Knackered battery or something more serious
Discussion
Ok so my wifes 2008 1.2 corsa wouldnt start this morning. Central locking dead but as soon as i connected jump leads it fired up no problem. No lights or anything have been left on and the car is driven every day. As far as im aware its on the original battery. Is it likely the cells in the battery have just gone bad as it wouldnt start after work but jumping worked no problem. Car is on 39k miles . Anyone any ideas?
Cheers
Cheers
Gemmot said:
Gents, thanks for the quick replies, much appreciated. Any tips on changing the battery or is it just a case of whip out the old and in with the new?
Check whether you have a radio, immobiliser or alarm that will need to be reset/recoded after you replace the battery. If you have any doubts, you can use a separate 12v battery to keep the system powered up while you replace the main battery. Professionals would use a device that just plugs into a lighter socket for this, but any way of applying 12V safely would do just as well. If you haven't done this before and are planning to buy from a normal retail outlet, consider choosing one that offers a free fitting service. This is one of those jobs that only takes a couple of minutes to do right with the right equipment and will often be offered as a courtesy - which can save you a lot of hassle if you are not familiar with this job.No argument with the above, but some investigation might put off the day for a new battery.
With the battery fully charged, and the car turned off, how many volts at the battery?
Should be at least 12.6V, any less and yes, it needs another.
BUT, is the alternator charging it? With the engine running, do you get at least 13.6V, measured at the battery? If not, the alternator, or the wiring or the alternator drive belt (!) needs attention.
If these all good, is there a drain on the battery when the car is standing? You need a multimeter for the above, in Volts mode, now set it to Amps. With the car turned off, connect it between the battery terminal (either) and the cable, and disconnect the cable from the battery. Any current to the car is now being measured by your meter. It should read a lot less than one amp, as low demand devices draw charge, the radio, clock or alarms systems. Check by opening a door, to activate the courtesy light, which will draw say, 2A or so. DONT START THE CAR! If the drain current is more than hundredths of an Amp (0.001 to 0.009A) then something is on when it shouldn't be and is draining the battery. Courtesy lights are a common one especially the boot as you don't see it.
Good luck!
John
With the battery fully charged, and the car turned off, how many volts at the battery?
Should be at least 12.6V, any less and yes, it needs another.
BUT, is the alternator charging it? With the engine running, do you get at least 13.6V, measured at the battery? If not, the alternator, or the wiring or the alternator drive belt (!) needs attention.
If these all good, is there a drain on the battery when the car is standing? You need a multimeter for the above, in Volts mode, now set it to Amps. With the car turned off, connect it between the battery terminal (either) and the cable, and disconnect the cable from the battery. Any current to the car is now being measured by your meter. It should read a lot less than one amp, as low demand devices draw charge, the radio, clock or alarms systems. Check by opening a door, to activate the courtesy light, which will draw say, 2A or so. DONT START THE CAR! If the drain current is more than hundredths of an Amp (0.001 to 0.009A) then something is on when it shouldn't be and is draining the battery. Courtesy lights are a common one especially the boot as you don't see it.
Good luck!
John
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