Charging batteries with the engine

Redram99 wrote:
Hi all.

I have a 2011 triple e senator 25d. Great motor home. E450 v10.

Just curious, what is the output of the alternator vs the standard converter?

It seems to charge the house batteries off the engine alternator very quickly.
Would that be nearly as economical as running a 4000 Onan?

Thanks.

You must be thinking the quick rise in voltage means they are charged up. In fact that is just the beginning of getting them charged up, which can take hours "depending".

You need a battery monitor to tell what is going on while they are being charged. After you stop the charging, and they have no loads on them either for a while, then you can take their voltage and get an idea of their state of charge ("resting voltage")

The alternator amps to the battery will be reduced by the usual thin wire back to the battery and also from the way the voltage regulator for the alternator works wrt the engine battery. MHs are not all the same, but eg, ours gets about 25 amps to the house battery bank once thing settle from the initial start (takes about five minutes to settle) while the converter can do twice that. The converter only works off shore power or generator, so alternator charging while driving is a good bonus feature.