Lithium Ion Battery Cell voltage vs SOC vs Amp hours

Thread Starter

MikeJacobs

Joined Dec 7, 2019
226
I am trying to figure out how to explicitly correlate battery Amp hours with State of charge and voltage

So as we generally accept, an Lithium Ion cell

Has a min low voltage of 3.2V and a max of about 4.2 volts

ok great no issues here. We also would say that at 4.2 volts its at 100% SOC and at 3.2V its at 0% SOC???? Is that true?

Also, i have a 1 amp hour battery and i drain 1 amp out of it for one hour long
i will be at 0% SOC but is that 3.2V or is that 0V??

Im trying to understand how amp hours relates to SOC is the big question here.
If i drain all the amp hours out of an Lithium ion cell, is it at 3.2V or is at 0V??


Thanks
 

nsaspook

Joined Aug 27, 2009
12,747
If it goes into BMS under-volt protection it might be 0V until the condition is cleared by a recharge cycle. Normally about 3.2V is 0% SOC
 
Last edited:

Thread Starter

MikeJacobs

Joined Dec 7, 2019
226
3.2 volts at 0% SOC
Thanks

But what im trying to understand is, if you remove 1 amp for one hour from a 1Ah battery what is the cell voltage?
Is it 3.2V or is it 0V?

Im trying to understand the correlation between amp hours , cell voltage and SOC
 
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