Battery still not charging enough???

[cx380]

My battery seems to be charging a little but from what I read on this forum its not charging enough. I have a duel battery set up and both batterys are at about 12.25 volts. With engine running it goes to 12.5 to 12.6. My tach also does not work. I put on a new rectifier but the results are the same.

My question is: Is there any thing eles I can do, check, or change before I dish out the 200+ dollars for a new stator? Any advise would be very helpful

Thanks Jon


Engine: 1988 88hp SPL Evinrude

 

[HighTrim]

Re: Battery still not charging enough???

It is easiest to check for 12-volt power and proper ground first. A volt-ohmmeter or 12-volt test light are great tools for this procedure. Simply ground the meter or light, turn the key on and touch the positive probe to the purple wire on the back of the tach. You should see 12 volts indicated on the meter, or if you?re using a test light, its bulb should illuminate. Reverse the leads to check for proper ground, or use the ground wire on the tach to ground your meter or test light.

If either the power circuit or ground is the culprit, you can repair the problem and the tach should work fine. In a no-power situation, see if your tach has an inline fuse. These often blow due to constant vibration. After inspecting for power and ground, if it still doesn?t work, it?s time to check the signal-input source, or the tach itself.

A simple way to determine if the tach is bad is to use another tach. Some shops will have a tach ready with alligator clips just for this, ask them and see if they will let you borrow it, or borrow one off a buddy.

In the event you don?t have access to a shop tach, you?ll have to refer to the manual to check the signal source. The signal is a pulse-positive output that?s provided directly from the stator assembly through the rectifier. A peak-reading voltmeter set to ?positive? and the lowest volt scale will enable you to read any voltage output (on this circuit) from the stator.

Check the procedure and specifications for your engine, since the inspection point, procedure and wiring are not the same for all outboards. In addition, your ohmmeter can be used to check the continuity of the stator windings, as well as the integrity of the rectifier diodes.

I would probably start by cleaning and tightening all wiring connections regarding the battery. Dont just look at them, make them shine! Do a voltage drop test to check for faulty wiring segments. If you need help with this let us know. After that, test the stator as per your manual.

 

[F_R]

Re: Battery still not charging enough???

If you really want to know if the alternator is putting out it's rated charge current, get yourself a low reading DC ammeter. Those 60 amp things they sell for cars are pretty useless on a 6 amp system. You probably have a 6 amp system on that 88, so if it is putting out 6 amps, that's all it can do and everything is working. You would insert the ammeter in the output wire on the rectifier.
EDIT: I'm thinking maybe Radio Shack for a meter thet you can use as a temp test hookup.

 

[cx380]

Re: Battery still not charging enough???

The tach is geting 12+ volts. How do I check the tach signal?
Also how do I check if the stator is putting out enough amps? Its a 9 amp stator and I have a top of the line fluke multimeter. I have a Selco manual but it does not mention anything. I'll be getting a OEM manual shortly. My battery conections are very clean, tight, and covered in DC4.

 

[F_R]

Re: Battery still not charging enough???

I just told you. You measure amps with an ammeter. If it is putting out what it is rated for, the stator is OK.

 

[CharlieB]

Re: Battery still not charging enough???

First and foremost, install a battery selector switch and DO NOT USE BOTH BATTERYS.

Most outboard charging systems are minimal, at best, and WILL NOT charge two batteries at once.

Remove or disconnect one battery and retest, you should see improvement in your readings.

Remember, these systems or only to keep the starting battery alive, and a couple of very light loads such as running lights and a depth sounder.

 

[Vic.S]

Re: Battery still not charging enough???

To clear one point the stator does not "put out amps" it generates an EMF, measured in volts, the current that flows (in amps) will be proportional to the volts and inversely proportional to the total resistance of the circuit, including the resistance of the stator. The magnitude of the emf generated in volts will be dependent on the speed (rpm of the engine)

Doing what F_R suggests will tell you the current that is flowing into the batteries. but it will depend on a number of factors not least of which is the speed of the engine. At idle the volts generated will probably not be enough to charge the battery at all but as the revs are increased you should see the current increase. At high revs you might briefly see something approaching the max rating of the stator if the battery is flat but it will rapidly fall as the battery starts to charge.

You say you have a dual battery system. So you really need to either check the current flowing into each battery individually or tap into the wiring before the charge splitter and measure the total current.

How is the charge split between the two batteries? That could be the cause of the problem if there is in fact one.


Personally I would feel inclined to disconnect the stator from the rectifier, just two yellow wires if I have done my research correctly, and measure the AC volts directly from the stator. At idle it will be quite low but as the revs are increased it should rise to well above 12 getting to 14 maybe even 16 or more at max revs. (That's between the yellows not from yellow to ground)

I would then reconnect the yellows but disconnect the output wire from the rectifier (red?) and measure the Dc volts between there and ground although with a new rectifier fitted that should hardly be necessary.

It would be informative to connect just a good load onto the red, a head light bulb, or even two to ensure that you can get something like the rated maximum current. (You should be able to light 100 watts of bulbs at full brightness from a 9 amp stator)


BTW With only 12.25 volts showing your batteries are half discharged at least. You should take them off and recharge them as soon as possible as leaving them in that state will dramatically shorten their lives.