Voltage Regulation

[Doug]

We receintly finished spending 2 months in the Bahamas on our 32+2 CB.
Toward the end of the trip, we started having lots of battery problems. Once we got home, I checked the batteries and the 4 house batteries were bad. All are AGM batteries and most had a "swelled up" look, which is a sign of overcharging. We have a Zantrax true charge charger, and all the settings on it are correct. This leads me to beleive the alternator is putting out too much voltage for this type batteries. The new AGM batteries I purchased yesterday have a sticker on them saying "Float Charge 13.5 to 13.8 VDC at 77 degrees F. " The engine is a Cummins 370 HP Turbo.
The alternator is a Delco.

My question is - have any of you installed any tpye of extenal voltage regulator and are you satisfied with it?
Thanks,
Doug

[joe.baar]

Our batteries normally float charge using shore power that comes through the Freedom Marine 20 inverter+Xantrex basic remote panel. Last year we replaced 4 badly swollen and cracked lead-acid batteries with 2 Optima Group 34D Ms. This relieved us of having to water the batteries regularly but we noticed the inverter as shown on the Xantrex panel was applying very high voltage to both banks - up to 14.9 volts at times. As a result I now keep our shore power connection unplugged under normal circumstances. We have a Yanmar 6LPA and offhand I forget which alternator, but the issue has not been with the power plant but rather with the inverter.

[N4QC]

My multistage battery charger is a Xantrex Truecharge 20+ amp charger. The instruction book covers the 20 and 40 amp chargers.

The charger has a temperature switch which is used to select appropriate charging voltages depending on battery temperature. There is another switch
which allows for the selection of battery type - Flooded, Gel or AGM.

In as much as you are in the Tampa Bay Area, I would recommend the HOT setting for battery temperature (all year). In my case the output voltage for absorption, Flooded,
mode is 14.0 volts, and 13.1 volts for float mode. Same specs for an AGM battery...

The book further recommends that Hot be selected if in doubt as to what to select or if you leave the charger connected for an extended period of time.

77 degrees is a typical reference point for marine calculations when dealing with heat. Tampa Bay's 90 degree plus environment does a number on fuel and cooling values. Perhaps you can find a temperature charge rate performance chart covering various degree values from the battery manufacture.

Make sure that the battery charger has adequate ventilation...

Hope this helps...