Hi everyone,
I want to measure the lead acid battery level( percentage of charge) through the Arduino. its easy to find when the circuit is open. problem is that when i connect the load battery voltage is drop and i failed to calculate the exact battery level. I want to continuous power provide the load simultaneously want to measure battery voltage. help me how can i do that.

 

State of charge doesn't give an exact indication, even when the battery isn't loaded.

https://batteryuniversity.com/learn/article/how_to_measure_state_of_charge

 

You could use one of these Watt Meters betwean the battery & the load. If you know the battery Ah capacity, just subtract the Ah on the meter from battery capacity & it will give you how mutch is left in the battery. That's what I use & they are not expensive on E bay.

 

It's good but I want the circuit diagram. Which i want to embedded on my system.

 

State of charge doesn't give an exact indication, even when the battery isn't loaded.

https://batteryuniversity.com/learn/article/how_to_measure_state_of_charge

Yes. Any another method that give me accurate result?

 

I think it would be completely arbitrary with a lead acid battery. AT what voltage and at what current will you decide the battery is discharged? It would have to be load dependent. And what you feel good with. To be super geeky about it........you would have to calibrate to each battery.

 

Coulomb Counting -

http://www.analog.com/en/products/power-management/battery-management/coulomb-counter.html


Regards, Dana.

 

Coulomb Counting, widely used in LapTops and Tablets as well.

To measure battery esr -

https://batteryuniversity.com/learn/article/how_to_measure_internal_resistance

Regards, Dana.

 

Coulomb counting, as danadak suggested, would be the way to go.

 

Coulomb Counting works well in LI-ion batteries but with lead acid there are first order effects like the Peukert's law that renders just Coulomb Counting ineffective for varying loads.

https://batteryuniversity.com/learn/article/bu_503_how_to_calculate_battery_runtime