Thread: FFRR - Alternator or battery failure?

Thanks mate. I have a charger with a rejuvenation function. I put it on overnight and it seemed to revive the battery. I get it back this arvo and will keep an eye on battery voltage.

I was concerned about it shutting down like happened to Mrs Drivesafe. So I hooked up a multi meter to a cig lighter power source to monitor voltage while driving, which showed constant voltage drain. I also sent the family home with the in laws in case it didn't get home, and it didn't by about 300km.

now that its home....

do the load test on the battery, by cobbling together something that puts a constantish draw on the battery like a pair of headlight bulbs. and monitor the battery voltage down to 10.5 as I suggested earlier.

dont worry if you cant get it exactly right in terms of the draw.

If you post up your starting voltage (let the battery sit overnight or for the day off the charger) the volts and amps (or watts) of what your load was and how long it lasted till it hit 10.5v along with the RC number on the battery someone on here should be able to nut out the math for it to give you a rough condition on your battery.

once thats done and you have the battery hooked back up again

get a clamp meter and check the amps draw on all of the +ve leads off of the battery start the car turn on all the stuff you normally turn on and then post that number up for us.. then we can tell you how long you should have been able to drive the car for

If it was an old school vehicle I would have suspected youve fried the regulator, dropped at least one diode in the alternator or at least one complete winding. It might even be the slip ring brushes lifted off.