You are kinda right, but if you are drawing more than the alternator can supply eventually you will end up with a dead battery.Originally Posted by podcake
The alternator has to keep up with all the stock equipment + keep the stock battery charged. Then you add to the work load by adding amps computer or what ever. Then an extra battery to charge. You must have an alternator that can put out enough to take care of all that, pulling more power that the alternator can supply can only result in a battery that is not being full charged.
It's the cake having/eating thing.