battery is losing charge slowly during use

Seasonally.boating.jon

Petty Officer 1st Class
Joined
Jul 10, 2011
Messages
283
I have a 2006 60hp mercury Bigfoot on my pontoon. I had the boat out this weekend for 4 hours. We stop on a beach for about 30 min. With the radio on. We decided to leave and I noticed the fishfinder shut off. The gauge was showing about 11 volts. I just installed a interstate battery 1000 cranking amps. Brand new and it the first use. I thought maybe it would charge up on the way to the ramp but it didn't. I'm thinking its the Stator. Why would it go bad and can it be cleaned or something? Thank you.
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
The voltmeter should read something over 13.5 volts with the engine running at cruising speed. If not, the charging system is not working, and no -- there is nothing to clean that fixes this. A new battery may not be fully charged and with the relatively low output of an outboard charging system, a large battery cannot be fully charged in a short run. A 60 HP two stroke Merc probably has a 16 amp alternator. Not much output if you are running a radio, locator and other accessories. If the radio system also has a high power amp, the amp sucks a considerable amount of power. There is more to a charging system than a stator. Regulator, rectifier, and wiring are also part of the system. Does the boat have a tachometer and if so, does it work. A malfunctioning tach is a good sign the charging system may not be working as well.
 

Seasonally.boating.jon

Petty Officer 1st Class
Joined
Jul 10, 2011
Messages
283
Thanks Silvertip. The tach worked fine, everything was working besides the finder shutting off. I don't have much of a radio yet just a marine receiver and 2 5" speakers. The outboard is a four stroke also. So your saying it takes a wile for the outboard to charge a slightly drained battery? It took about 5 to 10 minutes to get to the ramp.
 

procraftguy

Petty Officer 2nd Class
Joined
Jul 7, 2013
Messages
137
If the tach was working id check output of rectifier as stator is probably fine
 
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