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I am trying to judge state of charge for a my lifepo(TS90Ah,38 cells, ~120vpack) batteries and looking at the graphs from thundersky I am having issues....

I basically want to know the top voltage (100% charged) and the bottom voltage (70% discharge) range for the 90Ah units.

The Thundersky docs show that these voltages (working off a 3C discharge) are from 3.2v (100% charged) to 3.1v (30% charged). This sounds really quite wrong. Am I being a graph retard???

I thought that after a full charge the cells should start at around 4.2v ish and then slowly drop down to 2.5v (around 70-80% discharge).

If the voltage curve changes for different 'C' discharge rates does anyone have use a formula to calculate more accurate pack charge percentages?

Can anyone provide a graph of a cells discharge please?

Thanks!