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Posts: 28
Location: Sauk Centre MN | I've noticed that my starting battery isn't charging while the motor is running. I've got 3 batteries in the boat. 2 for the 24v troller and 1 for starting and accessories (two graphs, livewell pump, bilge, lights. Sunday, my dad and I were out for about 3 hours trolling for northerns (he can't cast but loves to cut out y bones) the whole time with the big motor and I had charged the starting battery fully the night before (since it seemed low last time out when I only ran the motor for about 20mins). After about 2 hours my locator was flashing a low voltage warning. The warning is set at 8.5v. We had a couple in the livewell and I left the aerator/pump on for about 30mins (forgot about it). I may be wrong but shouldn't the motor running at idle the whole time keep that battery charged? Also, the starting battery is in its fourth season and so I'm picking one up today. I don't think I'll be on the water again for a couple weeks to test it with a new battery and need it to stay charged when I do. So assuming the old stereo I put in this spring isn't causing a draw, I've got three main questions..
1. Should I have all of my accessories running off the starting battery?
2. If the battery is good, shouldn't it stay charged if the motor is running all day?
3. How do I test the charging system if the battery is fine (i.e. replaced w/ new)?
Thanks for the help,
Dan |
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Posts: 1087
Location: Hayward, WI | Normally all acc run off starting battery. Should stay charged with motor running. Motor should put out 14.4 volts to start battery when it is running. |
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Posts: 5874
| It's possible that the stator is bad on the motor. Not sure what this motor has for a regulator or bridge. Best way to tell if there is a problem with the charging system is to get it to a dealer to test the output.
Your stereo definately is a drain on the battery.
At idle, the output of the charging system is not as much as when the RPM's are up, so it may only put out enough to run the motor, and not charge the battery. But it sounds like the motor is not charging at all, and draining the battery.
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Posts: 2752
Location: Mauston, Wisconsin | Shep is right it could be a bad stator or it also could be the rectifier/regulator. I had the same issue when I bought my used 1989 Skeeter. Now I know why he had a charger on it when I arrived for the test ride.
Does the tachometer work? The tachometer on my Skeeter didn't work when I bought it. The tach signal on my 1989 Johnson 150HP comes from the rectifier/regulator, its actually the stator output pulse's. If the tach is not working it's likely one of the above. It also could be a bad connection in the charging circuit.
I doubt that Johnson/Evinrude changed to much over the years from 1989 to 1994. Both the stator and the rectifier/regulator on my motor are under the flywheel on top of the motor. The rectifier/regulator is water cooled. It's not something the average home handyman would want to tackle- you need a gear puller to pull the flywheel off and a FT/lb torque wrench to re-torque the flywheel retaining nut when you reassemble it.
If you really want to tackle this yourself, go buy the service manual at your local Johnson/Evinrude dealer. Shep's advice is probably spot on- you probably should take it to your local Johnson/Evinrude dealer.
I'm on my second rectifier/regulator. Why? Lightning struck a tree ~ 30 feet from my house - the boat was parked on the garage entry apron. It took out the entire electronics in the motor - ~$800 later I had a operational boat again. Fortunately I had removed both my Humminbird and EagleII. I'm a trusting soul, but not that trusting. Now, I remove them anytime the boat is parked, even at the dock in Canada.
Lightning bites! I know what some of you are thinking - shouldn't the rubber tires have protected the boat? No! The lightning didn't strike the boat itself. it was the magnetic field generated by the lightning strike. The magnetic field induced a very large voltage spike in the boat wiring system, and that took out my engine electronics. Now I'm hoping lightning doesn't strike the same spot twice. But, that's also wishful thinking.
BTW: The service manual for my engine says that the alternator test has to be run at ~4500 RPM's to properly check the rectifier/regulator output.
Good luck!
Al |
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Posts: 28
Location: Sauk Centre MN | Thanks for the replies. I'm a pretty good DIY auto mechanic but I'm very nervous working on my outboard. (I can always borrow someones truck to go fishing). I honestly haven't looked at the Tachometer all year. I guess that's what fancy electronics does to a guy. Old gauges get ignored... I'll do some testing and hold off on the battery for now. I'll let you know what I discover. Where do you buy your parts if you do DIY repairs? I was thinking of these guys. http://www.marineengine.com/ I really don't trust my local dealer. |
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Posts: 333
Location: menasha wi 54952 | Your battery on a motor that old will not charge at low idle. You will need to up the RPMs to get the stator on the motor to put out more than 12.4 volts. Does your locator/graph display voltage? You can monitor how much voltage your outboard is putting out while at idle vs. higher RPM. Also, your battery at full charge without any load, should read about 12.2 - 12.4 volts. If it is less than that, lets say 11.8 or less, the battery is going bad. You may have an open cell that is allowing you to charge but no reserve to run for long periods of time. Just went through this with mine. Ended up being a bad battery.
MR |
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Posts: 2752
Location: Mauston, Wisconsin | Both of us, (Shep & myself) are electrical engineers, we wouldn't steer you wrong. If the tach is not working, you've got a charging problem. A fully charged 12V battery at rest w/o load should measure ~12.5 to 12.8V - 12.7V is typical. As it gets older this will drop somewhat.
Your engine has to charge the engine DC system and battery at idle. Once its started, the engine doesn't really need the battery. I've literally ran my 1989 Johnson 150HP at idle for multiple days when I'm up in Canada and just like you, I have all my sonar electronics, dual live well pumps, bilge pump, marine radio and stereo, running lights on my starting battery.
The link looks pretty darn good, thanks. Any parts you'll need are found in the "Ignition Section" - If you really want to tackle this DIY, you need to first get a factory service manual for your motor. Usually $ well spent, I have both the operators manual and service manual, I keep them in the boat w/ some basic tools. You need the motor ID number & serial #, that's important to both make sure you have the right manual and that you are looking at the correct parts list.... The service manual will have precise checks to test both the stator and the rectifier/regulator. You will need a digital volt/ohm meter to troubleshoot the charging system. If you need more help or if you get to the point of pulling the flywheel send me a PM with your phone number & I can walk you through the process......
Good luck.
Al
Edited by ESOX Maniac 6/20/2012 12:49 PM
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Posts: 333
Location: menasha wi 54952 | I am also an electrical engineer and a master electrician. I agree it is a charging problem which should be diagnosed rather easily with any voltmeter. I have seen some funny boat wiring things and would not rule out anything. Good luck. |
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Posts: 5874
| Union electrician? |
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