s suggestion of 70% DOD that means I could go to 476 ah, more than I was going to get under Lithium and at a minimum of a quarter of the price. At the cost I could replace them 3 or 4 times over (15-20 years?) and still be about the same total cost of switching to LifePo4. To be clear, I’m not dismissing lifepo4 in the longer term, but our boat isn’t ready for the switch yet. Maybe in 5-7 years time I will have made a number of upgrades, the cost of the lifepo4 batteries will have dropped further and the technologies will have matured more, then I can look again. Or maybe there will be something even better. Until then I’m really happy that I made the right choice for our boat.
@@petergibson6563 Are you a pro? I’m not so I can only say that the views I got on this topic varied. Depending on the battery manufacturer, there is a risk that the Lifepo4 BMS will shutdown during very high current loads like bow thrusters, windlass or winches if the current exceeds the manufacturer’s threshold. That’s a risk I don’t want. Then there was the complexity of dual charging different chemistries via the alternator. Again opinions differed and again I didn’t want to take the risk of trying different solutions.
Hi Tom, my advice to fellow boaters is there is no perfect battery for everyone. Lithium is a strong contender for boaters that need the most energy density out of a battery bank. If space and weight is really important to you, then Lithium makes lots of sense. Also if you plan on using your battery bank extensively, like a liveaboard and you'll be cycling the battery thousands of times over years to come, Lithium is a strong contender. All that said, Lithium does come with a price tag many boaters cannot afford. And NOT everyone needs the benefits of a Lithium battery.
I just spent $210 AGM battery for my Ford focus. It lasted almost 5 years. I has a 10 year old Dodge with the original acid battery in it before this car. So I guess AGM costs twice as much and lasts half as long. It's kinda like the florescent spiral light bulbs that were supposed to last 20 years that needed replacing every 6 months.
Thanks for sharing your experience with AGM?
Yes, great comparison ! It's true, AGMs don't last any longer than lead-acid batteries.
Thank you for your knowledge and your generosity. You have a new subscriber.
Great video! Thank you!!
Jeff is there any plans on doing some installation video’s? I really enjoy the content on your channel.
Thinking about it, but takes more time to set-up.
What agm battery brand do you recommend for use in golf carts? What about Optima as a choice and if so, which one?
Big fan of the Rolls and Victron AGM batteries.
Does AGM batteries require a special charge regulator unlike a lead acid battery that doesn’t, similar to that of a lithium battery?
Great video again Jeff, love the single question answer format it's brilliant many thanks Roy.
Glad you enjoyed it
Thank You Jeff for all your informative and well narrated videos. Question, How do you monitor your AGM batteries to know at what %age they are? Thanks in Advance.
The best, and arguable only way to know the condition and health of any deep cycle use battery is to do a c20 battery test. That will give you an exact AH value of the batteries which you can compare to the sticker value. If the sticker says 100ah and the test gives you 90ah. the battery is 90% good. On boats I would replace a battery under 80%. The test could be done every 1-2 years or if you think they have problems. Once you test them you can then reset your battery monitor to that test value which will allow it to give correct info.
See c20 battery test info
www.pysystems.ca/resources/boating-tech-talk/geoff-measure-battery-capacity/
Do you have a video taking about upgrading from flooded to AGM and the pitfalls associated with it ? Thanks
Good suggestion.
With AGM batteries is there between a battery that is used as a starting battery as apposed to an AGM that is used for the hotel load? Your videos are a great resource. Thanks to everyone at PYS for their effort.
Most AGM batteries are good at both engine starting and house loads. Some battery manufacturers, like NorthStar, now have AGM batteries with high cranking amps.
My problem is the weight. I don’t have space for inspection or room to add fluid and they are to heavy to move once per month. I had to go with 2 100AH AGM. That equates to 100AH of usable charge. The necessities of being a CPAP user.
If you want to have a great number of recharge cycles then I would suggest to read the battery manual and see how your recharge cycles deminish when going lower then 50 percent
Yep, diminishing returns the deeper you discharge a battery.
Hi Jeff, nicely shared!
I remember you said that we can parallel two or more identical battery charger in order to increase and maximize the charge of the battery bank. I haven’t found detailed infos about how to wire such two battery charger in parallel. Can you tell? Many thanks.
No trick to it, just connect both chargers to the same battery.
Good Morning Jeff, If you could point me in the correct direction on my question I would appreciate it, I have twin engines with high amp alternators (150 ea) 1 house battery bank (4 agms) 1 engine battery (31). Should I used a battery combiner to connect both alternators to both battery banks, or use a battery isolator for both banks and connect the alternators to it, or connect 1 alternator to the house bank and the other to the engine bank.
Thanks Jeff
Allen
Hi Allen, you already have large alternators. Simplest solution is to connect each alternator to it's own battery bank. One solution is to have the one alternator directly connected to the house battery and the other alternator connected to a battery isolator in turn connected to house and engine battery.
