Battery!!

Abi

Registered User
I had a flat battery so took it out to charge,
Don’t ask me how or why but I managed to connect the +- of the battery charger (not plugged in may I add), the wrong way round for a split second, saw a spark. Now the battery/charger are charging reversed polarity! Can this be reversed or are the battery/charger now scrap? Next time I’ll put my glasses on first!!


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Abi

Registered User
Needless to say not put it back I’m the vehicle till I can get an answer..


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traindweller

Registered User
Just a hope, but might be worth discharging the battery, with a load across the terminals and then recharging correctly. As it was only a flash you might get away with it.
Worth a try and no worse off than you are now.
 

merdzo

Registered User
U will damage the charger definitely... Check the charge fuse as first if u have it and if its burned out just replease it... Battery should be fine in any situation...
 

nluk100

Registered User
Unplug the charger - check for a reset button - replace fuse if required. Battery will be fine if it only sparked for a second and you removed it, or did you leave it to charge afterwards?
 

Abi

Registered User
Unplug the charger - check for a reset button - replace fuse if required. Battery will be fine if it only sparked for a second and you removed it, or did you leave it to charge afterwards?

I connected the charger the correct way and charged it. There’s no reset button either. The battery is now showing -12.66v


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nluk100

Registered User
You may need to discharge your battery (a battery specialist can do this for you) and then recharge it using another charger unless you can figure out why your charger is reverse charging. All I can think of is that's intelligent enough to realise that you connected the terminals the wrong way around but then you didn't unplug it before connecting the right way around and it continued to charge assuming you had the terminals the wrong way around still?? If that makes sense?
 
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merdzo

Registered User
Battery will give you again 12v power but if its damaged amperage will be too low. That's the main problem with the battery's.
 

traindweller

Registered User
I connected the charger the correct way and charged it. There’s no reset button either. The battery is now showing -12.66v


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So the battery is now charged then, why not wait to see if all is ok before buying a new one.
 

SootySport

Registered User
Charger may work in reverse, should say in instructions. Mine has a reset if its connected the wrong way round. When battery is fully charged should read about 14.4V , if its only 12.2V its toast.
 

Abi

Registered User
It’s on charge now, I will wait for a green light then check the voltage again.


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paddy

Registered User
You sure sooty, it might charge at 14-15 volt but 12.5v is quite good off charge. The battery has 6x 2v cells. if a cell was down it would be nearer 10v off charge.
Real test is voltage under load though. ie: put a meter on it and turn the starter.
 

paddy

Registered User
back in the day all cars were positive earth so you connected the live to the chassis , as cars moved from dynamo's to alternators we used to change the polarity of the car to negative earth by swapping the battery leads over and holding down the trip on the voltage regulator. I did this to my MGB in 1979
So its possible the battery charger just re polarised itself.....God i feel old :)
 

Abi

Registered User
back in the day all cars were positive earth so you connected the live to the chassis , as cars moved from dynamo's to alternators we used to change the polarity of the car to negative earth by swapping the battery leads over and holding down the trip on the voltage regulator. I did this to my MGB in 1979
So its possible the battery charger just re polarised itself.....God i feel old :)

Yep me too, converted my old car too!!


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SootySport

Registered User
back in the day all cars were positive earth so you connected the live to the chassis , as cars moved from dynamo's to alternators we used to change the polarity of the car to negative earth by swapping the battery leads over and holding down the trip on the voltage regulator. I did this to my MGB in 1979
So its possible the battery charger just re polarised itself.....God i feel old :)
So you’re nearly as old as me :hi:
 

paddy

Registered User
We are not old sooty just more experienced , i have another 5 years before i get my bus pass. hopefully the s3 will last till then :)
 

SootySport

Registered User
You're well behind me then, 68 next Thursday and I'm still in mid life crisis :rockwoot:
 

paddy

Registered User
My brothers 70 and he just bought a TT :) Age is just a number
 
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