Problems with renogy bluetooth bms

[0_cool]

Hi everyone.

I'm somewhat new to all this and hoping someone here might know what's going on.

I believe I may have overdischarged a renogy 200Ah lithium battery by hooking it up incorrectly and having a short.

When I got it all disconnected, I checked it and it wasn't showing any warnings on the bluetooth app, and the 400amp fuse went.

What I'm experiencing is that the BMS seems to be giving incorrect battery SOC percentages. It appears that it won't go below 87%.

I've had it hooked up to a small load to draw it down to 40-60% for storage and checked it today. It showed 87% charge but the app was giving an over-discharge warning... It was at 10.8 volts.

Any idea if I've fooked the battery, or if there's anything I can check or do here?

I also have a shunt and could just use that instead of the bluetooth app, but I'm concerned that if one thing is malfunctioning in the BMS then how can I know there aren't other malfunctions?

Thanks in advance everyone!

 

[mikefitz]

87% SOC app was giving an over-discharge warning... It was at 10.8 volts.

Renogy batteries seem to cause problems for many users, a search on this forum will bring up many issues.

It's possible the battery is in protection mode. 10.8 volts and 78 % SOC cannot both be true.

A protection short should self recover unless the BMS is damaged during the short circuit and the loss of a 400 amp fuse indicates that this is possible.
Do you have any further info on the battery state, like cell volts via the BMS, and battery terminal volts with a voltmeter?
Does the battery deliver and accept current?

You could try asking Renogy for a replacement if the battery fails to accept or deliver power.

Worst case if you want to DIY a repair is a failed BMS. Again a search will find info on this approach.

Mike

 

[0_cool]

Thanks Mike.

I asked renogy and they told me to charge to 100%, discharge to 20%, charge to 100%, then Voila she'll be fixed.

Is both accepts and delivers current.

The actual battery voltage level is accurate, just the % remaining charge was way off.

Currently it's trading 81% remaining at 13.2v. I'm not sure exactly what that means. My external technology battery monitor says it's at about 45% remaining though... I'm going to go by that, take a bunch of screenshots and pictures along the way, and hopefully it'll fix itself. If not then hopefully renogy will honor the warranty.