kicker w/charging system

[kingsfisherman]

Well got my 18hp Nissan mounted on the transom of my boat but need to know how to hook up the battery cables. I am thinking of hooking it up diectly to the starting battery that way its being charged while I'm trolling. just wondered if it should be connected through the isolator or not?

 

[tashasdaddy]

Re: kicker w/charging system

most bigger outboards with charging sytems are connected directly to the battery. the isolator is for multiple battery systems.

 

[Silvertip]

Re: kicker w/charging system

Battery cables go directly to the battery. Its the charging output lead that goes to an isolator if you have one. The starting battery gets charged through the battery cables.

 

[Silvertip]

Re: kicker w/charging system

Just read this again and noticed that you said this was a kicker. Are you intending to use the big engine start battery to start the Nissan as well? If so, the high output alternator on the big engine may back feed the electrical system on the Nissan and damage the rectifier/regulator.

 

[Texasmark]

Re: kicker w/charging system

I agree with Silvertip. Backfeed could be a problem if your rectifier diodes are low reverse voltage, which they usually are (50v as I recall). And if you back feed and blow a (just one is all it takes) diode, you will drain your batteries and may kill your big engines charger by over/continuous current loading it. Half the rectifiers in your charger are tied directly to ground. If you overvoltage one and it shorts, you have a dead short to ground on your 12v power line.

Your 18 probably puts out 5 amps at WOT and your big engine 3 or 4 times that. Seems that connecting the alternator to the starting battery may not be in your best interest.

Mark

 

[phatmanmike]

Re: kicker w/charging system

could you hook up a switch, the dual battery switch kind, but instead of dual batteries, you wire it for dual motors, so you can switch between charging systems. switch to the large motor as #1 and the smaller motor as #2.