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jay_manikandan 10-17-2007 03:25 AM

Battery Remaining Capacity

I am writing an application to find the current battery capacity in the driver level.
My board has Li_Ion battery.

I can get the following parameters from the battery driver:
1) Voltage
2) Current
3) Temperature.

I have to find out the remaining battery capacity with the above params.
I read some article which says we have to consider 1)temperature derate factor and 2)depth of discharge to calculate the capacity with accuracy.

Please help me in this regard.

I have gone through the posts made in this forum. All the posts are
discussing about /proc/acpi filesystems.
But my case is different.


Findus 10-17-2007 03:45 AM

Maybe you could specify in what regards your case is different? I can't help you, as I am not much of a programmer, but that information might help some one who can to give you more specific help.

- Findus

jay_manikandan 10-17-2007 04:01 AM

I have to find out the remaining battery capacity without /proc/acpi file system.
I have to use the following parameters to calculate the battery capacity.
1) Voltage
2) Current
3) Temperature.

I read in an article to find the current battery energy in Watt-Hours.

E = C * Vavg * (tempdefactor/100) * (depthdischarge/100)

tempdefactor -> Temperate derating factor
depth discharge -> depth of discharge.

Can i use this formula to calculate the current available energy of a battery?
If so, what value i can use for tempdefacor and depthdischarge?
Is there any spec or tables to find out these values based on temperature and ageing?

Hope am not confusing you.

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