ESS 0% but Inverter don't stop discharge

DIY
, ,
1

Hi all, hope to post on correct section.

I have a system with mppt 150/100, a multiplus 5KVa, all under a CCGX, and recently I’ve upgraded my battery pack from a LG chem resu 6.5 to a DIY pack of about 15kwh with a JK BMS

With the old battery, I’ve used for over 6 years, usually I’ve setup ESS to use it from 10 to 100%, leaving a 10% of SOC just for the rarely disconnections or outages from grid

With the new battery I was looking to maximise ESS due I’ve already leaved a margin of change left in the BMS settings ( 0% cell voltage reset a bit higher than under voltage protection)

I noticed if I set any value in ESS settings higher than 5%, inverter work correctly and stop to discharge battery ( for example, I set SOC limit in ESS to 20% and the inverter stop to discharge my pack when reach 20% soc)
But if I set ESS SOC to 0%, multiplus continue to discharge battery over 0%, untill the UVP of the JK BMS disable the discharge

I’m missing something or this is the correct way ESS should work with 0% soc setting?

(Hope to had explained well and sorry for my bad English)

2

ESS doesn’t support a 0% setting as the built in hysteresis won’t work.
It does not cater for that use case.

1 Like
3

Thank you for fast reply

So, if I’m looking to reset 0% soc on my battery ( example, to check SOC drifting errors in winter season ) I need to set manually ESS to 0% and set it back to 5 % or higher, right?

4

Drift is best addressed by letting the battery fully charge so it synchronises and balances.

1 Like
5

Yes, you right, but my PV panels sizing in winter usually don’t permit my system to fully charge

If needed, I will do a 0 o 100% reset manually from settings, thank you for Infos about! Regards