pjbharrison 1:07pm, 7 April 2012
Need some advice on fitting a charging coil to outboard.

I was given a charging coil for my Yamaha 6Hp 2 stroke outboard. I'm told it will provide 6Amps.

Do I connect it straight to the battery? I believe it should connect through a voltage regulator or some such device to prevent over charging.

Can anyone advise me on what I need and perhaps a wiring diagram?

Hoping to cruise a bit further this season so want to ensure I have enough battery power for instruments, laptop and maybe tiller pilot.
Skykomish E29 7 years ago
errrr That must be some charging coil ours only produced less than 1 amp on the old 6 hp Mercury, and I believe even the modern ones only just manage an Amp. We were advised not to bother fitting one when we bought the new Mercury as the cost far outweighed the benefits.
I have to say up until then we were of the belief that we were merrily charging the battery from the outboard but in actual fact were only providing a trickle charge.

To be honest we only used a solar panel in the end to keep the battery charged throughout the summer and never found that we needed more except when we made our trip across the Thames and were living on the boat for 11 days, we then used the Marina power to give the battery a boost overnight with a conventional "intelligent" charger. Converting the Nav lights to LEDs made a significant difference.

Now we have an inboard engine with a nice 40 amp alternator those charging worries are a thing of the past .. I hope..lol
pjbharrison 7 years ago
Hi Malcolm
I was given the charging coil by an outboard specialists in return for some computers bits so it cost me nothing. I have a small solar charger that has done fine in keeping the battery topped up in the past. Just thought I'd fit it as I'm hoping to make some longer passages and want to install a tiller pilot.
Skykomish E29 Posted 7 years ago. Edited by Skykomish E29 (member) 7 years ago
I understand that providing you have all of the parts and they fit it is a really straight forward job. As our old engine was going to be scrapped we planned to have the charging coil taken off that and put onto the new engine as they were the same (Well that was the theory), it turned out that the later engine had a different flywheel and so the older system was not compatible, we would need to buy a newer system (which did actually produce a higher output (1 amp)) according to the Mercury dealer and the part alone was quite expensive.
I would think that even if your coil produces 6 amps there is not a great deal of chance that you will overcharge the normal deep cycle leisure battery considering they are around 70 amps (you would need to be running the engine for 5 hours continuously with no battery usage to even get it half charged.)However I would think your local Maplins would be able to help with a voltage regulator. I know thanks to Neil I fitted one to the solar panel for very reasonable price just as a precaution as it is continually charging the battery and this was very easy to fit with simple instructions.
Our old boat had a lead that we had to connect to the engine each time we installed it which I understand went directly to the battery had a foolproof connector
busy home [deleted] Posted 7 years ago. Edited by busy home (member) 7 years ago
Approx 2/3 amps from merc. charger.
Considering it takes a trickle charger all night to top up at 4 amps, you need not bother,,
Get a good 60 amp hr battery and a 20 w solar panel which charges all the time. no reg req, .
pjbharrison 7 years ago
Thanks for all the advice, Malcolm and Ron.
I'll probably run a lead straight to the battery with a connector in the middle so it can be disconnected when the engine is out of the well.
Any photos of Carrie, Ron?
Any photos of the completed dinghy, Malcolm?
busy home [deleted] 7 years ago
Carrie still has seat covers (plastic) on .. Still not properly finished inside
not looking wonderfull yet. Give me a month and I will post pics when afloat..
Chille is in Falmouth marina for the year, (O to be rich,)Near to Zeathar
(O to have a wife who works there) Geof and Rod have met and are planning their first burn up.. I will be photographing their bows,,
rothwell_neil 7 years ago
I used the honda charging coil and worked well. Can't test them as only output anything when a load applied but regulated so can plug straight into a battery with nothing else to do and a useful top up and nice to know that for motoring the autohelm isn't actually pulling anything as more than covered by the charging circuit.
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