[chas48]

Plug in an AC adaptor into your truck lighter. Then run an extention cord to your on- board battery charger. Charge your boat as you drive down the road.....

[chas48]

Guess not.........

[reeves]

chas48,
I'm no electrical wizard on this, but . . . your on-board charger receives it's power from an AC source and converts it to DC in your batteries. Your truck charges DC, so by hooking the truck alternator to the on-board charger would not be compatible without the use of a converter of some sort. And thus ends my shallow electrical knowledge. You are thinking though and that is a good thing, keep it up, something will come together.

[MTfishingrods]

Actually chas, what you want to do would work. the only thing I wonder is would it be worth it? How long of a drive is it versus how long of a charge would you get? Also you need to make sure your charger is not drwing to many amps for the outlet. Otherwise you would be good to go.

[rhahn427]

George .... he said toplug in an AC adapter to the cigarette lighter which would convert the DC to AC then connected to the battery Charger which would convert back to DC. I think it would be simpler to simply connect a cigarette lighter plug to wires with battery clips and connect that to the battery thus going DC to DC.

[reeves]

Thanks rhahn427, now it makes sense and probably could work, I missed that very important part. Your idea has merit as well. Would it be worth checking the load on the alternator to make sure it can handle the extra demand? Just a thought.

[Spike-A-Pike]

Something that 4 wheelers do is add a second alternator if they plan to run extra lights, power tools, refrigerators, etc. I don't know if the extra drag of a second alternator on the drive line would be worth the extra fuel with prices always going up?

[MDC]

I'm no expert either, but it seems to me the power inverter would have to be the part to keep up instead of the alternator. Inverters are available in many sizes (output ratings) but I would wonder what the draw would be from the charger.
If you just hooked the wires from the lighter socket to the battery I don't think it would charge. The socket most likely doesn't put out enough amperage to charge the battery. If the battery is putting out more amperage than the socket, you might cause real damage to your truck.
There has to be an electrical guru here somewhere.

I'll also second MT's thought of how far you would have to drive to do any good.

[redg8r]

You might wanna check the manual that came with the charger and the manual that came with the converter.
Depending on the converter, you might actually damage your battery. I dont understand why but it has something to do with the sinewave produced by the converter.

I found out the hard way by hooking up my 18v tool battery charger to an AC converter to charge my batteries on the road.
It damaged my nicad batteries.

[Spike-A-Pike]

I still think a high amp alternator might be able to keep the tow vehicle's battery charged and have enough amps left to charge the boat batteries. I was thinking of a 10 gage wire run out to my tow hitch, a connector, another 10 gage wire to run the length of the trailer, and a couple of clamps to connect to one or both 12 volt batteries in the boat.

I'm no expert, so I put the question to National Auto Electric... I'll report what I get.