@@PacificYachtSystems Thank you Jeff for your input, this is a Cruise a Home built in 1976 in Everett Washington and they did use Romex for the AC. I really want to replace it but can't see removing all the interior so I will be looking for those ghosts you talk about. Thanks
Hi Jeff, loving the new series! I was wondering what the best way to join 2 cables in to 1 in the most safe and waterproof way. Something like where you would have 2 nav lights in parallel of a single feed from the helm. Thank you
You can use a butt connector, they even make it for 4/0 wiring, and use heat shrink over top of the connection point.
@@PacificYachtSystems so a butt connector can be used to make a Y connection where a single wire feeds 2 lights as long as glue lined heat shrink is used?
Great video. By the way does high temperature above 100 F 0r below zero F causes any damage to AGM battery? And if so what is the best way to protect them in a Travel Trailer?
Good question, to my knowledge all batteries have a safe temperature operating zone, and any operation beyond this range will affect performance. Besides temp control, like a heating blanket, not sure how you protect a battery beyond the recommend operating range.
Hi Jeff William here. I love your content. I have a 36 volt golf cart. With 6, 6 volt lead acid batteries. 1 battery is brand new 3 weeks old. Just pulled all of my batteries out of the golf cart to clean the acid off of the battery tray. So that it will mot corrode. When doing so I noticed that the the 5 older batteries from 2013 are no longer square. They are swollen on the sides. They still function for now. Thinking about just changing them out proactively to AGM. So I would just replace the 6 batteries with 3, 12 volt AGM batteries. Is that correct? Also would I still charge the batteries with my 36 volt charger that comes with the golf cart?
Good observation, swollen batteries aren't a good sign. As you mentioned, consider replacing batteries sooner rather then later. You can get to 36 volts by wiring 3 12 volt batteries in series.
Hi Jeff. Great video. What's the difference between a gel cell battery and an AGM? Which has the most life cycles and what's the depth of discharge differences between the two? And is charging the batteries the same process? Thanks!
Hi Jason, check out our articles on the pysystems.ca website and you'll find the answer there.
@@PacificYachtSystems Okay, great. Thanks!
Question: How do I size breakers and fuses for a given load?
Hi Chip, you take in consideration, the wire size connected to the breaker and also the circuit breaker specification from the manufacturer.
@@PacificYachtSystems Thanks for the reply. I thought there was a consideration for breaker use vs fuse. Are you saying breakers and fuses should be the same rating for a given circuit?
Do the AGMs give 20% more or 40% more? The way I score it to compare the two types of batteries, the AGMs give 40% more amp-hours than an equivalently rated flooded battery.
With AGM, you can trade-off battery cycles to go deeper on the discharge. Some boaters , discharge their AGM batteries to about 30% of capacity versus 50% of capacity for flooded lead acid. Since the bulk charge ceiling is at 85% for AGM and flooded lead acid (FLA), useable is 55% for AGM and 35% for FLA.
@@PacificYachtSystems I haven't bought my lead-acid batteries yet so I want to compare the amount of usable energy (in Ah) that I can get out of each type.. If we have an AGM and a FLA that are each nominally 100Ah, and we anticipate staying in the bulk charging range, then the AGM provides 55Ah and the FLA provides 35Ah. Which means that the AGM provides 1.57 times (55Ah/35Ah) more Ah than the FLA - or 57% more.. If the batteries are being used where they are usually topped off, then the AGM provides 70Ah and the FLA 50 Ah, so in that use scenario (70Ah/50Ah), the AGM provides 1.40 times more Ah than the FLA, or 40% more. I'm glad I asked, because you made it clearer to me that when in the bulk charging range, the AGMs have a very strong advantage. Great stuff! Thanks!
Hi Jeff, could you perhaps do an instructional on crimping battery lugs and torquing of terminal bolts and whether to coat them with anything etc or not.. or one on setting up solar controllers charge parameter voltages.. Regards Stormer
Hi Stormer, we do have those videos already uploaded, look for DIY series under our channel.
@@PacificYachtSystems I'll have a look thanks
When I've discharged my AGM (L16) house batteries to anywhere near 50% SOC the voltage reads about 12.1VDC. If I were to take the bank down to 30% SOC, for example, wouldn't voltage drop dangerously low to 11.8 range? Or maybe (once or twice a season) 11.8 isn't so bad? What say you Jeff!
Hi Richard, that's correct, a lead acid battery will drop voltage over time. Choosing to go lower then 12 volts is a choice, and if you have AGM batteries you can do so once in a while, knowing that the lower the battery voltage goes you also in turn reduce the number of battery cycles.
Hi Jeff, with all these 200ah and 300ah batteries on the market, does it make any sense to buy a 100ah marine grade battery anymore these days ?
I look forward to hearing back from you.
