Dead Battery

Uniscots97

I need a bit of help please. My car was off the road last year for around 6 months due to lack of work. When I put it back on the road, the battery (the original and its an older car) wouldn't keep a charge. So I replaced the battery and ran her intermittently until its MOT in dec, which she passed (with a little bit of work). I was then in hospital for a while and tried to start my car at the end of last month and she had to be jump started. I only did a short journey to the shop. I tried to jump start her today but due to the on-set of the weather couldn't leave it on the donor car for more than 2 mins, and the car cut out. How long should I be leaving the car connected to the donor car for before it will stay on? and how long would I need to run it for (i.e. drive it) to charge the battery back up?

nickcc

Just buy a cheap trickle charger from the likes of Amazon for under £5 or if you have no power available you can buy a solar charger for £13.50.

Uniscots97

thank you nickcc

EdGasket

Jump starting a modern car is not recommended. You can blow one or both cars up in the process (well the electronics that is). Get a charger and either remove the battery from the car or if you are leaving it in the car, disconnect one terminal while it is charging and only reconnect when the charger is disconnected so you don't blow anything up (chargers can also blow electronics).

Uniscots97

Do you think I'd be able to jump start it until this trickle charger arrives? If so, how long would I need to leave it connected to the other car?

nickcc

If you disconnect the battery you may need the radio code.

nickcc

Uniscots97 wrote: »

Do you think I'd be able to jump start it until this trickle charger arrives? If so, how long would I need to leave it connected to the other car?

Once your car has started the alternator should be providing sufficient power for the engine to run so you should be able to disconnect the jump leads as soon as your engine starts. Make sure anything that uses power is switched off (except the ignition ) or it will take longer for your battery to charge. A good run of at least 30 minutes should be sufficient to partially charge the battery.

forgotmyname

If the battery is really flat then the alternator may not charge it. It needs some voltage for it to do its job.

With very little voltage it may think the battery is missing.

[Deleted User]

Uniscots97 wrote: »

I tried to jump start her today but due to the on-set of the weather couldn't leave it on the donor car for more than 2 mins, and the car cut out.

Are you saying that, as soon as you disconnected the donor car, the engine on your car died?

Uniscots97

Yes Bob, but I'd only started donor car connected my car and started it, I didn't leave it for any length of time. I'm guessing that is the problem?

TrickyWicky

Uniscots97 wrote: »

Yes Bob, but I'd only started donor car connected my car and started it, I didn't leave it for any length of time. I'm guessing that is the problem?

IT shouldn't be as long as you keep your car running. Your car only needs enough power to crank the engine and start it and once it's running your own alternator should provide enough power to keep it going and recharge it's own battery.

It sounds to me like you may have another duff battery if you ask me. If it's been left flat for a long time then that may well be the cause as flat batterys and cold outside weather to not mix. I speak from experience. It doesn't matter how new it is, if you let it discharge and leave it out in the cold it will be dead within a month.