Battery charging, has anyone tried it THIS way?

Marcel,

The basic problem with your idea is that it is very very inefficient. No matter how you view it, you are changing electrical energy to mechanical in the motor, then back to electrical in the alternator. Changing energy is never 100% efficient. Deep inside the alternator produces 3 phase ac, but this is converted internally to dc. So you started out with 12V from the battery, ran it through the mechanical stuff and finish up with 12V dc. Along the way you've probably lost much of the original energy.

Once upon a time, before solid state took over from valves, devices called genemotors were used in some battery powered gear to provide the high voltages need for valves. These things consisted (typically) of a 12V motor and (typically) a 250V generator made as a single unit. This is pretty much what you are suggesting. They worked, but were a pain and although designed specifically for the job, were very inefficient.

So, no, not a good idea........... If you must run a 240V TV, use an inverter. At least that's quiet and probably 80% efficient.

Cheers

John