Overcharging

jerrywelds

Cadet
Joined
Oct 19, 2007
Messages
8
50hp 1989 force Has been overcharging for a few months, I finally bought a new rectifier and i thought that would help but it didnt. I have a new battery and also new cables, connections are all good. Was wondering what else could be making it do this. Im not sure but i think i read in the book that it said dont use a maintenance free battery, has anyone else herd of this and could it be the problem. Thank you
 

Frank Acampora

Supreme Mariner
Joined
Jan 19, 2007
Messages
12,004
Re: Overcharging

The engine uses a rectifier, not a regulator/rectifier so it charges at whatever the stator puts out. It will therefore over charge the battery and "boil" off some water while running.

A maintenance free battery usually has more water on top of the plates than a regular battery, so in an auto application, it will last a long time (most likely the design life of the battery) before it ever needs water. If you use a maintenance free battery on your boat, you will not be able to replace the lost water and battery life will be shortened.
 

jerrywelds

Cadet
Joined
Oct 19, 2007
Messages
8
Re: Overcharging

So what your saying is i basically boiled off some of the water that i cant replace and now the motor is overcharging to try and compensate for it. should i buy a maint free battery to start and go from there, what your saying makes sense because the first few months of the battery being new it was ok. Thank you
 

jerrywelds

Cadet
Joined
Oct 19, 2007
Messages
8
Re: Overcharging

Man i dont know what to do i changed thr rectifier again and put in another battery and it still charges at 16.2 volts, im not to worried about it hurting the battery but will it harm my cdi and other motor electronics.
 

Frank Acampora

Supreme Mariner
Joined
Jan 19, 2007
Messages
12,004
Re: Overcharging

Yep! It will charge at 16 volts but there is nothing to worry about. The charging system uses different windings on the stator and only affects battery, starter solenoid, choke, dashboard instruments and lights. 16 volts will not harm them.

The Stator has separate dedicated windings to power the ignition system. It is completely isolated from the charging system except for the common block ground. So, you need not worry about your CD box and coils. They won't blow out and leave you stranded.

In fact, the ignition system acts like a magneto ignition and contrary to a battery ignition where you stop power to the electronics to stop the engine, The ignition in your engine will continue to supply power (somewhere around 200 volts) to the CD boxes at all times the flywheel is turning. Therefore, with the key on, even with a completely dead battery, you can rope start your engine. When you turn off the key, White and blue wires are in continuity to ground and the CD boxes are grounded thereby stopping spark.
 

jerrywelds

Cadet
Joined
Oct 19, 2007
Messages
8
Re: Overcharging

Thank you frank ill be able to enjoy being on it more now that i dont have to worry about getting stuck somewhere...
 
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