Low voltage when at 40% SOC. Why?

[Kemp Outside]

I just set up my first system with 2 100ah Weize batteries, a Victron SmartShunt and Renogy 2000 watt inverter. Batteries are charged by a Victron IP22 AC charger (shore power) for now until I’m able to add solar. I was texting the system to see how long it would run my 120 volt AC refrigerator in my camper as well as a 42 quart 12 volt freezer from Alpicool. I think I have everything set up correctly with the shunt, claiming a 200ah battery and setting everything for Lithium. Starting from 100% SOC, everything ran fine until sometime over night, my voltage dropped to about 10.4 even though I had 40% SOC left. Any idea why that would happen? What am I missing?

 

[MiSh]

Take all the loads off your inverter then check for voltage. If there is a load it will normally pull the voltage down. That, and most likely your batteries weren't really @100% to start.

 

[Supervstech]

Either the shunt isn’t correctly setup, or it isn’t calibrated to the setup.

Post pictures of the wiring.

 

[Kemp Outside]

Take all the loads off your inverter then check for voltage. If there is a load it will normally pull the voltage down. That, and most likely your batteries weren't really @100% to start.

I turned the inverter off and smart shunt was still reading 10.4 volts. I fully charged both batteries independently before hooking them together in parallel.

 

[Kemp Outside]

Either the shunt isn’t correctly setup, or it isn’t calibrated to the setup.

Post pictures of the wiring.

 

[Kemp Outside]

This is my temporary setup while I test components. Everything will be removed and reinstalled in my trailer once I am ready.

 

[corn18]

In my experience, it takes a few cycles to get the SOC calibrated.

 

[soylentgreen]

nevermind

 

[corn18]

nevermind

Great album.

 

[Brucey]

I turned the inverter off and smart shunt was still reading 10.4 volts. I fully charged both batteries independently before hooking them together in parallel.

Turn the inverter off, and charge the batteries till they sit in float. Check in Victron connect that they took around 200Ah. Then click on Synchronize. Also make sure Battery SOC on reset is set to Keep SOC.

 

[Brucey]

What does your History tab show?