I recently added an additional two pylontech batteries to my existing stack of four.

I noticed over the last few days that the charge jumps from 88% to 100% within a minute. The discharge seems fine though

 

This has been going on since i installed the new Batteries.

I added the batteries as specified ex:

1) Existing batteries should be around 80% charge
2) New batteries should be added to the top of the stack
3) Allow re-balance

The existing batteries was around 86% when i added the new stack, i believe the new batteries come charged at 80%. I am just worried that there might be something wrong with the new batteries, or there might be a system setup problem. I am Using Victron inverters, I've updated the settings to accommodate the new battery bank size.
 

oh... the batteries used are all Pylontech US2000's 

Mine also does that little jump from 88% but it doesn't look like its just in 1 minute tho - closer to 20-30mins here

Also Victron - both a 3kva multiplus II + a 5kva looks like the same pattern

my batts are the pylontech 3.5kwh x 3

2 minutes ago, Pietpower said:

pylontech-soc-jump-while-charging

thx

If you overlay the Pylontech's battery voltage with the SoC you will notice this happening:

 

I also saw this sort of thing happening at the low end of the charge scale too.

Batteries got down to 21% and stayed there. I didn't wait more than 5 minutes to let it get to 20% so ICC could switch to grid and start charging. Would hate for this to happen to someone, and their batteries accidentally drain down to 0% because the BMS was still showing 21%.

I have since set my min battery switchover SOC to 25%.

It's not a pylontech thing. I have this with Revovs as well. The explanation that @Pietpower linked to resolved my confusion on this matter.

Edited February 17, 20205 yr by Bobster