Charging a battery

Raxiel

Does the cabin have a light that 'dims' once you close the door, rather than a simple on/off?
I've heard of instances of those malfunctioning and continuing to drain even when off. Try setting the physical switch on the light to the off position and see if it helps.

May not be the issue, but easy enough to do.

arcon5

If it didn't do it at the garage you sure your not not shutting doors or glovebox something properly?

The voltage output at idle and running is usually within half a volt anyway. The output is regulated and idle voltage is always the minimum required voltage for the charging system.

maxmycardagain

To jump start dont expect your £10 Halfords leads to carry the 200amps required to REALLY jump start the sick car, put the leads on (red-red, black-black) start the donor vehicle and run it at over 1000 rpm for at least 5 minutes... then try the sick car, if you have proper jump leads (£40 from Machine mart) and heavy duty clamps it is possible to "jump" off any battery if its good enough...


id get the battery "drop tested" to check its charge holding and also have the alternator output checked (with a multimeter) looking for over 14 volts with engine running at 1000rpm

maxmycardagain

or........ after a run, take a battery lead off overnight to see if the van/interior lights/immobiliser are draining it


it could be a dodgy starter or even the earth strap to the engine at fault

mchale

Norman_Castle wrote: »

Buy or borrow a battery charger. The alternator is designed to keep the battery topped up, not to fully recharge the battery.

Rubbish, the purpose of the alt is to charge the battery.

Begsey

mchale wrote: »

Rubbish, the purpose of the alt is to charge the battery.

It charges the battery, and runs the cars electrical equipment when the engine is running, but won't charge it to the same extent as a battery charger.
That's why the battery the OP had fitted lasted 5 days. By day five, it hadn't been recharged enough to keep going.

Edit to add, here's what Optima say.

https://www.optimabatteries.com/en-us/experience/2012/08/fact-alternators-are-not-designed-charge-dead-batteries

Or a quote from the article.

"Alternator manufacturers know the same things about alternators that we do- they are designed to maintain batteries that are near a full state of charge, not recharge deeply-discharged batteries. We post this on message boards all the time, but there are still folks who are convinced their alternators are designed to recharge deeply-discharged batteries."
A battery that can't start a car, is deeply-discharged.