Jumping my car and the jumper leads start smoking...

Post Tue Dec 18, 2012 4:35 pm

Left my car alone for a week after my battery died on me whilst driving it. Went to jump it so i can go to halfords and see if its my battery or alternator thats playing up.

Hooked it up to another car, gave the other car some revs for a few minutes then when i went to start the e30 it would not turn over and the jumper cable connection started to smoke (on the side connected to my battery)

I did manage to start the e30 but as soon as i disconnected the jumper cable the car cut out instantly. So i gave up for today.

Post Tue Dec 18, 2012 4:46 pm

Maybe it was that as they were pretty pathetic. I have some heavy duty ones but there at the other house.

them jumper cables are shite, what can they actually jump?? as my battery isnt exactly huge.

Post Tue Dec 18, 2012 5:00 pm

If its a 6 pot especially, it will need a chunky quality battery together with chunky quality cables. Throw whatever you've got in the bin. Sounds like diables been there before...

Post Tue Dec 18, 2012 5:28 pm

been there and done it with jump leads labeled as " HEAVY DUTY " for them to start melting with the first bit or load you throw at them.. I've now got a set of home made ones which was made by an HGV / Plant mechanic these have been used for jumping artic lorries and bulldozers extra.

If using cheap cables your best to leave them connected for a good while with the boost car running before you try to start the stranded car

Post Tue Dec 18, 2012 5:36 pm

A couple of things, as above the bigger the cables the better, there is no cables that are too big

The fact that your car stopped when being driven, and it cut out when you disconnected it from the car you were jumping it off, would suggest that it is your alternator that is goosed. And now probably your battery.

Post Tue Dec 18, 2012 5:46 pm

Did you check that there was water in the battery (if it's that type) ? I don't think it'll retain much of a charge if it's running dry.

It does sound like your alternator is not getting electricity to the battery though, even with goosed batteries, a car will run in my experience, it just won't start again once you've turned it off.

When the car is running you should be getting about 14v on the battery IIRC, if not, the alternator is not doing it's job properly.

Post Tue Dec 18, 2012 5:52 pm

Kangman, just a word of warning, be careful when connecting batteries, they have been known to go bang, so always turn your face away when connecting..

Post Tue Dec 18, 2012 5:58 pm

Gert_8 wrote:Kangman, just a word of warning, be careful when connecting batteries, they have been known to go bang, so always turn your face away when connecting..

Rodger that.

Post Tue Dec 18, 2012 6:05 pm

Also be careful where you charge batteries, I had one develop a 'gumboil' during a failed charging attempt and I reckon it was very close to detonation when I checked on it, which isn't a good look on people, in a garage or in an engine bay or boot.

Post Tue Dec 18, 2012 7:26 pm

Also be aware that batteries, especially faulty ones, generate hydrogen gas when being charged. As I've posted on here before, I once almost blew the windscreen out of a mini pick up after I detonated hydrogen that had collected with the spark that occurred when I disconnected a fast charger.

Post Tue Dec 18, 2012 7:44 pm

Costco do some decent booster cables very cheap if you can find someone with membership....

I have the 20ft 4 guage ones here:

http://www.juice-automotive.com/booster ... ables.html

http://www.juice-automotive.com/booster ... power.html

Think they were about £23 with the VAT and they live in the dailly hack permanantly.

I also have a Clark JS1000 Boost pack at home for my very own "home start" service lol

Post Tue Dec 18, 2012 9:43 pm

Seemed to be a sort of slow motion explosion that just produced a dull red glow. Don't remember feeling any heat at all, just a blast of air and the unlatched doors blowing wide open.
This is the reason that rear mounted E30 batteries, and all other BMWs with internal batteries, have a small tube connected to the battery that vents to outside.

Post Thu Dec 20, 2012 6:36 pm

oh, and don't touch the ends to the leads together without disconnecting the positive from the charging car first . . . . . The ones we have at work are bound together so you can't deal with one cable at a time . . . . Can't see it, can't smell it, don't think about it and then BOOM!

I do it every time. And I'm an electrical engineer . . . . go figure.

Post Thu Dec 20, 2012 6:52 pm

If I'm charging, then I've generally got the battery removed anyway, and in that case it's vented, cooled and in a safe area whilst it charges. If the battery is still in the car, then all your doing is jumping and letting the alternator do the charging.

I'd very rarely charge with the battery in the car.

Post Fri Dec 21, 2012 12:32 pm

Brianmoooore wrote:Also be aware that batteries, especially faulty ones, generate hydrogen gas when being charged. As I've posted on here before, I once almost blew the windscreen out of a mini pick up after I detonated hydrogen that had collected with the spark that occurred when I disconnected a fast charger.

That's a new one. Jeez. Lucky I'm not dead at this rate.