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Power a trailer with a generator connected to the axle? Answered

I just rewired the family's "camping trailer" and the next project that I have to tackle is power. Don't ask why we need a bunch of power when camping, it makes stuff more fun. Anyhow two of the ideas my dad and I have are theoretically easy. The first one is something that is really simple, just some solar cells. However my initial  thought is that it may not be enough to power the car/marine batteries on the trailer in a manageable amount of time (with a small budget). The second idea is to connect a generator head(s) to the axle of the trailer, so whenever we are driving the trailer (often for about an hour on the highway) the batteries are charging
My questions are, what type of generator heads (if that is what I want) should I use? What type of gearing would I need? Could this be worked on a humble budget? Would this be practical for charging car/marine batteries?
Thanks, Jake J


You have a perfectly fine alternator in your car - use a battery isolator and a proper sized cable with an Anderson plug to connect the trailer to the car.
This will charge your spare betteries the most efficient and safest way.
A generator on your axles is not only a bad idea but also illegal in most countries.
Solar depends on much power you need and what size panels you use, on a budget you will never get enough power this way.
For really big demand during camping someone invented a thing called petrol generator if I am not mistaken.
Modern versions come with 12V and 240V (110 for the US) output and work as inverters, so quite efficient and quite.

Years ago someone told me, that putting such an alternator on each wheel of his car and charging a back seat of batteries let him add a large dc motor slip clutched to the drive shaft, which reduced fuel cost by 90% ;-)

Yes, the guy moved on and drives his car now on water with a fuel cell operated by the waste heat of the exhaust ;)

Start by defining how much charge you need. Pulling it off the vehicle alternator is probably the most efficient method.

I don't believe your axles will be spinning. I may be wrong but usually its the hubs or drums that spin on the spindles. You would have to have whatever generator spinning on the inside sidewall of the tire.

Lots of people have solar panels on their trailers. Just depends how cheap you could get panels and a charge controller.

I've seen ideas on home made wind mills here on instructables. Maybe that would work for you while you are driving??

That's about what I have for some general knowledge, but maybe it helped you out a bit