2 batteries in parallel with different SOC

[Capt Tango]

2 FOIIOE VESTWOODS 12V 300Ah with 200A BMS Plus and Ultra (Don't know the difference) 1,600 Watt solar array using a magnum 3,00 watts Charger/Inverter set to factory Lifpo default setting.

Just up and running yesterday and charged to 100% each before combining them, then used the inverter/charge and topped them off.

Just finished installing my RV am off the charger I ran the heater all last night, boiled coffee this morning and now have lights and computers running. batteries were at 32% SOC and 62% respectively. Is it normal for one battery to have a lower SOC or do I need to cycle the system for several days to equalize them.

Battery Current readings: Total of 600 Amp Hours connected in parallel.
Battery 1 13.3 Volts 11.30 Amps 33% SOC
Battery 2 13.4 Volts 12.30 Amps 63% SOC
Voltage stays the same Amp vary from 11 to 13 SOC is increasing on both.

Solar Charger Readings: Total of 1600 Watts (Overcast day)
PV
655 Watts
36.63 Volts
18.1Amps (increase as noon approaches)

Batteries
13.95 Volts (Increasing)
44.7 Amps
Bulk Charging

Both batteries are charging at about the same SOC rate increase but have drastically different SOCs.

 

[sunshine_eggo]

How are your main leads connected? Are they both to the same battery, or are they "across" the bank, i.e., main (+) on one battery and main (-) on the other.

If the former, it will draw more from the battery attached to both leads.

In any case, check torque of all connections.

See link #6 in my signature.

 

[windsurfer]

It usually takes the SOC monitors a few cycles to calibrate themselves. If that doesn't take care of itself, there must be a problem with wiring/connections.

 

[Capt Tango]

How are your main leads connected? Are they both to the same battery, or are they "across" the bank, i.e., main (+) on one battery and main (-) on the other.

If the former, it will draw more from the battery attached to both leads.

In any case, check torque of all connections.

See link #6 in my signature.

 

[time2roll]

Looks good to me. Give it a week and report back. SOC should consolidate as voltage approaches 14.00

 

[Brett V]

Once the battery at the higher SOC reaches saturation, its current will drop sharply and the other one will catch up. As Eggo said, check your connections and make sure they're good.