[M] Alterpower alternator charging control switch

[Clarence L.Snyder]

The charging system outputs anywhere up to 14.6 volts into a fully
charged battery depending on vehicle and conditions. Under optimum
conditions the at is putting out about 15 amps - to run itself,
ignition, and fuel pump. Say 20 to be generous. 20X14.6/.8 (80 %
efficiency)=365 watts. That's getting pretty close to 1/2 HP. I think
the original poster slipped a decimal point!

As for power loss due to reduced voltage, that, my friend is a red
herring. If your battery cannot maintain 12 volts for at least 10
minutes with a 10-15 amp draw (remember, no alt field) you better get a
new battery. Dragsters run with no alt at all - just the battery, even
with big MSD boxes - and they use piddly little batteries.