cmkworm

I replaced both my starting and stereo battery which are seperated by a switch back in April of this year. My stereo started dying and so I switched it to have both batteries connected. After a short while, the boat wouldn't start. So I jumped it and ran it for a few minutes, shut it off for a bit without anything running. Boat wouldn't start again so I had to jump it again. At idle batteries are only showing 11.6 volts or so. Running it will get up to 12.7 or so. Do you think this is a battery or alternator issue? 496 Mag in an '05 25 Outlaw. If it's an alternator, who makes a higher output than stock alternator? I need it pretty quickly and how hard is it to replace? I'm hoping to do it myself. Thanks guys! Chris.

speicher lane

Are you running a house battery (deep cycle) and a cranking battery or just 2 cranking batteries?

Had a customer a while back had the same issues and said the batteries give up in no time. Looked at the setup - BIG stereo w/ amps and multiple subs in cockpit and cabin and and a pair of CHEAP cranking batteries to start and power the stereo

Alternators generally do not produce max voltage until over 1500 RPM

BajaDan

iTrader: (2)

With the batteries at a reasonable state of charge (not totally flat anyway), you should be seeing 14-14.5 volts across the terminals while charging. The fact that the voltage is higher when charging than when not suggests that the alternator is functioning. Perhaps the voltage regulator is not switching correctly and not allowing the full alternator output to reach the batteries? Best bet is to pull the alternator (it should have a built in voltage regulator, not a seperate one) and take it to a local alternator shop. They can check it out and repair if necessary.

I am assuming that you have checked all the obvious things such as clean and dry terminals and connectors, water level in the batteries etc.

Good luck,

Dan