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Litime 12v 200A Plus

That sounds to me like a dead cell or maybe 2 of them... 3.2 * 8 = 9.6 ... or just 3.0 * 3 = 9... you get the idea...

Or they could all be in the 2v range someplace...

If they let you keep them after the warranty claim you can pop the tops and try charging individual cells with a benchtop supply... something like a 0-30v, 0-10a that does constant voltage or constant current.
 
Same, no change at all. Stuck bouncing around 9.xx- 8.xx with charger on. Take charger off and drops like a rock. 😡

Slows down at 5.19, .18, .17...
Sorry to hear that. Were you able to measure any charge current??? If minimal charge current is flowing it could take quite a while to bring the battery voltage up if the cells are really depleted.

My guess there is no charge current flowing. Open mosfets (which stop charge current from flowing) sometimes result in erratic, low voltage readings.

*If* you measure *no* charge current (and since none of the chargers appeared to "wake-up" the BMS), I would suggest momentarily paralleling (pos to pos, neg to neg) a fully charged 12v battery with the problem battery as a last resort to attempt to wake-up the BMS before giving up on your current approach.

If this fails and LiTime provides no-joy with a warranty claim, you may want to consider cutting into the battery case to charge the cells/battery directly like @robbo2112 suggested. It's relatively easy to do. Cutting through the plastic case is probably the hardest part.
 
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LiTime batteries have pretty clear documentation on how to "store" a battery for an extended time (6 months or longer); if it wasn't done correctly, I can see the battery going into sleep mode to protect itself, and/or getting damaged.

Even though all these batteries are LiFePO4, each vendor uses their own version of a BMS, and the engineers have to come up with their own battery docs that detail what you can and can't do with them. If we don't read the manuals when we buy a battery, we'll do something the vendor didn't intend, and possibly void the warranty. Some dangers: not storing them correctly for long-term storage, hooking too many in serial or parallel mode, etc.

If they are just in sleep mode, you'll want a true LiFePO4 battery charger with a "wake-up" function ... the docs for the battery charger should tell you how to invoke that function and wake up a LiFePO4 battery when the BMS has put it to sleep. I've been successful in using a NOCO LiFePO4 battery charger (with a wake-up function) to wake up my LiTime batteries (when I drained one too low, and the BMS jumped in front to protect it).

Hope this helps ...
 
Im not sure what the BMS expects to see for it to 'wake up' but the only remaining optimistic possibility other than 'that things broke' is that it needs to see more than 9v to wake up, or for a longer time. Keep in mind all SMPS chargers have a pulsed output and a multimeter is not an oscilloscope. Ive seen numerous SMPS devices have an annoying 'failure to launch' loop where they briefly pulse their outputs, decide they dont like the circuit, and then go into an endless loop of failure to launch where they just briefly pulse the output over and over but never 'stay on'. Likewise, if the BMS expects to see a certain voltage for a certain time it could just be that it's not staying above that voltage long enough because of the pulse duration, and the meter may not be showing you an accurate 'peak' voltage value if it doesn't stay at that voltage for long enough. If you have a way to put a CONTINUOUS 12-14v to the battery id try it. The 8-9v doesn't bother me much (yet) because it could just be a very brief >12v pulse against the capacitance of whatever is still hooked up to those terminals, not raising that circuit all the way to >12v. Then the charger retries and you end up 'averaging' 8-9v even if it very briefly goes to 12+. That's why i think the "continuous" ie non-pulsed >12v is still viable. If that doesn't work either then you're either gonna have to pry that thing open or get it warrantied.
 
When I suggested the old style battery charger I meant the constant current with a switch for 3 or 10 amps.... it just puts out 13.4v when it is plugged in.

I think the OP tried that sort of charger... it is warranty time
 
Do you have any other 12v lead acid batteries around? They are the best constant voltage source to straighten out the BMS

A little lawnmower one?

I’d use that and try and jump start the BMS.
 
That sounds to me like a dead cell or maybe 2 of them... 3.2 * 8 = 9.6 ... or just 3.0 * 3 = 9... you get the idea...

Or they could all be in the 2v range someplace...

If they let you keep them after the warranty claim you can pop the tops and try charging individual cells with a benchtop supply... something like a 0-30v, 0-10a that does constant voltage or constant current.
Warranty claim has been started, but it appears I have to send them back.
 
Do you have any other 12v lead acid batteries around? They are the best constant voltage source to straighten out the BMS

A little lawnmower one?

I’d use that and try and jump start the BMS.

That was the 1st thing I did before jumping onto this forum, no dice.
 
When I suggested the old style battery charger I meant the constant current with a switch for 3 or 10 amps.... it just puts out 13.4v when it is plugged in.

I think the OP tried that sort of charger... it is warranty time
Yep. It's been submitted.
 
They will sometimes say they want them back to get you to keep them, then when you insist on warranty they will ship the new ones and never send out a return label.
 
Appears they are prorating the warranty. Is this normal?

Our battery comes with a five-year warranty, and your order#LT8411 is already over a year old approximately 15 months. The order total was $1,254.31, and the refund total would be $730.81.
 
Looks like they spell it out on their website - you could use the wayback machine to determine if it has always been that way.... if it was you are stuck with it... it was different when you purchased the batteries you can probably negotiate some...

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