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jwcolby54
Hudson nc
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Joined: 09/15/2023
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I found a very good youtube video on lithium vs lead acid. It is by an engineer who did extensive side by side testing in the lab where he could get consistent results for each battery type he tested. It is somewhat long but very thorough.
https://youtu.be/iy3hga_P5YY?si=tr2yG_na_vB5rHmQ
It was done at BattleBorn but the results are the same for other manufacturers.
JWColby54
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pianotuna
Regina, SK, Canada
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jwcolby54 wrote:I found a very good youtube video on lithium vs lead acid. It is by an engineer who did extensive side by side testing in the lab where he could get consistent results for each battery type he tested. It is somewhat long but very thorough.
https://youtu.be/iy3hga_P5YY?si=tr2yG_na_vB5rHmQ
It was done at BattleBorn but the results are the same for other manufacturers.
Thanks for finding and posting this.
Unfortunately they did not cycle the lead acid batteries BEFORE testing.
Lead acid / agm are rated at 25 amps discharge, so testing at 40 amps is not a level playing field.
The low voltage cut out is interesting. I wonder if going to 10.5 UNDER load is the same as discharging capacity to 10.5 volts?
Last winter because of snow cover my house bank went to 8 volts. It has recovered nicely.
I do use my rv at -34 f so Li unfortunately won't be in my future.
* This post was
edited 09/17/23 10:43am by pianotuna *
Regards, Don
My ride is a 28 foot Class C, 256 watts solar, 556 amp-hours of Telcom jars, 3000 watt Magnum hybrid inverter, Sola Basic Autoformer, Microair Easy Start.
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DaCarmack
Lake Isabella
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I ran into the same problem as you are. I have a coachman Concord 275DS. There's only enough room for one battery without extensive modifications that do not want to do. If You have the measurements of your battery box You can look at AGM's in the solar field. I put a battery called a mighty Max It was 135 amp hours that worked really well. Then I came into possession of a battery called NPP that is 155 amp hours. This was the biggest battery high-wise I could fit in my box that's in my step. The only modification I had to do was to extend the threaded rods for the safety strap. Now if I'm at a rest stop I don't have to worry about power. we can turn on this light or that light, we can be wasteful is the best way to put it. You do need to make sure that your converter can charge it at the right voltage which I believe is 14.6v, the one I have is just at the minimum and I haven't had any problems
2005 Coachmen Concord 275ds
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jwcolby54
Hudson nc
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pianotuna wrote:jwcolby54 wrote:I found a very good youtube video on lithium vs lead acid. It is by an engineer who did extensive side by side testing in the lab where he could get consistent results for each battery type he tested. It is somewhat long but very thorough.
https://youtu.be/iy3hga_P5YY?si=tr2yG_na_vB5rHmQ
It was done at BattleBorn but the results are the same for other manufacturers.
Thanks for finding and posting this.
Unfortunately they did not cycle the lead acid batteries BEFORE testing.
Lead acid / agm are rated at 25 amps discharge, so testing at 40 amps is not a level playing field.
The low voltage cut out is interesting. I wonder if going to 10.5 UNDER load is the same as discharging capacity to 10.5 volts?
Last winter because of snow cover my house bank went to 8 volts. It has recovered nicely.
I do use my rv at -34 f so Li unfortunately won't be in my future.
Let me start by saying that I am not an EE, however my job for 15 years was fixing electronics, back in the day when a thorough understanding of all things electronics, schematics, o'scopes and soldering irons were the tools of my trade. So I understand this stuff fairly well.
The fact is that lead acid works quite well if you pretty much stay plugged in, or only use the battery for led lights and the water pump etc. Trying to put a high current long draw device on it is where lead acid fails rather spectacularly.
As for 25 amps vs 40 amps level playing field... there is no level playing field. One doesn't get a choice about current draw. Once doesn't get to "cycle before" etc. One turns on a device and one gets what one gets. The Puekert effect is real. Put a 2kw inverter on a lead acid and enjoy the show. Put it on a LiFePO4 and enjoy your hot coffee from your microwave. It really is as simple as that. Even several lead acid batteries in parallel will droop radically under heavy load. I know, I have watched it. Many electric devices do not enjoy trying to run at 11.9 volts which is a very real result of a very high current draw on lead acid.
Every tool has it's uses. Lead acid's use case is low current over long times. Or (for starter batteries) extremely high current over extremely short times. It is decidedly not extremely high current for more than a few seconds. Whatever you do, do not attempt to run an inverter higher than perhaps 500 watts on lead acid, and try to pull full power for long times.
One final thing, LiFePO4 simply doesn't care if you fully discharge it. Lead Acid will die rather quickly if you do that repeatedly.
Every tool has its place.
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pianotuna
Regina, SK, Canada
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jwcolby54,
Lead acid brand new need to have several discharge recharge cycles to reach their full capacity. This was not done prior to the testing.
https://batteryuniversity.com/article/bu-804-how-to-prolong-lead-acid-batteries
"Formatting is most important for deep-cycle batteries. They require 20–50 full cycles"
Further lead acid do best when discharge is limited to about 1/4 C.
I love li batteries but can't use them due to cold weather. I boondock at -34 F. My first battery bank was 875 amp-hours.
* This post was
edited 10/01/23 10:23am by pianotuna *
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jwcolby54
Hudson nc
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pianotuna wrote:jwcolby54,
Lead acid brand new need to have several discharge recharge cycles to reach their full capacity. This was not done prior to the testing.
https://batteryuniversity.com/article/bu-804-how-to-prolong-lead-acid-batteries
Further lead acid do best when discharge is limited to about 1/4 C.
I love li batteries but can't use them due to cold weather. I boondock at -34 F. My first battery bank was 875 amp-hours.
LOL, which has nothing to do with the big picture results. If you like lead acid, use lead acid. Just don't try to do high current long time period draws, regardless of how many cycles you have already used the battery.
More stuff on lead acid
And as for the temp thing, move the battery inside your camper. Or insulate the battery box well. Or heat it. Or both. Unless of course you are letting the inside of your camper reach -34 F in which case I can't help you.
Again, there are those willing to fall on the sword for their lead acid batteries. I am not. What you do with your rig is none of my business, but to claim lead acid is the best thing since sliced bread ... it is not. Sliced bread makes much better PB&J Sandwiches.![[emoticon]](http://www.rv.net/sharedcontent/cfb/images/wink.gif "wink")
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pianotuna
Regina, SK, Canada
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Hi,
I think LI are wonderful. They are, unfortunately, not a good fit for me.
When the RV is in storage it gets down to -40, so no you can't help.
* This post was
edited 10/01/23 07:36pm by pianotuna *
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