? on 3 bank on board chargers.

[croixflats]

I have a three bank onboard charger. The question is it really safe to keep the charger on the starter battery. I am going on my third stator on my Yamaha 150 and I'm trying to pin point whats burning my stator out.

I know jump starting a boat can burn a stator out just wondering if the constant charge even when it switches over to maintenance cycle can burn out a stator. My mechanic says charging can possibly burn out a stator.

But I would think with the ignition off it would break the circuit to the moter.

These stators are exspensive at $400 a pop. Luckily the last stator I put in was used,$200, so I'm hoping thats the reason its bad.

[jeffreyd]

one thing you can do is to feel the area around the engine when you are charging the battery and see if it warmer than other areas on the cold engine. if that is the case then it is leaking thru and you have some other issues. this is what happens when a diode goes out in an altenator, the case will feel warm on a cold engine.

[croixflats]

Thanks jeffrey, I'll feel around the engine tomorrow.

These electrical issues are a pain in the rear. I had every major electrical component sent in to get tested and they all came back positive for working, even the stator that was bad.

[marine_man]

Wow.. that's pretty unusual to be on your first, let alone second and third stator on a yamaha.

Your charger should be safe... I guess I would double check the polarity of the charger (actually check it with a multimeter) to be sure that it's not reversed for some strange reason.

marine_man

[PerchJerker]

I leave my on-board chargers plugged in almost constantly and have never run into any problems like that ..... I've never even heard of any problems like that. Good luck getting it figured out.

[kg2]

marine_man, have you seen battery chargers put out a negative charge? I am just wondering, and I have a theory on what is actually happening to the battery that is negatively charged. (I don't think it is a charger issue.)

[norma]

Altenators put out AC current, There is a bridge rectifier that converts ac to dc current. The voltage regulator regulates how much current the altenator puts out.

Sounds like you have some stray voltage causing your problems. Start by taking a voltmeter set to dc volts, and take one lead,place on the battery negative and the other lead on the engine, should be 0v if there is voltage present you have a short. To locate a short, set one lead to the battery positive, the other on the positive lead on your accesories, if you see more than 0v that is how much you are leaking there. Do the test with the engine both off and running.

Another check to do is with the motor running, set the voltmeter to AC volts, put the leads on the positive and negatiive of the battery, Any ac voltage present is caused by a leaky rectifier. There are three positive and three negative diodes in the rectifier, if only one or two are good, the rectifier willl test ok, the voltage regulator regulates dc voltage, on the output side of the regulator. If voltage is low, the regulator increases voltage to the stator. If the rectifier has bad diodes, stator voltage could be 30v + while output is 13.1, the remainding voltage is converted to heat. The rectifier will also block any voltage from the battery charger to the stator, protecting it.