question

Greg avatar image

State of charge

Hi

I have a 12volt 100 amp hour new lithium battery .

Charging battery is a mppt 75 l 15 smart solar charge controller and a blue smart charger 12l 25 with Bluetooth both connected to smart shunt.

State of charge on shunt stays at 100% even whilst charger and mppt are putting 34 amps into battery.

What do I need to change to get an accurate SOC reading.

SOC
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2 Answers
kevgermany avatar image
kevgermany answered ·

To add.

Set 100% synch value voltage to just below absorption voltage. Tail current might need to be lowered. Tail current time raised. This is because of cloud interference with solar when off grid.

Setting initial value to 100% seems to be default because otherwise it starts at 0% and immediately triggers a low battery alarm when you connect the shunt and monitor.

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Matthias Lange - DE avatar image
Matthias Lange - DE answered ·

After the first connection the SmartShunt always shows 100% because it doesn't know the real SOC.

You need to fully charge the battery to synchronize the SmartShunt to 100% SOC.

I'm pretty sure that is described in the manual of the SmartShunt.

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