Battery Chargers

[BurksFallsMan]

The old charger a little improved-Now will be spare.

A new set up with the regulator intact inside (same type of alternator Delco-S12

with 5.5 HP

[alcas]

Looks good, congratulations.

Recently we were in the Amazon jungle, and we got stuck in mud, it was late and we could not see, so we slept and in the morning found ourselves without battery and could not start the jeep. Your charger seems a bit large to carry around. Assuming you had 4 guys willing to turn a lever or run a treadmill, what do you think, would be the easiest way to charge a battery by hand. If you could suggest a charger we could work on how to make it turn.

regards

[RogerAS]

Hi,

I had he same thing happen in the Trout Creek Wilderness of eastern Oregon. Would'a gave a lot to not have to walk out 30+ miles.

For a portable unit a DC permanent magnet motor and a crank handle would work, with a blocking diode. I'd crank for some time rather than walk 30 miles.

RogerAS

[charged]

build yourself a simple dynamo with an old bicycle. Make a bunch of windings to stick around the outside of the back wheel and line the wheel with magnets.

Wire all the windings in series with a single heavy diode on one lead. Feed the pulsed DC output to a large electrolytic capacitor that's strapped to the bike frame.

Make a simple commutator on the bike wheel that discharges the capacitor into your battery once per wheel rotation.

You could build all this onto a small bicycle and keep it strapped to the outside of your vehicle in case of emergencies.

[bob g]

i think this is where the small pv panel would really come in handy!

i think i could kick back and wait on the sun for quite a while before i walked 30 miles out of anywhere.

failing that i would have thought seriously about rigging up a pull rope to the alternator and yanked the hell out of it before i walked that far.

i wonder how many yanks it would take?

perhaps i sappling with a rope down over the puller so i could yank it up and down, causing the alternator to first go cw and then ccw.....

you get the idea... necessity is truely the mother of invention.

bob g

[ToddH]

I have a small Coleman generator that has a plug for charging 12VDC batteries and has a 120VAC receptacle. It's really compact, about a square foot in dimension and around 15 pounds or so in weight.

I sometimes carried it in my Jeep when camping in the desert. It's powered by a 2-stroke weed eater type engine.

Bought it for $70US at a swap meet.

[alcas]

Yours sound like the easy thing to do, please allow for my ignorance of things electrical and give me some examples of the type of permanet magnet motor you are talking about, and were do i place the diode?

[PaulJ]

   Looks like you're using a brake disc as a flywheel. If so, great idea - did you have any problems mounting or balancing it?

[BurksFallsMan]

Ypu are right ! Still not done with the balancing but I plan just to run a dial indicator on the perisphery and it should do it.

For the people looking for a "spare" when you get stuck: HARBOR FRIGHT has some battery packs portable (like the ones the auto shops use) ad are $60

Charge it at home an carry for many weeks. Good for 20 30 busters.

Wilson

[Radomike]

That's a solid-looking unit there.  I like the exhaust heat shield.

  Is the brake disk also the pulley, as well as the flywheel?  How did you center and mount it?

[dozer]

Looks good.  Brake-disc is a good idea.  A Briggs will shake itself to pieces in a few hours without some kind of additional flywheel.

Regarding the idea of winding a rope on the alt and yanking it to recharge a car battery...

...you'll be yanking it for a VERY long time <g>.

Actually, I doubt you could ever put any charge into the battery that way.

The alt. won't put out enough voltage until it gets over a certain RPM.  Notice the very small pulleys on alt's....they're wound to run at 5k-10k rpm to charge a 12v batt.  Hard to yank it that fast...

The avg. car-batt is about 40 amp-hours...even assuming you can start the jeep on a half-charge, that's still an awful lot of hand-cranking.  Could be done tho...with a hand-crank gen I mean; not yanking a rope on the car's own alt.

A human can only put out about a hundred watts of arm-power on any kind of ongoing basis.  And maybe 200 watts of leg-power.  Both of these assume you're in pretty good shape.  Better by far to use a leg-driven device; but since 150 watts is only 10 amps at 15v charge voltage, ya still gotta expect to crank for several hours.

The little Coleman's and Hondas that I've seen with the dual outputs will only put out about 10-15 amps on the 12v output.    Probably looking at 3+ hours continuous running to get enough charge in the batt for starting.

Best thing I ever made for this was a chainsaw-engine direct driving one of those newer alt's that are so small....I think it was a Shinden, 90 amp unit off a '95 ZJ.  Chainsaw engines like to run fast...as do alts...a good match.  Direct-drive eliminates the belt losses.

The whole assy. only weighs 15 lbs.  And this thing will put 60+ amps into the battery, rather than 10-15.  20 minutes will put enough charge in to crank it, and leaving the genny on while cranking will usually start a vehicle.  I carry it in the yard-truck in case one of the Cats gets a dead battery in some place where I can't get the truck to.

Have to admit...it's not the most pleasant-sounding device I've ever built... <g>...but it's easy to carry and gets the job done.