Got a jumpstart, now can't start again

braun_2

Following on from my last thread... https://forums.moneysavingexpert.com/discussion/4725747

My car would not start for 2 days, possible battery or alternator or starter motor.

I called out breakdown and was charged £50 and was given a jumpstart. Took it out for a 15 min drive and let it sit on the road for 15 min to charge the battery, no air con or anything, just engine running for 30 mins.

Put engine off then tried to start it again and it still won't come on... I was under the impression I only needed 10-15 mins to get enough charge into the battery to restart the car... am I wrong? Or have I got a bigger problem such as alternator?

fivetide

Just idling the car is essentially just keeping going. It is unlikely to charge the battery by ticking over, especially a flat one.

You'd need to give it a decent 30 minute run and get some revs in to have a chance of getting it going.

Mind, if you do suspect the alternator then it won't make any difference because it won't have done a thing.

Is it an auto? If not, bump start it and get it round a garage to check it out.

Or get a new battery. I am sure one new battey would be less than two call outs to the recovery at £50 a time.

braun_2

I feel really stupid now as I've basically just paid £50 for nothing, as I still haven't diagnosed the problem.

facade

Didn't the breakdown test the alternator?

Depending on how much money you want to throw at it:

1) Buy a battery charger and a long extension lead, and one of those big rubber flaps to take the wire over the pavement and stop people tripping up (about £7 at wickes) charge the battery.

Turn on ignition, red battery light should come on, start car, red battery light should go off, with nothing switched on, you should measure near enough 14V across the battery terminals if the alternator is ok.
If it wont start, buy a new battery. If you don't get near 14V fit a new alternator.
(now you have a battery charger)

2) buy a new battery, fit it and repeat the voltmeter tests. If you don't get near 14V get a new alternator. (you now have a spare battery if you can charge it )

3) Buy one of those portable jumpstarters from Aldi for about £30. Jumpstart the car, and do the voltmeter checks. (You now have a jumpstarter, don't forget to charge it each month)

4) pay for a jump start and drive to a garage, get them to diagnose & repair.

richard734

I would guess at a dead battery. I had this, AA restarted me, but the battery wouldn't hold the charge at all. Had to get a new battery fitted.
get another jump start from a neighbor or friend with a set of jump leads, and go to your favorite battery/tyre supplier.
Europarts are very decent on price around our way (Milton Keynes) and will fit for no extra charge. (pun not intended!)

braun_2

Thanks to all replies,

I've put my car into http://www.eurocarparts.com and its got a battery for 30 quid... anything I need to check spec wise or should that just fit?

Thanks again.

Quentin

Get the old one tested before buying a new one.

braun_2

How do I do that? Car is sitting out side and won't start.

I measured it the other day and it was reading 12.5v ignition off and around 14.5 this morning with ignition on. So it does charge? but that doesn't mean its holding the charge?

Strider590

braun wrote: »

I feel really stupid now as I've basically just paid £50 for nothing, as I still haven't diagnosed the problem.

It's the battery and £50 would have got you a new one.
Not aiming directly at you, but this sh*t drives me mad, people just will not accept that a battery can read 12v and still be knackered.

facade

braun wrote: »

I measured it the other day and it was reading 12.5v ignition off and around 14.5 this morning with ignition on. So it does charge? but that doesn't mean its holding the charge?

I take it "ignition on" means engine running?
Sounds like a dead battery and an ok alternator.

Buy a new battery and fit it. Remove the negative treminal first, and refit it last.

Likely you will need to enter the code for your radio, and reset any electric windows (simply wind all the way down, then wind all the way up and keep the switch pressed a few seconds)

Technical_Dave

Voltage test of a car battery means pretty much b*gger all. You need to do a drop test to see if it's any good.

A drop tester is basically a giant resistor which measures if the battery can supply a good voltage at high load. Any half reasonable garage will have one. Takes only a few seconds to check.

But for god sake stop arsing about and buy a new battery!