AGM for start, and Wet for house?

[witzgall]

Does anyone out there use an AGM for their starting battery, and wet cells for house? If so, could you share your charging system specifications? I know Xantrex makes a few chargers that can be programed for different chemistries, any others?

Chris

[Rick]

There are a few AGM brands which will tolerate up to 15V like the Optima. Although the wet float settings are not ideal for an AGM it will not be bad either, especially since one can opt to merely throw a disconnect switch or a settable disconnect solenoid to place the start battery out of the shore charger circuit.

The easiest thing to do, therefore, is install a good AGM and not worry about it because it is not being used for deep discharges and will not charge accept much current when the engine is turned off.

[witzgall]

Thanks Rick - The Optima was the start battery that I was thinking of in this scenario, so I just might go this route. I think the smaller Optima red top would be suficient for our 18hp Volvo.

Chris

Originally Posted by Rick

There are a few AGM brands which will tolerate up to 15V like the Optima. Although the wet float settings are not ideal for an AGM it will not be bad either, especially since one can opt to merely throw a disconnect switch or a settable disconnect solenoid to place the start battery out of the shore charger circuit.

The easiest thing to do, therefore, is install a good AGM and not worry about it because it is not being used for deep discharges and will not charge accept much current when the engine is turned off.

[Alan Wheeler]

My setup is exactly as you have asked. AGM for Start duty and FLA for House. The charger is connected to the house bank only. The Alternator is connected to a charge splitter, so normal "after start" charging is taken care of by the Alt. Then for long periods, like Winter, I have a solar panel and charge controller that is connected to the start bank only. This keeps tickling them over the winter months. But these AGM's will happily go for a year with little decrease in current, so I don't really have to have the Solar panels. They were there, so I made good use of them.