Charging rate on Evinrude

[chdabren]

Can anyone tell me what charging voltage I should have at my battery with my engine running? I have the 'Rude 85 hp (85493-b) and I think I may have a stator/rectifier problem. My battery, with full charge, is at 12.86 volts. Engine running, DVOM attached to battery, voltage is only 13.26 at best. How do I tell for sure that the stator/rectifier are even working? Is there an ohms test I can do on it? If so, does anyone know the specs? I'm not sure what amperage my stator should be. I thought that as long as the battery is hooked up to the motor, it should charge the battery just like on a car. Am I wrong? Is there something I haven't hooked up? Something else I need to wire up? I'm definately not seeing the voltage I'd expect at the battery (engine running). Or am I missing the whole big picture? Maybe I'm expecting #'s that won't exist. Anyone that can share information on this subject or ideas on what/how to check things would be great. I've looked for replacement stators online but can't find the correct part #. Only part #'s I can find are 581225 (stator) and 582307 (rectifier), both #'s are original superceded Evinrude part #'s. Thanks to anyone who can help me.

Chris

 

[emdsapmgr]

Re: Charging rate on Evinrude

Your thoughs are pretty much on target. Your model probably has a 6 amp stator. The stator has two different coil windings. One set for running the ignition, the other for charging the battery. Most engines today use a volt gauge to the battery, rather than the older models which used the ammeters. After starting, the charger should put out more voltage than normal battery voltage (12.4-12.6.) The rectifier on that engine is not also a voltage regulator, so you could eventually see battery voltage rise to 14.5-16 volts the longer you run the engine. On these models you do need to be somewhat concerned about the overcharging, so just check the battery water level through out the boating season. (or just run the high output sterero.) The rectifier also drives the tach. If you have odd tach readings, it can be an indication that the rectifier is questionable and that the battery may not be charging properly. If you go to the Bombardier website epc.brp.com, you should be able to find the original parts lists for your engine.

 

[F_R]

Re: Charging rate on Evinrude

Unless you have the optional at extra cost 12 amp alternator kit, your alternator puts out a maximum of 6 amps. That is plenty unless you have a lot of accessories (like added power tilt/trim). From that 6 amps you have to subtract any load, (such as a radio). So if you have 6 amps charging, minus 3 amps load, that leaves 3 amps to charge the battery. Still enough to keep it charged.

OK so where am I going with this? Simply saying that you do not have a great amount of juice to work with. Your alternator is working, as evidenced by the increased voltage when running. It takes time for the voltage to rise to higher levels, if it is going to. Even then, more people complain of overcharging rather than undercharging.

Your stator is just fine. They don't go sort of bad, only good or bad. (The ignition part can go sort of bad, but let's not go that way and only get confused).

The rectifier is a full-wave bridge rectifier. That means it uses both waves of the AC stator output. It is possible for a diode in the rectifier to be open, in which case it would only work on one half of the AC output, giving 3 amps instead of 6. Let me hasten to add that it is more likely for the diodes to fail in the shorted condition than open.

Bottom line is if you are in doubt, you can use a suitable ammeter to check the alternator output. Or you can do a rectifier test. Test all four diodes in the rectifier in both directions.

My prediction: There is nothing wrong with it.