How to estimate state of charge (SOC) in open circuit voltage for battery ?

I want to estimate soc from open circuit voltage method,how can i do that?

is there any formula for that or equation?

using loop-up tables we can map voltage to soc,if i am not wrong?

Hello,

Well maybe if your table is a history of the same battery, but it should be taken into account that the aging of the battery will promote a greater internal resistance, and with this when applying current, the voltage will be dropping even more than when the battery was new.

Much of the electronics does not even offer a real remaining remaining percentage of charge, even the smart phones seem to suffer to deliver a true value.

The large differential of a notebook battery to a hand lantern battery (18650) is in the presence of a charge controller, which will be monitoring the recharge, and when the discharge does not occur as intended,

Ie when the battery has not been charged, then the controller notes this deficiency as the health of the battery, say the battery is new, its health will be 100%, but as the battery no longer holds the charge, or the internal resistance increases, then health is falling.

Example of laptop battery health

There's a pretty good overview article on this at this link: https://batteryuniversity.com/learn/article/how_to_measure_state_of_charge

For some battery technologies (lead acid in particular) one can get a pretty good idea of SOC from voltage, perhaps also with a temperature compensation.

Battery technologies with relatively flat voltage discharge characteristics render SOC from voltage not very accurate. Laptop and mobile phone battery monitoring (LiPo batteries) is done primarily via Coulomb counting, that is, monitoring the integrated charge and discharge current of the battery to estimate the state of charge. Voltage monitoring of LiPo batteries is done to prevent excessive discharge, but is a poor indicator of the state of charge until the battery is near full discharge.

Why create another thread for this? http://forum.arduino.cc/index.php?topic=575937.0