Thinking of going to AGM since with the current battery location there is no way to check fluid levels or top off if necessary. The existing AC charger has a AGM setting, but what about the engine driven alternator?
Bob
AGM and Alternator
- km1125
- Admiral

- Posts: 3657
- Joined: February 28th, 2017, 6:04 pm
- Has thanked: 81 times
- Been thanked: 1114 times
Re: AGM and Alternator
The difference between AGM and a flooded battery is so insignificant it won't matter if the battery is charged via the alternator or the charger. The biggest difference is in equalization voltages and times and the alternator doesn't even perform that function. That function is important for batteries that don't get exercised regularly and starting and running the motor does precisely that.
-
Viper
- CYO Supporter

- Posts: 6266
- Joined: July 10th, 2015, 9:58 pm
- Vessel Info: 1989 Carver 3807 Aft Cabin
- Location: Ontario, Canada
- Has thanked: 475 times
- Been thanked: 1791 times
Re: AGM and Alternator
You can address charging AGM with the alternator by adding a smart multi stage regulator. That is the best option and should be practiced more IMO, but they aren't cheap. Really comes down to your boating style though. If you're running for hours/days, a smart reg is the way to go. If you're just going around the corner all the time, it's probably not worth it.
- bobwhorn
- Deck Hand

- Posts: 63
- Joined: February 18th, 2023, 1:18 pm
- Vessel Info: 1989 Carver Santego 3867. Repowered with Cat 3116s in 1993.
- Location: Texas
- Has thanked: 3 times
- Been thanked: 1 time
- Contact:
Re: AGM and Alternator
I still have a Balmar external regulator somewhere. I guess I would have to get the alternators modified for an external field connection. The AC Prostar chargers do use the same settings for AGM and flooded.