Another portable battery charger

[Cornelius]

Just finished putting together a portable battery charger, using a B&S 5HP engine, and a Bosch 12V, 70A alternator. 





Now, the frame are made of pine so i don't expect it to hold together forever, but so far it's holding up pretty good.

I removed the internal regulator from the brush-holder, and mounted it on the 'control-panel with a switch that allows me to use either the regulator or the rheostat. With the rheostat, i have the ability to go easy on the motor with a larger, deeply discharged battery; run a manual equalizing, or just manually control the charge. The regulator are ok to use to just let it do its job; just bring the charge up.

I can see the need to separate the control panel entirely from the generator frame, since the instruments are the cheapest you can get... ( the ammeter needle are vibrating +/- 30A )

[veggie]

Looking good !
I like the rheostat idea. Something I neglected in my alternator setup.
I also noticed the rubber engine mounts. Does she move around very much ?

veggie

[Cornelius]

Actually, yes... (Though, i've only tested it on snow-covered ground... )
The rubber mounts reduce the hard vibration transfer to the ground/floor, but the rubber are a bit on the hard side to prevent 'walking'... I've noticed that commercial generators have much softer rubber mounts than the weight of the engine should dictate, but those i've used is what i'd had laying around...

FYI:
The alternator are negative regulated, so it's easy to add the switch between regulator and rheostat; i switch the ground between the regulator and rheostat. The regulator regulates the current on the negative side on the rotor; with the switch, i lift negative from the regulator and in that, makes it inert, and then control the current via the negative to the rotor with the rheostat.

[rcavictim]

That is how early man made electrical generators before metals were invented. 

[mbryner]

Looks nice!   One concern:  it looks like the engine rubber vibration dampeners are separate from the alternator mount.   That would give you varying belt tension, and chirping and slipping.   Don't you want the engine and alternator to move together?

[vdubnut62]

Put a big 'ol sprang on it for belt tension an let it rock!
Looks like it's for proof of concept anyway.
Nice setup Cornelius, I like the rheostat, that is a really good idea!
I have a guy here that sells Hardly Freight 6.5 hp engines for $100, I really need to get one and use the big Delco off the bus to build my own. I just need to "borrow" a few more ideas from the membership here.
Ron.

[Cornelius]

Yes, the alternator mount are a concern, but Ron's idea with a spring are good. The engine are rather light; only 17kg, so with the rather stiff rubber feet i use, the engine doesn't move much, and the belt seems to behave so far.

I have never got around to learn to weld properly, and i like to work with wood... The frame was something i had used for another project, so yes, it's a prototype. Though, my prototypes tends to get permanent if they work as is...

Edit:
If i get my hands on an alternator that goes ccw, i could make the whole unit much more compact... Though, the direction of the alternator just depends on the cooling fan, doesn't it?

[jasoncarter]

How's this for compact?

[vdubnut62]

Well ain't that slick, and cute too!  where did you find that 'lil feller?
From what I gather Cornelius, an alternator doesn't care which way it spins, just a matter of the fan. If you were close enough,
I could hook you up with just about any kind of wood you wanted for a mount. I have an old Woodmizer LT40 band mill.
Ron

[veggie]

How's this for compact?

Jason,

Where did you find that 12 vdc generator picture ?

veggie

[jasoncarter]

I built it.  About 6 years ago I built a CNC plasma table.  This was one of the "gee I wonder what all I can do with this thing" projects.  Initially I started out making a mount for a Zena welder that I had picked up reasonably cheap.  I built mount for a horizontal shaft engine  that held a zena welder and delco 10si alternator.  The old 8hp engine I put the setup on wasn't quite up to the task so then I made a mount for a vertical shaft 15hp riding lawnmower engine.  The vertical shaft mount was kind of neat.  It was made with interlocking slots and tabs.  I dug up some of the old pictures in case some of you guys were interested.  I don't have any pictures of the vertical shaft mount with the engine in place but maybe you can see how it worked.  Any way, the simple battery charger was the last of my different ways to connect an alternator to a small engine.

[Henry W]

Very nice setup indeed.

If you like to share on how to build one I think you will get some interest here.

I believe it will mount to lots of air cooled gas engines

Henry

[Lloyd]

jasoncarter

What's your take on the Zena alts,,,any reports on quality of machine???

Lloyd

[Cornelius]

I really like that red mount bracket Jason!
With the hole for the alternator on the other side, i could mount the alternator underneath the muffler (look at my 3rd pic.), making it almost dissapear into the gen.
The motor has 4 threaded holes around the axle, so i agree with Henry.

Lots of good ideas are popping up here; thanks guys!

[Henry W]

I really like that red mount bracket Jason!
With the hole for the alternator on the other side, i could mount the alternator underneath the muffler (look at my 3rd pic.), making it almost dissapear into the gen.
The motor has 4 threaded holes around the axle, so i agree with Henry.

Lots of good ideas are popping up here; thanks guys!

You two should work together and see if you can get something going.

That would be a great portable setup.

Henry