I really need some help with the correct Inverter and ESS Settings for my new config.
I have the following:
- 3x MP-II 5000 in a 3 phase config
- 3 strings with 16 REPT 280AH LIFEPO3 each with a JK BMS, total 840AH. REPT specs seem extremely similar to CATL and EVE.
- max discharge load 70 amps per inverter
The system has just been brought up since 24 hours. Initially, doing some testing with lower loads were all fine. As soon as I increase discharge load then then the voltage of the string drops quite a bit after the battery gets below 50% SOC causing battery low warnings. Voltage ultimately ends up being 45V where the BMSs (not connected to the ESS) and the smart shunt still think the SOC is 42%. So that is one challenge I have. I made some changes to the settings but I don't think I want to go too low (e.g. 42V cut off) under load. If anyone has any hints as to how to arrive at the best settings and why there seems to be a discrepancy between the SOC and voltage then please shout.
Secondly, I just tried the charge cycle which seems to work similarly: the moment the load increases, voltage goes up quite fast causing the MP-IIs to reduce power quite quickly. From 45V to 52V took 30 minutes where the SOC went from 42 to just over 47. Any advice on charge settings here would also be appreciated.
In summary, the batteries seem to vary quite substantially in voltage under high loads causing the system to struggle with load/unload parameters.
Thoughts? Many thanks in advance.