How Do You Calculate Battery Bank Total Amp Hour Capacity?

[mitiempo]

Originally Posted by Dave Lochner

State of Charge generally refers to the amount of battery capacity that is available to use. If we start with a battery with 100 amp hour capacity and draw 10 amps for 5 hours, we now have a battery with 50 amp hours available or a 50% SOC.

Not quite, you are forgetting Peukert. When a battery is rated at 100 AH it is based on the 20 hour rate. For a 100 AH battery that means a 5 amp draw over the 20 hour period.

If you draw 10 amps from the same battery you will have a lot less than 100 AH available. The reverse is also true - if you draw 2 amps from the battery it will have a larger capacity than 100 AH.

[StuM]

Originally Posted by mitiempo

Not quite, you are forgetting Peukert. When a battery is rated at 100 AH it is based on the 20 hour rate. For a 100 AH battery that means a 5 amp draw over the 20 hour period.

If you draw 10 amps from the same battery you will have a lot less than 100 AH available.

Which incidentally is another good reason to oversize your battery bank.

The bigger the bank, the higher the Amps you can draw without the Peukert effect reducing your rated Ah.

[mitiempo]

Originally Posted by StuM

Which incidentally is another good reason to oversize your battery bank.

The bigger the bank, the higher the Amps you can draw without the Peukert effect reducing your rated Ah.

Or with the same amp draw a larger bank than its 20 hour rating.

[captrick2014]

Simple @ less complex, battery amp hours divided by half.