Battery Life on a portable

[Guest]

Does anyone know the formula that is used to calculate battery life? I’ve
noticed that when there are two batteries installed in the computer, the
operating system averages the percentages available which seems incorrect.

Example:
Battery #1 26%
Battery #2 8%

Total battery power remaining: 16%

I see the issue because the title says “Total battery power remaining:†and
this is not the case, this is the average batter power remaining.
Additionally, if you have your alarms and actions set in your power
management, the averages bring you closer to the alarms and triggers. The
total battery power remaining should be Battery 1 plus Battery 2 and should
be 34%.

Please advise

 

[Bob I]

The laptop manufacturer uses whatever algorithm they deem appropriate.
It isn't a function of Windows.

 

[David Cheatham]

Does anyone know the formula that is used to calculate battery life?
I’ve noticed that when there are two batteries installed in the
computer, the operating system averages the percentages available
which seems incorrect.

Example:
Battery #1 26%
Battery #2 8%

Total battery power remaining: 16%

I see the issue because the title says “Total battery power
remaining:†and this is not the case, this is the average batter
power remaining. Additionally, if you have your alarms and actions
set in your power management, the averages bring you closer to the
alarms and triggers. The total battery power remaining should be
Battery 1 plus Battery 2 and should be 34%.

No it shouldn't. That would imply that when both are at 100%, you have
200% total battery life remaining, which would obviously be inane. It's
not 'average battery power' or 'combined battery power', both of which
would be completely meaningless, it's 'out of the total combined juice
in the batteries, how much has been used'. That's what 'Total battery
power remaining' means.

And you can't just average two batteries together to get the right
amount anyway unless they are exactly the same size. If you have a
battery with three hours, and another battery with one, and the second
battery is completely dead and the first completely charged, you have
75% battery life remaining, not 50%, and certainly not 100%.


However, your batteries appear to be roughly the same size, as 8 and 26
average to 17, which is within rounding error.