battery not charging

[rcflyers]

I have a 1988 Johnson 50 electric start, manual tilt. The battery is not charging, How many AC volts should be coming out of the 3 yellow wires under the flywheel to the rectifier unit when the engine is at idle please?

 

[tashasdaddy]

Re: battery not charging

the top 2 threads in the link deal with rectifers, should help you.

http://forums.iboats.com/forumdisplay.php?s=&f=31&page=1&pp=50&sort=lastpost&order=desc&daysprune=-1

 

[F_R]

Re: battery not charging

rcflyer, the problem is I don't think you can measure it with an ordinary AC voltmeter because the frequency is so high. Much different than the ordinary 60HZ. And it varies with rpm changes. A Lot. You should have 12+ at the output of the rectifier (when it is connected). Running without being connected will blow it. Test the stator for continuity and grounds with your ohmmeter.

 

[rcflyers]

Re: battery not charging

Thanks, the stator has low resistance >1 ohm across the 3 yellow wires, and it is not grounded anywhere, I guess the rectifier must be faulty.

 

[rcflyers]

Re: battery not charging

I replaced the rectifier today, still not charging! aaarrgh!

 

[Kevin W]

Re: battery not charging

What RPM are you checking it at?
how much of a charge is on the battery?
At idle the engine does not charge much if at all.
if the battery needs a charge the voltage will not raise much at all when charging.

The charging circuit only produces 6A so charging a half dead battery will take hours.

What is the voltage at the battery before starting?
What is the voltage after starting?

The voltage before starting should be 12.3
After starting it should be more than 12.3 ...it may take a minute or two after starting to rise up.
it might not rise at idle but is should rise some around 2000rpm.
DO NOT over rev it without a load on it.
2 strokes don't like reving without a load.

 

[licketdsplit756]

Re: battery not charging

have you checked to make sure the battery has not got a dead cell in it. is there a fuse there that may be blown.i wouldnt go spending my paycheck on it till i cover the basics first.rectifiers and stators aint cheap. for the most part i have always found it never to be the rectifiers was always the stator .

 

[rcflyers]

Re: battery not charging

Hi , thanks for the help so far, I have replaced the rectifier, battery and charge stator coils for new ones. At idle, the battery reads 12.4 volts, at fast idle it only goes up to 12.65 volts so it proves there is something getting to the battery, just not the 13-14 volts i would expect there to be on a car etc..

 

[Kevin W]

Re: battery not charging

Hi , thanks for the help so far, I have replaced the rectifier, battery and charge stator coils for new ones. At idle, the battery reads 12.4 volts, at fast idle it only goes up to 12.65 volts so it proves there is something getting to the battery, just not the 13-14 volts i would expect there to be on a car etc..

Sounds good to me ...

If your starting battery gets to a full charge it can actually go higher than 14V.
many years of outboards have unregulated charging so at low rpm will have no charge and at max rpm it will have full charge...it will even overcharge a fully charged battery.
Don't be shocked if you see 16V after a long trip or after charging the battery on a charger.