Battery Charger Experts?

[Zeke Boniface]

My dad owned a couple 6 amp Schauer battery chargers in the 60's and 70's. When a battery wasn't badly discharged, those chargers would begin charging at four amps or so. When the battery was seriously discharged, the ammeter would peg for a few seconds, the charger would shut itself off for a bit, then the cycle would repeat. It took some doing to get a really dead battery to charge.

Today I have several vintage chargers of the same type, and none of them will put more than a couple amps into a battery regardless of charge. I have a ten year old Schumacker that isn't much better. (I didn't have a Fluke clamp meter back in the day, but now it isn't hard to confirm the battery's state of charge and the output of the charger.) The charger ammeter will never peg when connected to a battery, but will readily peg when the charger clamps are flashed together.

Any of my old chargers will fully charge a battery sooner or later.

As we speak, one of them is charging a half discharged battery at a blazing 1 amp.

I have a bunch of batteries in a bunch of tractors, trucks, and dozers, and 2 amps is about the most to expect from any charger on any battery.

Interestingly, my 8N with 12 volt alternator and ammeter seems to charge its battery normally; but none of the chargers will. Ideas?

Zeke B.

 

[pinball]

I think its been proven the lower the charging amps less likely to hurt the battery. that's why chargers that put out 10 amps or so should only be used in dire situations but not to long of a time. boosters seems to be especially bad for a weak battery. I rarely use mine anymore.

 

[Janicholson]

I own 2 chargers that are the size of 1/2 loaf of bread. Neither makes a real dent unless left on charge for 10 hours or so. Not much heavy copper in them. Bigger and more expensive works. Jim

 

[BarnyardEngineering]

Two possible reasons:

1. Bad connections.
2. Batteries aren't as discharged as you think they are.

 

[dhermesc]

Agreed - the lower the charging amps the more likely the battery will take the charge without suffering damage. If you have a completely dead battery (lights left on overnight) starting out with a 2 amp charge is the best way to go.

 

[MarkB_MI]

These are very primitive devices, with no real regulation other than the overload protector that shuts them down if they're connected to a completely dead battery or a dead short. The current ratings are very optimistic; 2 amps is about right.

Other than bad connections, about the only failure mode would be to have a single blown diode. With one good diode and the other open, you'll only get half as much current as you should.

 

[Russ from MN]

I would check the diode/rectifier, I replaced a rectifier with a diode in an old one I have, now it doesn't seem to taper down, so I put a timer in it, I only let it charge a couple of hours. Seems to work OK though.

 

[rustred]

with 2 amps you can expect that charger to stay on the battery for at least a day to get any results. would need at least a 10 amp charger to get any results in an hr. or two. I am contemplating getting a solar power charger and mount it on the tractor shed and just have about 40 ft of wire and move it from tractor to tractor to keep battery's charged up or topped off.

 

[brooktre]

I ve got a couple of those maintainer chargers. One is rated for 2 amps and the other 4 amps. I use them to top off my batteries in the winter about once a month. I ll put them on and check them the next day and if the light is green I ll move to the next batteries. They do a good job and aren t that expensive. I like them because they won t over charge your batteries.

 

[Zeke Boniface]

My old chargers all came from estate sales, and they all act about the same. Maybe the previous owners used them until one diode failed, then bought a new charger. But the old charger, although it couldn't be readily fixed, still sort of worked, so it was kept around as a spare. Until I bought it at the estate sale. I have a diode test setting on my meter, about time I used it.

Besides that, I agree with everything that everyone has said; possible bad connections, the advantage of low charging rates, the case for just buying a new charger or maintainer...all of it.

Thanks,

Zeke B.