Good question. When sizing a battery bank, we generally try to keep the number of batteries' to a minimum. If redundancy is important to the boater, we'll sometimes, build a battery bank with at least two batteries in parallel, so if one battery fails it can be isolated.
I been off grid 3yrs I was about to get 2 trogen t105 for $159 each with cores He sent me a message saying he had 2 agm batteries reconditioned $75 each straight out no core I like to know what you think?
Hmmm, hard to quantify what does "reconditioned" mean? Is the battery 50% or 75% of capacity. It's a tough call to buy used batteries as you don't know how the batteries got abused.
I have 2 agm batteries from autozone in my camper that are 7 years old and still show no signs of weakening
Thanks for sharing, AGM batteries should give you longer life then flooded lead acid batteries.
AGM does not do well with a partial recharges correct? Say you start off 100%, underway drop to 80% after short cruise with loads, then shut down overnight at anchor, next time you start you only run for enough of maybe, let’s say 5% recharge, and keep repeating so as to only ever get around 70%-80% while out of your boat slip/shore power top-off, …Up and down from less than full charge shortens the battery’s life, even if you never drop below 30-50% DOD?
To keep a long battery life with AGM, they should be periodically recharged to 100%. From experience, many AGM batteries seem to have shorter lives when left in a partial state of discharge for long periods of time.
.difference of lithium and grl batteries tube
Hi Neil, can you please rephrase your question?
Hi .. Ok Can you do a comparison between AGM and Carbon ?? relative capacity/volume etc
There is already two videos about it on the PYS channel. Search for Firefly.
@@PacificYachtSystems Thanks ;-)
If you already have AGMs, use them up before replacing, but don't play games, these days LiFePo4 is the ONLY chemistry to consider. Even if the outlay is twice that of any other common chemistry, which it is, the cost in and out over time is dirt cheap, compared. Underspec the battery if you are forced to, but do LiFePo4. :)
I don’t actually agree. I’ve just been through this decision process. Before we started I was absolutely convinced I was going to swap my old flooded lead acid to lithium. But as we started to look at the impact of switching to LifePo4 on all our systems (winches, bow thruster, windlass, and alternator) the additional costs were rapidly approaching the of the cost of the lithium batteries themselves, doubling the total cost. So suddenly the ROI calculation changes. In the end I swapped our 3 x 140 flooded lead acid to 4 x 170 of the latest super cycle Victron AGMs. Using Jeff’s suggestion of 70% DOD that means I could go to 476 ah, more than I was going to get under Lithium and at a minimum of a quarter of the price. At the cost I could replace them 3 or 4 times over (15-20 years?) and still be about the same total cost of switching to LifePo4. To be clear, I’m not dismissing lifepo4 in the longer term, but our boat isn’t ready for the switch yet. Maybe in 5-7 years time I will have made a number of upgrades, the cost of the lifepo4 batteries will have dropped further and the technologies will have matured more, then I can look again. Or maybe there will be something even better. Until then I’m really happy that I made the right choice for our boat.
Hi Martin, I’m curious to know how lithium batteries would affect your windless and bowthruster?
Pete
@@petergibson6563 Are you a pro? I’m not so I can only say that the views I got on this topic varied. Depending on the battery manufacturer, there is a risk that the Lifepo4 BMS will shutdown during very high current loads like bow thrusters, windlass or winches if the current exceeds the manufacturer’s threshold. That’s a risk I don’t want. Then there was the complexity of dual charging different chemistries via the alternator. Again opinions differed and again I didn’t want to take the risk of trying different solutions.
Even though Lithium batteries offer lots of benefits in comparison to lead acid battery, Lithium is not necessarily the right choice for everyone.
@@freakent Thanks Martin, interesting point! No I’m not a professional.
Really respect your knowledge but it seems like you are against lithium what would be the argument against something like battleborn batteries for
Hi Tom, my advice to fellow boaters is there is no perfect battery for everyone. Lithium is a strong contender for boaters that need the most energy density out of a battery bank. If space and weight is really important to you, then Lithium makes lots of sense. Also if you plan on using your battery bank extensively, like a liveaboard and you'll be cycling the battery thousands of times over years to come, Lithium is a strong contender. All that said, Lithium does come with a price tag many boaters cannot afford. And NOT everyone needs the benefits of a Lithium battery.
JEFFFFFF!!!!! I'M SCREAMING at the video. You forgot to say: "AGM batteries ARE LEAD ACID TOO, but not WET CELL lead acid.
Thanks for the reminder... i need to be bettter.
If your AGM isn't getting the higher voltage needed to reach full rated capacity, your AGM battery will provide LESS capacity than rated. Sheesh.
Why are people still buying lead batteries in 2020? LFP is where it's at.
Thanks for sharing.
AGM batter for lawn mower $149, best lead acid battery $49 so you tell me why AGM?