Hi all,This video is pretty clear. It seems it would be best to have a battery management system that would not go below 20% (1/5th) state of charge.https://www.youtube.com/watch?v=HCIlaXaVeF0

I’m not sure why he chooses to use the word ‘Lies’?? After watching his presentation, seems to me like an overstated use of a ‘trigger word’ to illicit audience clicks, while in the end he’s merely providing some fair minded information that might seem self-evident in actual practice…Another case of unnecessary hyperbole (trolling confirmation bias??) subsequently cloaked within some facts…’Viewer Discernment Required’…Either way, in the ‘real world’ of drop-ins, the actual battery capacity can often be slightly greater than even the mfg’s advertised spec’s - Case in point: my LFP bench test at 7% over mfg’s spec capacity, so even at an indicated zero SOC, 7% capacity remains in reserve (meaning longevity unaffected), suggesting the advantage of bench testing…FWIW, I’ve even brewed the Keurig at 125amps at zero % SOC…A 20% SOC BMS Cut-out, really?? (why so??)3 tons

I have read from a number of other sources that like wet batteries, the depth of discharge greatly influences Lithium battery life.

My take on the video is what I KNOW and have experianced for both Li and AGM batteries for the past 10 years. LI are GREAT as are AGM's. BUT you can fully discharge a Lead acid DEEP CYCLE battery and as long as to do a slow steady recharge the battery will resume almost 100% efficiency. It has lost some of its life cycle, but minimal. Li and AGM, you completely drain them dead and leave them dead for more than a few days, well you now have a very heavy small boat anchor. They will NEVER recover their life cycle or even stay charged. This has been a big headache trying to get the idiots in our sales dept to keep our B vans that now come with LI(used to be AGM) plugged in and charged. They rant and rave when they have to buy NEW batteries for when they sell that Motorhome and we try to educate the Sales manager, but they keep buying new batteries because WHY? Because the Makers of the Li and older AGM KNOW the only way a NEW battery could be bad because they were allowed to discharge completely. Doug

Easy to have the BMS cut at 20% capacity if you build your own.Can sit at 20% for 6 to 12 months without issue.Dealer proof ;)

Agreed, sounds like your Sales folks need to be acquainted with the concept called ‘Lot Rot’ and parasitical drain - waaay cheaper than replacing perfectly good batteries…Most Sales folks I’ve encountered have never even owned RV’s…3 tons

can LiFePo4 be totally discharged (from a dealer)

pianotuna
Nomad III
Jul 17, 2022
Li are unforgiving. It behooves the end user to follow directions from the particular maker "to the letter", if they want long life.

Unfortunately they do not meet my needs--and the one Li chemistry that would work is a best fit with a 48 volt house battery. I'll struggle along with what I have, for now.
3_tons
Explorer III
Jul 17, 2022
PT says, “Li’s are unforgiving. It behooves the end user to follow directions from the particular maker "to the letter", if they want long life.

Since your opinion is unqualified (as a non-experienced LPF user, and ardent SiO2 campaigner), while this is the second link you’ve ‘cherry picked’, in an attempt to muddle authentic LFP discourse (very sad…), for the larger audience perhaps you might reconsider these attempted misleading errant crusades??

3 tons
RickLight
Explorer III
Jul 17, 2022
Modern retail LFP have BMS built in.

If I lose 10% life I'm still 30-40% ahead.

This discussion is a tempest in a tea pot!
time2roll
Nomad
Jul 17, 2022
pianotuna wrote:
Li are unforgiving. It behooves the end user to follow directions from the particular maker "to the letter", if they want long life..
Actually the BMS should protect if set up properly. Very little the user can do that is unforgiveable.
The link at the top is a poor reference to anything to do with LFP batteries.
pianotuna
Nomad III
Jul 18, 2022
"if it is set up properly" That's the rub. How do folks know what they don't know?
time2roll
Nomad
Jul 18, 2022
pianotuna wrote:
"if it is set up properly" That's the rub. How do folks know what they don't know?
Verify the warranty and send it in for exchange.
Typical deep cycle FLA is one year warranty, LFP is often five year warranty. That is 5x the life right there.
StirCrazy
Moderator
Jul 18, 2022
pianotuna wrote:
Li are unforgiving. It behooves the end user to follow directions from the particular maker "to the letter", if they want long life.

which is the same for any battery type. even your self proclamed best chemistry type that you don't own. they are probably even more fussy than LFP, but they will give you some power at -40 so they work for you.

aside from setting up my solar charger with custom charge levels and cutoffs (took me 3 min, ok 5, had to reconfigure my bluetooth controler on my renogy) I have treated it like a plug and forget battery and it has preformed wonderful. I think the only thing I dont do is plug it in when I get home, just let the solar take care of that and the only different thing Ill do is I may take the battery out when I winterize and put it in the heated garage, don't need to in my climate but heck why not its only 44ish lbs for 300ah instead of the 180lbs of wet cells.
3_tons
Explorer III
Jul 18, 2022
It’s not clear to me what might set someone off where one opts to engage in such forum mischief, but oddly such ‘self-serving endeavors’ do exist…

3 tons

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