Dead Battery

getmore4less

Some alternator faults will drain(draw current nor just not create any) a battery after the battery has been recharged by alternative means.

[Deleted User]

This is digressing a bit off topic, but as it's funny:

A few years back a partner of my mums used to have the use of my garage, and one day came knocking at the door. He had run his battery flat trying to start the car, helped himself to my charger then run the battery flat again, bought a new battery and run that one flat too. Now he was wanting a jump start.

I fetched the car, connected the leads and he tried again. It still wasn't starting, so I walked around to see what he was doing, and it turned out that he was one of these who stamps his foot on the throttle and floods the engine.

I told him to put the choke back in, push the pedal slowly to the floor and wait for the flooding to clear. So he put the choke in, and his foot down, turned the key, and then.....stamp stamp stamp! So I told him again, and again he stamped his foot. And again, and again, and again. My battery was getting quite flat as well by now, but eventually I managed to get him to keep his foot still long enough, and the engine fired.....

Then stamp stamp stamp and it promptly spluttered to a halt again. This was also repeated several times before I virtually dragged him out of the car by the collars and did the job myself.

After I got the engine running I took the air filter off and showed him the kickdown nozzle squirting neat petrol into the venturi, but I doubt it sunk in.

Back on topic, at one time you used to be able to take your alternator in to Joe Lucas and they would test it for free and then sell you the bits to fix it. If you left the alternator on the car there was a 15 minute labour charge.

Uniscots97

I do appreciate all the advice (and no I'm not ignoring it). I did try to get the car going again today and nearly managed it (at least its not cutting out when you disconnect the cables now) but I've had to contend with my OH not listening to me and trying ( stopped him) to connect the negative first and then got in my car and he's left the heating and everything else running. So I couldn't get my car up the hill before I lost the charge it had. Alternator seems fine (yes I'vehad it checked).

Ebe_Scrooge

I'm not quite sure what you're saying here. You jump-started it, disconnected the jump leads, and it was running OK ? Then you say "I couldn't get my car up the hill before I lost the charge it had". I'm confused - are you saying it cut out as you were driving it ?

If so, there's 2 broad areas to consider. If the alternator is not putting out any current, this could explain it. Without the alternator providing a current, the electricity required to create the sparks in the cylinders comes from the battery, which will soon be drained. You say the alternator has been checked ? Could it be that it's generating current, but the current is not getting to the rest of the circuit - i.e. it's not putting charge into the battery and / or not putting out current to the HT circuit ? You'd probably need a mechanic or auto electrician to verify that.

But if the "charging circuit" as a whole is working correctly, then it must be some other fault - fuel starvation, timing, any number of things.

I know this probably doesn't help much, but I'm puzzled as to why it's cutting out. Once the engine is running, it should keep running, no matter what the state of the battery - it would run even without a battery. The battery is only needed for starting ( and powering alarms, radio codes, etc. etc. when the ignition is off, but that's irrelevant here ). Yes, if the battery was kaput it may not hold a charge, leading to problems next time you try to start the car, but that's a different issue to what you've described.

[Deleted User]

TrickyWicky wrote: »

It is a bad idea if you have a car with an immobiliser that disables the cig lighter socket.. why? because it won't take any charge and you won't even realise but will waste money buying it.

Most come with a second lead, with a pair of crocodile clips, to connect directly to the battery.

That's what the inline connector (a few inches from the solar panel) is for.

[Deleted User]

EdGasket wrote: »

Jump starting a modern car is not recommended. You can blow one or both cars up in the process (well the electronics that is).

Jump starting from another car's battery, is different to using a Jump Starter pack how :huh:

TrickyWicky

There is no difference. 12V is 12V whichever car it comes from.

There is a lot of paranoia around about jump starting cars. Moons ago I jump started a young lady who was stranded and while she was attempting to chat me up, I had disconnected the jump leads from her car and was holding them both in my hand. Like an idiot I managed to touch them both together and short the battery. Sparks flew everywhere, the car continued running quite happily and I threw the crocs on the floor and kicked them apart.

The car was fine. Granted the green health indicator on the battery sunk but it still continued to start the car until I voluntarily replaced it. Yes, I short circuited a car battery while the car was running and it survived.

Far too much jump starting paranoia out there.

Uniscots97

Ebe, its an automatic so I need to engage the 'drive' before I can move it.

Richard53

TrickyWicky wrote: »

There is no difference. 12V is 12V whichever car it comes from.

<snip>

Far too much jump starting paranoia out there.

To be fair, you did say that was many moons ago. I have been told by Sealey that the big power pack we use in work is not safe to be used on a car with modern electronics. The risk is a voltage spike frying some sensitive component in the ECU or somewhere and costing hundreds to rectify. The method they recommend on a modern car is: connect the two batteries, start the second car, let it run for 5-10 minutes, stop the engine, *disconnect the jump leads*, and then try to start the first car. In effect, the second car is being used as a massive quick charger to put some charge in the slave battery before a normal attempt at starting.

With an older car with points ignition or even a simple CDI unit, these risks are negligible or non-existent.

Personally, I would use a power pack or second car to jump start mine, and accept the small risk of damage. But I wouldn't do it to anyone else's car.

colino

To be fair Richard53, you did say that many moons ago.
How else do you think auctions and traders get tired cars started if not for jump leads and starter boxes?
Well done for Sealey in selling a product to a customer and allegedly then telling them its not safe to use.