Battery Voltage and Testing

Repair or modification of Boston Whaler boats, their engines, trailers, and gear
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Joined: Mon Apr 25, 2016 5:06 pm

Battery Voltage and Testing

Postby 1985supersport15 » Sat Jul 30, 2016 9:22 am

I early season engine troubles which turned out to be the timer base. Have been out a few times since he repair and engine seems to start up fine initially, but after shutting it off for a few minutes or an hour I have had problems starting. When it's a colder start after an hour or so I prime, choke and lift starting lever. This last time I shut engine off for 5 minutes and then it wouldn't start. Only electronics I had running was color chart plotter.

When I check the battery with a multimeter with engine off it comes in at 12.6 volts. Is that a good number for an interstate deep cycle group 29 or should it be higher?

My plotter diagnostic screen says its registering 11.4 volts. I got this battery in August of the 2012 season.

I am not sure if it's the battery or if the battery isn't charging properly.

When I am on a plane and I check the diagnostic screen on my plotter the voltage ranges anywhere from about 11.4 to 14. I am assuming when it's as high as 14 it is charging.

Any tips on diagnosing this concern would be appreciated. I was thinking about just getting a new battery, but 12.6 volts didn't seem to be low to me.