Battery life?

[Big Mac]

I have a 22' cruiser, the Mary Ellen. It has twin 40HP Hondas' with the shore power option which includes a charger. I keep it powered up during storage. I recently decided to look at the water level and found it to be low in several holes. I added water and thought I would have the batteries checked at Les Schwab. They both checked out as good batteries. I have 76 hours on the engines and the boat will be 4 years old this July. I am wondering how often others have had to replace the batteries? They are deep cycle batteries.

 

[Larry H]

I have been getting 3 to 4 years on a set of batteries. I have used Interstate Batteries and West Marine. The Interstate batteries were better and lasted longer. I now have 4 years on the current set of West Marine batteries and they have lost about 25% of their new capacity. I won't buy any more batteries from West Marine.

I use a digital voltmeter to check the voltage and only charge during storage off season when the resting voltage gets down to 12.2 volts.

 

[Chuck S]

I've not found it necessary to charge the single Interstate battery on our boat at all, the battery stores more than enough charge to start the Honda 50 and the alternator quickly replentishes any amp hours used.

Unless you're in the tropics, dry cells is a sign of overcharging the battery. I charge our boat and camper batteries once a month during the off season. If we dry camp I hit the camper battery on our return. With the 10a alternator on the Honda 50 external charging hasn't been needed on the boat.

But, our mooring is the trailer so the bilge pump isn't running day and night, nor have we anchored out and run the anchor light all night! One of those small jump start battery packs will jump either of our cars, so I've no doubt it'll spin the 50 if needed.

-- Chuck