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New setup: How do I know SOC of batteries?

gcp

Going nomadic.
Joined
Sep 1, 2021
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Hey there. I just hooked up a new system with two 170ah lifepo4 batteries (12v) with the Victron SmartShunt. The SmartShunt wants me to tell it the state of charge of the two batteries. How do I determine the SOC?

Is it really just a matter of looking at the battery voltage the smartshunt reports and cross referencing that with charts like this one:
https://diysolarforum.com/resources/general-lifepo4-lfp-voltage-to-soc-charts-tables-12-24-48v.109/

My bank’s voltage is 13.27, so looking at the charge I guess my bank is at 77% SOC?
Power System Wiring Diagram v4.5.001.jpeg
 

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You can make a guess and set it if it is important to know a basic state of charge right now, but the Victron will syncronize every time the battery is charged up to 100%, unless you tell it to do otherwise when you set it up.
 
Maybe you could charge them fully, and then tell the shut that they are 100% charged?
Will my batteries know when to stop charging themselves? Do the solar charge controllers and inverter charger need to know the present state of charge? Forgive my naïveté ?
 
You can make a guess and set it if it is important to know a basic state of charge right now, but the Victron will syncronize every time the battery is charged up to 100%, unless you tell it to do otherwise when you set it up.
The victron will know when it's fully charged without me having to do anything?
 
The victron will know when it's fully charged without me having to do anything?
Yes, IF you set it up correctly. You have to tell the shunt the battery chemistry, voltage, battery capacity and etc. Just follow the steps in the manual.
 
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