Now that our boat is in the Chesapeake Bay and our use pattern is totally different than it was when we lived 5 minutes from the boat, we spend a lot more of our cruising time on the hook than we did when we lived in Long Island. A recent thread about Inverters and batt charging got me wondering...

Anyone have a rough (or accurate) idea of the charging rate of a standard type batt charger vs the charging rate for the engine/alternator on the same batt bank?

I'm specifically interested in the 32v banks and the original Lamarche Charger. I'm assuming that the charge rate of the main eng alternator is higher than the charger delivers but I don't know that for sure and don't have any manuals, etc here in Mexico.

So what will charge the batts faster, the charger (genny providing a/c) or the main engine spinning the alternator. Further, as someone suggested, will the inverter (Outback) charge the batts faster than the LaMarche batt charger if the inverter is connected to do so (mine isn't)?

I'm asking this because as the admiral and I were discussing our upcoming boat cruise, we recalled that the last time we were out on the hook, the batt bank supplying inverter power did not fully recover after a couple of days. It supplied the needed a/c power with no problem but after doing this for this period and running the genny for a couple hours a day to charge, the batt bank would not spin the engine for starting on the third day. The parallel start switch, of course, is there for that purpose and worked fine.

So obviously the batts weren't being completely recharged and the genny needs to run more than we were running it per day OR a more "powerful" or efficient charger needs to be involved.

For any of you using the 32v oem system for inverter power - how long do you have to run the genny per day to top off the batts charge-wise. I realize this is totally dependent on your inverter loads, your charger and your batt AH capacity but a rough idea would be helpful.