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"MacGuyverized" Batterey tender

xjintx

NAXJA Forum User
Location
Eddy, TX
Hey I saw a post on LSJC and was wondering ;)

Some guy had a pic he did not do it... on a trailer for towing vehicles there was an alternator mounted to charge the battery for the winch.

The neat thing (I thought) was the alternator had a fan attached... therefore while driving...wind turns fan turning alternator and keeps a charge on the battery.

I want to add a bigger winch to my trailer and onboard battery. What do you think about this idea? Think wind would be enough?

I like the "thinking out of the box" concept.
 
My tow vehicle is setup to charge battery as I tow my 5th wheel however my son and others borrow the trailer and most times theirs is not. heck some borrow it and don't have brake controllers either.

Just thinking I like this alternative!
 
Unless you add something to drive the field coil in the alternator and it'll produce meaningful output at a few hundred RPM, it likely won't work too well.

I'd go with a solar charger or trickle charge off the light harness.
 
see this is the input I was looking for?

I'm an electrical novice... what is meant by adding to the Field Coil???
 
alternators don't have a permanently magnetized rotor, they have a coil on it that provides the magnetic field for the stator coils. So you need a circuit that watches the battery charge voltage and modulates the float voltage till the charge voltage is in the proper range.

Some alternators have a built in regulator, or you can buy an external standalone one. The ones with a built in regulator will have only a single terminal, the B+ terminal, instead of having a B+ terminal and a smaller wiring harness with a few studs or a couple wires going to it.
 
alternators don't have a permanently magnetized rotor, they have a coil on it that provides the magnetic field for the stator coils. So you need a circuit that watches the battery charge voltage and modulates the float voltage till the charge voltage is in the proper range.

Some alternators have a built in regulator, or you can buy an external standalone one. The ones with a built in regulator will have only a single terminal, the B+ terminal, instead of having a B+ terminal and a smaller wiring harness with a few studs or a couple wires going to it.

SPOBI! They make self exciting alternators foo and si alternator makes good output below normal engine idle speeds
 
SPOBI! They make self exciting alternators foo and si alternator makes good output below normal engine idle speeds
I do believe I covered that in the post you quoted :rolleyes:

Are you like this to your friends or just everyone you feel like annoying?
 
Hey guys i was just looking at any suggestions....

ANY recommendations are appreciated.

So is there a source for these alternat alternators ;)

I think I want to try this :)
 
I believe some GM and Toyota vehicles had internally regulated single-post alternators. Last time I needed one (to build a DC generator out of an old 2-stroke motor) I just wandered around my local pull-n-pay junkyard looking at alternators till I saw one that had no field coil wiring connections.
 
Have you ever tried to turn an alternator with a load on it? I had one connected to a 5hp Briggs and a fully dischaged battery would stall it at full throttle. Think about how big a windmill blade you'll need to make 5hp..

On the other hand, sailboats use small windmills to charge the batteries, so there might be something to this.
 
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