Charging a battery backwards

It's gotta be "dead, dead" before going back the other way.

Allan

I would start with a new battery-see if it works

NEVER TRY TO REVIVE A BATTERY IN THIS SITUATION
the plates could be messed up and the thing could explode

The problem in guessing your posts on this board is that there are folks here who do have experience and are not shy at pointing out your inexperience if you are being obnoxious about it. Your professional advice that the plates could be "messed up" have no technical basis.

By the same token, those with experience try not to embarrass those without experience because if someone makes fun of you for asking what they think is a stupid question, then you quit asking and may damage a tractor or get hurt.

The only stupid question is the one that is not asked, and the only one who mkes no mistakes is the one who does nothing. I am a registered professional mechanical engineer, I really farm with letter series Farmalls and I have hooked batteries up backwards (in a hurry, post on the opposite side from normal, and several M's with positive and negative ground). In fact I have made lots of mistakes farming and engineering but it is persistence that gets the job done, not perfection.

Anywho, the reaction of the lead n acid and lead sulpahte only yields one polarity as far as I know and regardless how his battery got discharged, EITHER from a load or a load caused by hooking it up backwards to a charger, I still believe he has a chance of reviving it by a correct polarity charge. Of course, once a battery is completely shot it can NOT be revived or recharged so if thats the case then it may NOT be possible to revive it BUTTTTT TTTTT TTTT I still see no problem with giving it a try cuz I dont see the chances of it "blowing up" any greater then the chances of any battery blowing up from charging cuz after all, even charging a good battery causes expolsive gases which a spark could ignite.

Any thoughts?????

John T

That is total bunk, Pard.

Allan

The reason the starter still turns the same direction regardless of polarity is that its NOT a permanent (always same North/South polarity) magnet field motor like small low torque motors but relies on a current induced electromagnetic field.

Most tractor starters are SERIES WOUND MOTORS instead of shunt wound like a tractors DC Generator. The current flows though the Field and Armature wired in series. To reverse its direction (typical DC reversible motor) you would have to reverse the direction of current flow in ONLY one of its windings but in that series starter motor if you swap polarity you DO NOT change the North/South magnetic polarity of the field in relation to the armature, i.e. she still turns the same direction.

Some higher torque DC motors may have Compound windings in which some windings are series but others shunt, but I think the typical tractor starter is SERIES WOUND.

John T

• Hobby farm

The starter is a DC motor, but it is shunt wound, meaning that instead of one set of windings and a set of permanent magnets, there are two sets of windings (one fixed, one rotating) connected in series. Because reversing the polarity reverses the polarity in both sets of windings, the motor turns the same way no matter what.

Drain 'er clean down flat broke so even your little light won't come on. Then, bring 'er back up the other way.

You might have to polorize the generator for it to charge right; have to wait and see how it acts when ya get 'er going again.

Allan

I wish I knew a tenth as much as some of you guys!!

Sure good to have you guys around

Gene

Allan