12 volt Electrical Battery Problems. Where is all the power going?

[noelex]

The key point for people to understand is that the capacity of a battery reduces quite significantly when discharged at higher currents than the C20 rate; you can't just divide capacity by current and get an accurate run time.

Yes I think this is an important concept to understand.

With small currents relative to the battery size the effect can be ignored, or may even result in the battery having a higher capacity than rated. However, Peukets equation is sometimes ignored when the effect is quite significant, as this example illustrates. The expected run time drops from the 3.4 hours that the simple calculation suggests down to arround 2.5 hours

 

[roaringgirl]

Yes I think this is an important concept to understand.

With small currents relative to the battery size the effect can be ignored, or may even result in the battery having a higher capacity than rated. However, Peukets equation is sometimes ignored when the effect is quite significant, as this example illustrates. The expected run time drops from the 3.4 hours that the simple calculation suggests down to arround 2.5 hours

The result is 'your batteries are behaving as expected, if not slightly better than expected. Nothing is stealing the charge'.