niconiconi on Nostr: How to check how much energy is left in a battery? Everyone: Measure the open-circuit ...

How to check how much energy is left in a battery?
Everyone: Measure the open-circuit voltage. Monitor discharge current over time and compare it with the calibration curve.
Flooded lead-acid users: Just open the cell and see how much unreacted materials is physically still there. Be careful not to spill the sulfuric acid.