Battery Health

[Kahi]

I was wondering of anyone out there knew a way to test the Health of a Marine Battery. I used a Multimeter to test the voltage after a full charge, and all seems ok, but the Battery lost retained voltage overnight..I know its obviously not in good shape, so I bring it back to WestMarine for an exchange...they pro-rate the value towards a new battery...not a bad deal..but in the process they hooked up my battery to a hand held device that gave a bar graph that apparently showed 'poor' health (only '2' bars of '6' bars, '6' bars being very Healthy)...

What is this machine called?

Can I do the same test using a Multimeter?


Thanks,

Kahi

[Avenger]

That was probably a load tester. It's kind of like plugging a toaster into the battery. By measuring the battery's output under load you can determine how much amp capacity it has.

You can probably simulate the effect somewhat by disabling you engine's ignition system (I'm assuming gasoline here, hold the shutoff in the off position on a diesel) and cranking the engine while measuring the voltage. A charged battery should be at 12.4V or better under no load. It will drop somewhat under load, but if the voltage drops off quickly let's say below 9.5 V under load the battery is tired. Not as accurate as a real load tester, but an easy way to get an idea of what's going on.

[BTH284]

I just like alot of boat owners use to go through a new battery every 2-3 years or so. I have found that keeping the battery hooked up to a good quality trickle charger will get you another year or two as long as you monitor your voltage, electrolyte level and amperage ( a load tester just like you mentioned.)

This is the charger I have had great success with. I am coming up on 2 years with it. http://www.batteryminders.com/batter...o-p-16134.html