Flat battery

[cjwatson]

Does anyone have experience with jump-starting cars, and would anyone around Cambridge be willing to help me do so tonight or tomorrow morning? I have the full set of cables and stuff, although random googling suggests I ought to be looking for goggles too. I'll owe you a drink or three ...

Comments

[beckyc.livejournal.com]

I've had to have my car jump started a couple of times before now, and nothing terrible happened when we (total novices) followed the instructions in the manual. No ignition of fumes or exploding doom or anything!

Or, for a more useful answer, I can bring my car over this evening if you like?

[beckyc.livejournal.com]

Er, FSVO "this evening" that is! When are you going to be in?

[cjwatson]

I'll be in until whenever I need to go to karate (so, if on foot, probably 7:45 or so), and then afterwards.

Since pjc50 said to ring him 10 minutes from now, I'll try him first, but thanks for the offer, and I might well take you up on it :-)

[crazyscot.livejournal.com]

I have a mains-powered charger and socket set, we could do it this way if there's time? (I forget how long it takes to charge, will dig the charger out when I get home..)

[pjc50.livejournal.com]

I'm around this evening - ring me after 6?

[pjc50.livejournal.com]

.. that is, early evening.

[emperor]

I'm around this evening after pizza, if that helps..

[terryfish.livejournal.com]

Join negative terminals together, join positive terminals together. start the good car and get it idling nicely

Then rev the good car up while trying to start the flat car.

Once the flat car is going, disconnect first the +ve and then the -ve leads from the flat car.

Then ideally; close the bonnet of the flat car and take it out for a good long (at least an hour) drive

(oh yeah; and sort out the good car too :-)

[cjwatson]

Once the flat car is going, disconnect first the +ve and then the -ve leads from the flat car.

Hm. The instructions on the cables I have say:

Start the vehicle, and after some minutes remove the Booster Cables from the former flat battery, starting with the Negative clip from both batteries, followed by the Positive clips from both batteries.

I assume it's dangerous to get it wrong?

[terryfish.livejournal.com]

The leads are right.

I temporarily forgot that elastic trickery comes from the -ve terminal

Dangerous?

[(Anonymous)]

Dangerous? You great wimp, it's only a 12V battery :-)

If you connect them up in the wrong order then apparently it might bleed a load of charge off the working car into some kind of black hole and both batteries go flat or something. If you connect them in the right order then it doesn't do that. But it's dead easy; connect the batteries in the right order (your leads are right), then have someone sit in the working car with the engine on and rev it, and then you sit in your flat car and start it. Lots of accelerator. Once it's running on its own, disconnect the leads in the right order, leave yours running for a bit, and then off to wherever you're going; as terry says, you should really take it for a reasonable drive so that the alternator gets a chance to charge your battery up again.

sil

Re: Dangerous?

[sarabian.livejournal.com]

Certainly isn't dangerous :)

It's something I've done many times over the past few years after being too tight fisted to replace the battery and then :-
a) leaving lights on overnight
b) having children turning lights on and not noticing
c) having the wife leave the lights on for about an hour
d) failing to start the car in the required 30 seconds before the battery went flat.

I got a new battery after d.

[armb.livejournal.com]

If you remove both clips from the one battery at once, there is a danger you will let them touch each other, shorting the other battery. Taking one lead off at both ends first avoids that risk. I don't think order should matter, but remember that negative battery terminals will be connected to the car chassis (except in very rare cases, like old Beetles), so touching the body with a lead connected to positive at the other end can also cause a short.

[gerald_duck]

mdw and I are doing curry in Cambridge this evening. You seem to have several offers already, but I can pop by if needs be.

You know my number.

[mtbc100.livejournal.com]

Generally, I find it works to attach the red cable to the positive terminals, clamp the black to the chassis, start and run the engine a bit, rev it a bit to start the other, then detach cables in reverse order. And, really, wear gloves and have a powder fire extinguisher handy.