[AT] Batteries charged backwards.

[Thomas Martin]

Surely US battery chargers have adjustable amperage?

I thought it was a given that you wouldn't put 50 amps into a dead battery...

Tom

> On 13 February 2020 at 03:14 Stephen Offiler <soffiler at gmail.com> wrote:
> 
>     Hold on.  A completely dead 12V battery connected to a good 12V battery is going to cause very large current to flow into the dead one. This is not a good idea.
> 
>     SO
> 
> 
>     On Wed, Feb 12, 2020 at 9:08 AM < szabelski at wildblue.net mailto:szabelski at wildblue.net > wrote:
> 
>         > > Cecil,
> > 
> >         I agree with completely discharging the batteries and then putting the batteries in parallel one at a time with a good 12V battery. The batteries will try to equalize when in parallel.  When you drain the battery, take the load off and let the battery sit for a while, then put the load back on and drain some more.
> > 
> >         You should use a battery charger that has a trickle charge feature. This puts a full charge into the battery at first, then drops down to a small charge to top the battery off. You may have to do this several times and should leave the charger on for at least one full day. Don’t rush the job.
> > 
> >         You can also check that each cell is good by taking a reading between each cell. A bad cell will indicate a lower charge then the others. Do this with every recharge attempt and note if you’re making any progress.
> > 
> >         Don’t know if you’ve ever gone on-line to look for videos on bringing dead batteries back to life, but their are some that show how to drain a battery, rinse it out, then refill and recharge. They appear to work out quite well, but I can’t swear by them since I’ve never done anything like this myself.
> > 
> >         Good luck!
> > 
> >         Carl
> >         ----- Original Message -----
> >         From: Thomas Martin < tmartin at xtra.co.nz mailto:tmartin at xtra.co.nz >
> >         To: Antique Tractor Email Discussion Group < at at lists.antique-tractor.com mailto:at at lists.antique-tractor.com >
> >         Sent: Wed, 12 Feb 2020 00:24:36 -0500 (EST)
> >         Subject: Re: [AT] Batteries charged backwards.
> > 
> >         Hi Cecil
> >         I  consulted a very good friend on the other-side of the isle.
> >         Tony is auto-electrician, of vast car, truck & tractor experience.
> >         He says you MUST discharge the batteries, separately with a bulb.
> >         They need to completely discharged. No measurable voltage.
> >         Then one battery at a time needs to be placed in parallel with another
> >         fully charged 12v battery, they then need to be connected to a 12v
> >         charger...
> > 
> >         Tom
> > 
> >         > On 12 February 2020 at 15:31 Cecil Bearden < crbearden at copper.net mailto:crbearden at copper.net > wrote:
> >         >
> >         >
> >         >
> >         > > I had 2 group 31 batteries out of the tractor that were completely
> >         > > dead.  I hooked them up in series and connected my 24Vcharger to them
> >         > > as It was handy and I wanted to charge both.  After a couple of days I
> >         > > checked them and found that I had hooked the charger backwards.  I
> >         > > hooked a couple of incandescent headlights to drain the battery, but
> >         > > after 3 days they won't light up the headlights, but they still have a
> >         > > lot of spark when shorted with cables..  A guy at my battery shop said
> >         > > I should hook up a 6volt light to them and use that to run them
> >         > > down....  At $100/ea, I need to try to save these...
> >         > > Cecil
> >         > _______________________________________________
> >         > AT mailing list
> >         > AT at lists.antique-tractor.com mailto:AT at lists.antique-tractor.com
> >         > http://lists.antique-tractor.com/listinfo.cgi/at-antique-tractor.com
> >         _______________________________________________
> >         AT mailing list
> >         AT at lists.antique-tractor.com mailto:AT at lists.antique-tractor.com
> >         http://lists.antique-tractor.com/listinfo.cgi/at-antique-tractor.com
> > 
> >         _______________________________________________
> >         AT mailing list
> >         AT at lists.antique-tractor.com mailto:AT at lists.antique-tractor.com
> >         http://lists.antique-tractor.com/listinfo.cgi/at-antique-tractor.com
> > 
> >     >     _______________________________________________
>     AT mailing list
>     AT at lists.antique-tractor.com
>     http://lists.antique-tractor.com/listinfo.cgi/at-antique-tractor.com
> 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.antique-tractor.com/pipermail/at-antique-tractor.com/attachments/20200213/96e8c21f/attachment.htm>