Weize Charging Problem

[SprintJeep]

I recently bought 4 12v 100ah Weize LifePO4 batteries. I was noticing that I was only getting 300ah out of the bank wired in parallel. I took the bank apart, and 1 battery was at 10.9 v while the others were fully charged. They are charged via a Multiplus 3000. I charged the battery back up individually, then did a load test at 20 amps back down to the voltage cutoff, which it passed. Now it won’t charge with my Multiplus or my other lithium charger. The multiplus attempts to charge it but it won’t accept it. Weize keeps telling me that I need a “0 volt” charger or to wake the battery up with one of the other batteries in parallel. I’ve tried that and it doesn’t work. Any ideas to wake the BMS up in the battery? It’s currently at 9.15v.

 

[sollap]

Maybe the cutoff battery is enough of an initial load to trip the BMS of the good battery? A voltmeter across the terminals of the good battery would tell you if it's dropping out upon connection to the weak battery. If that's what's happening, putting your good batteries in parallel before connecting the weak battery should overcome that.

 

[SprintJeep]

They recommended connecting 2 batteries in parallel with 18-22 AWG wire to wake the battery up. It didn’t do anything. I feel like Weize is giving me the runaround.

 

[sollap]

Are you someplace where it's cold enough that the low-temp protection may have kicked in?

Did you leave the good batteries connected to the bad one for 5 minutes or so? It might not be an instant thing - I don't know the details of the BMS in those batteries. I don't see any harm in leaving them connected for a while though.

 

[SprintJeep]

Just a minute or so. They advised 10-30 seconds. It’s been warm here so no cold weather issues.

 

[Solo Sailor]

I too have a Weize 12.8 v 100 ah battery. Maybe you have this info : when you programed your charge controller did you specify LifePO4 4S or 5S? I don't intend to hijack your thread but since I am not sure I wondered if this would have an effect on your charging resulting in damage.