battery not charging?

[cheeksf16]

I have a 20' pontoon boat with a Mercury 60 hp efi Bigfoot motor. Was out on the lake night of July 4th watching various fireworks, and put the throttle in idle to to sit and watch. Had music playing (not thru boat system) so didn't notice that motor had stopped maybe 5-10 minutes prior. When I tried to leave and notice the motor wasn't running, tried to start and it would not turn over at all. Nav lights were still on. I turned them off and retried to start but nothing. The battery (EverStart 24MS Marine) is only 4 months old and has not given any previous indication of weakening. The only electrical equipment on the boat that uses battery power are the 3 Nav lights.I only use the boat 2-3 times a month and for about an hour at a time. I took the battery out yesterday, have had it on a 2 amp slow charge for about 20 hours. The voltage now reads 13.9 and the % charge is 74. Do I have a charging problem with the motor or a battery problem? Thanks

 

[Chris1956]

It sounds like a charging problem, however, it is not definitive.

Disconnect the battery from the charger and let her sit, unconnected overnight. Now, measure the voltage of the battery at the terminals. The voltage should obviously be good, say 12V at a minimum.

Now connect to the motor and measure the voltage after a few minutes.

Note that voltage, and start motor on flusher. Set motor to fast idle and measure voltage at battery terminals. It should be higher than before starting, if motor is charging.

If motor is charging, and battery still runs down, you have either a bad battery or a parasitic load on the battery. You will need to use an ammeter to see if current is being used by the motor when it is not running.

 

[cheeksf16]

Thanks Chris. I did disconnect the battery, but it was pretty much dead (10.7 v). As I said earlier, I put it on a slow charge. It took about 24 hours to get 100% charge and 15.1 v. Since I don't use the boat often and there are only 3 Nav lights running on the battery, I'm wondering if the battery is not charging and is able to hold enough charge to sustain several outings before going dead. I will put the battery back in the boat and check the voltage before starting, then start and go out for a short, close spin then check the voltage again after. Fortunately, I live on the lake so my boat is in the water all the time. I also am considering getting a car jump starter to keep in the boat. I'm pretty good at fixing things, but I really don't know much about boats/motors. I'm not even sure what this motor uses to charge the battery. I can certainly remove and replace parts, but not good at troubleshooting outboard motors. Thanks for your help/advice.

 

[Chris1956]

Look up your motor by year and HP at crowleymarine web site and see what kind of battery charging it has.

All outboard battery charging is initiated by the stator, and then goes to a voltage regulator or rectifier or some combo of both. Normally, the stators are good, and the VRs or rectifiers are the weakpoint.

VRs and rectifiers are usually available aftermarket on the web, so you can look around for a good price.

 

[gm280]

I have no idea about your battery, but a mere 2 amp charger really isn't enough. Yes it will charge eventually, but a larger charger current rate would be a much better option. JMHO

 

[cheeksf16]

OK, it's been over a month now and sadly to say, only more bad news. After charging my battery, I used the boat 4-5 times on short (< 1 hour) checking the battery charge before, during, and after each ride plus in between. My general conclusion was that the regulator was not charging the battery (voltage reduced very slightly each time checked; ie. one day 12.6, next day after using, 12.4) and never increased. It appeared that my short rides only using the battery to start the motor, was slowly using up the charge. Talking to a couple other boat owners, went on a hunch that the problem may be the rectifier, so ordered one and installed it yesterday. After installing the motor started up OK so I was happy that even if I didn't know that it solved the problem, at least I didn't make it worse ... or so I thought. I checked the voltage at a fast idle and it still didn't appear to be charging so I took the boat out for a spin to then check the voltage again. The engine ran very rough and I couldn't get more than 3500 RPM. I wasn't sure what was going on so i went back in, checked everything on the engine to make sure I hadn't disrupted anything and even changed the fuel filter even though it didn't seem dirty; the roughness seemed like a fuel issue. I took the boat out again with the same rough running results and the motor quit on me requiring me to swim/push it back to my dock. Once there, i tried to start the engine several times and although it would turn over and start, it would immediately die. Now I'm really confused. I guess the rectifier wasn't the not-charging problem, but I can't figure out what the relationship is with the rough engine running/quit.

 

[Chris1956]

The Electronic Fuel Injection (EFI) on your motor will use some power. With a low battery, maybe that is your rough running issue.

I would expect you to have a full voltage regulator on that motor, vs a rectifier. If you provide the year, I can look up the VR you need.

 

[cheeksf16]

The motor is listed as a 2006 Mercury Big Foot 60 hp EFI; Model # 1A60452HZ, Serial # 1C035033. The rectifier part number I put on was 893640T01. I took my 4 month old battery back to Walmart but because of COVID, they didn't have anyone to test it so they gave me a new one. I am going to put it in and take it for a (short) spin and see if that may have been the problem. I'm hoping the low voltage to the EFI was the problem with rough/quit running.
Thanks for your help.

 

[Chris1956]

OK, that is the correct voltage regulator for your motor. So if she won't charge, suspect the stator, as that is the other component of the charging system, outside the wiring.

the wiring is good, right?

 

[cheeksf16]

Yes, and I'm a bit more hopeful now after solving most of the seemingly unrelated, but coincidental problems (some of which I caused). Yesterday I tried to start the motor after connecting the new battery. It would turn over fine but not start – seemed like it wasn’t getting gas. I looked thoroughly over the engine to see if there was anything I could find that would cause the problems (BTW, I’m working on my motor with the boat in the water). First, the fuel filter bowl was cross-threaded, not sealed completely. Second, one of the spark plug wires (closest to the rectifier I replaced) was backed off the spark plug enough not to make a connection. I corrected both of these mistakes but the engine would still not start. It seemed like the motor just needed more gas during the start attempt so I pushed the override button to keep the throttle in neutral, turned the key and advanced the throttle and sure enough it started and stayed running once placed in idle. By that time it was getting dark, I was tired, and I declared a weak victory. Today I went back out, hooked up the battery, turned the key and the engine fired up immediately, continued to run at idle. My wife and I both wore swimming suits to take it out for a spin just in case we had to swim push it back in. The 'test run' was a series of short runs back and forth very close to the dock until we finally were confident enough to venture further out and wound up slow cruising up and down our own finger of the lake - no problems and engine ran very smoothly. Additionally, I checked the battery voltage before we started: 12.40v. After our slow cruise at about 2500 RPM for 30 or so minutes, 12.52v; so although not a lot, significant in the fact that it was charging ... I don't know if the problem was the rectifier or the battery as my test after changing the rectifier was aborted because of the other problems.
I know that many of my problems are self induced and would probably never happen to you, Chris, with your experience but wanted to 'come clean' with my screw-ups for any other inexperienced mariners that may be able to avoid the same mistakes. In that same vein, I appreciate your help and patience with me - kept me going with the trouble-shooting.

 

[Chris1956]

Glad it worked out for you. Screw ups happen to everyone. The best you can hope for is not the screw up the same item more than once, and to have less screw ups as time goes on.

If the battery is charging at all, it is likely fine, as the voltage regulators tend to be a good/no good item.

 

[cheeksf16]

Hoping that the issue is resolved, at least for now; after all, it is a boat ...

Thanks again