Lead-Acid battery reverse polarity charge

[arrie]

Ahh....
nothing like a good bit of humour.

By the way, how do you reverse polarity charge a SLA battery without it blowing up?
that was the one thing about this post I never got.

 

[Nigel Goodwin]

Ahh....
nothing like a good bit of humour.

By the way, how do you reverse polarity charge a SLA battery without it blowing up?
that was the one thing about this post I never got.

With your fingers and toes crossed!

But to be more serious, I would suggest you have to completely flatten the battery, and then only reverse charge it gently.

 

[arrie]

the point I was trying to make is, you need to be really good at what you're doing to do so without harm, so what is the chances of it happening.

Besides, should SLA batts. drain sufficiently, you chuck'em away, no questions asked.
So how would someone purposefully drain it to such a state that it can be reverse charged. I don't understand.
SLA is normally only trickle charged in any case to prolong lifespan.

 

[ericgibbs]

the point I was trying to make is, you need to be really good at what you're doing to do so without harm, so what is the chances of it happening.

Besides, should SLA batts. drain sufficiently, you chuck'em away, no questions asked.
So how would someone purposefully drain it to such a state that it can be reverse charged. I don't understand.
SLA is normally only trickle charged in any case to prolong lifespan.

hi arrie
I thought the OP said it was a car battery, 'wet lead acid' not a SLA.

 

[arrie]

oops, you're right.

thanks for jolting my memory, had 2 hours sleep last night, mmmmm.....
that might be the cause.
Then again, it can be the alzheimers light.

 

[john1]

"Alzheimers Light" ... ?

Is that one of these new alco-pops i keep hearing about ?

 

[jpanhalt]

"Alzheimers Light" ... ?

Is that one of these new alco-pops i keep hearing about ?

It sure ain't Budweiser.

John

 

[arrie]

Sorry my spelling there should have given the whole thing away.
When you get old sometimes, you cannot remember things and basically become senile, an illness called Alzheimer's disease.
Well now, if you're a bit younger, and cannot remember things from time to time, we jokingly say that you have alzheimers light.
Probably only a South African thing.

The intention is not to make fun of the real disease as it's very serious, but forgetfulness can be bloody irritating.

 

[3v0]

Had to dig back a few posts...

I wonder who would try to charge a battery the wrong way in the first place..

As I recall it: We had a combine (grain harvester) with a generator (dynamo to Nigel) that had gone bad. The generator was replaced. As part of the process you need to hook the generator to a battery to polarize it. If you polarize it backward the + and - connections become reversed. The battery was dead when the generator was replace, the backward polarized generator charged it backward. The battery charged but not enough to work well. I think it went dead each night. Could have some of this wrong as it was 40 or so years ago.

 

[mneary]

My 65+ friends call temporary forgetfulness "a senior moment".

 

[arrie]

haha, a senior moment.

People might look at me funny when I use such terms though, I'm far from senior.
I think I'll mock my dad with that one in the future a bit, hehehe.

 

[zeka]

Here also !



Hello,

I couldn't believe it

Just checking the remaining voltage of a SLA battery... it was showing reversed polarity!
OMG - was it a mistake @ the manufacturing? Or just a reversed marking (mistake)?

Now I see from the posts here that it happens and it works

Question: should it be kept like that forever... or is it better to to put it back to normal (2nd life )?

Thanks for your comments

 

[Kaiser 54]

Bttery Reverse Polarity

The 12 volt battery in my 1960 Studebaker was drained over time due to the glove box light being on. When I tried to charge it, connecting the red charger wire to the positive post and the black charger wire to the negative post the charger inidicated "reverse polarity". I tried another charger without the reverse polarity protection and got a lot of sparks. After reversing the charger connections the battery charged in the reverse polarity mode. I am allowing the battery to discharge again and hope that the polarity will go back to the original. If it does not, is there any way of forcing the battery to change back to the correct polarities?

 

[tcmtech]

Sure, run it stone dead and then connect the charger the right way. Just make sure you repolarize the old generator so you don't fry the regulator when you start it up.