Seafever
Well-Known Member
I think the charger on my Merc Outboard limits out at 15 volts....I use an AGM battery (Absorbent Glass Mat). I saw on the net you are never supposed to use a charger that goes over 14.4 volts or it will damage an AGM. And never supposed to use an old non-current-limiting automotive charger. My battery I bought from CanTire in 2007 and it is still going good (Nautilus Spiral Cell)....but that's 6 years and I fear it may die from old age. I have used it last year on my current Merc and it seems to be o.k. so far........holds a charge when stored for months..... Was just wondering if the onboard Merc charger will eventually kill it because it's a tad higher than recommendation? I like the AGM type batteries because they resist boat vibration so well....I don't get very long life out of any marine wetcell battery. No outboard-engine built-in chargers go below 15 volt max as far as I know.