Resetting BMS on my LiFePo4 battery

[INTJohn]

Soooo I connected my 120 watt solar panel to my 100 ah LiTime LiFePo4 batt and managed to trip the BMS (battery management system) due to an overcharge error code. What exactly caused this I haven’t fully investigated yet but I have a couple hunches.

The good news: the BMS worked as advertised and shut the system down and I immediately disconnected the panel. Yay! But nowhere in the instructions for idiots pamphlet does it explain what to do to reset the thing.

Google is my friend:


Yep, I discharged the battery to about 25% capacity and then followed advice on first recommendation to try and that first thing accomplished the reset. Yay!!

Disconnected everything from the battery; let it sit for about an hour (advice says 30 minutes)
Then connected my 400 watt solar panel and battery was recharged to about 95% capacity and now my LiFePo4 battery and I have a great love life once again……..

intjonny gettin charged up

 

[RvNaut]

So.. you are not using a charge controller? ...and you are connecting the panels directly to the battery?

 

[tx2sturgis]

That's how I read the first sentence.

But...a solar charge controller MUST be used in the charging circuit.

(there are a few limited exceptions but this is not one of them)

 

[INTJohn]

Used a charge controller. That’s why I’m still abit confused as to why the overcharge error. Still gotta figure that one out but my issue was how to reset the BMS so the batt can be recharged after use.
Having discovered how to do that via google & you tube; posted how to do that; at least for my particular batt.

INTJohn

 

[rruff]

Since I just got a Power Queen, which is likely made by the same outfit, these are my experiences while playing with it...

It quits charging at ~13.7v (BMS shutdown), which is pretty low. I'd guess your charge controller is set higher. Up to 14.6 is actually ok, but there is hardly any energy in that extra .9v. The website says it's ok to charge up to 14.6 also, so why the hell is the BMS set lower? Set your charge controller to 13.6 max and see what happens...

I've tripped the BMS a few times. Very minimal draining is necessary to reset it. 3Whr is enough, and possibly much less... like any.

I'm doing a capacity test at this moment. Not a real good one since I don't have a battery monitor, but I have little inverter and a Killawatt. I figure the inverter is 80-85% efficient. Got it hooked up to a heat lamp positioned under the desk, to blow sunshine up my skirt!... sorta. So far 1030 Whrs have been consumed at the meter, which would be 1248 at the battery... if I assume 82.5% for the inverter. The battery is rated for 1280Whr so I think it will do fine...

 

[rruff]

It went to 1140Whr (which is surely even with 85% efficiency on this crap inverter, 1340Whr) before the BMS kicked in, and a few seconds later the voltage was 11.7v. A few minutes later it's up to 12.04v. If you set the low voltage in the 12v+ range, that would be fine.