Battery or alternator?

Well another day another rangey problem!

Drove to work today no problems. Finished at 5 got to car and found the battery was flat as a pancake! Dash lights wouldn't even come on and key wouldn't turn!! Put it down initially to a usb charger I leave plugged in which remains constantly on but to be honest not convinced that would kill the battery so much.

Anyway jumped it and drove 20 mins home; got home settled on drive then tried to restart car... Completely dead again!

Battery's on charge at the min and I'm waiting on a voltmeter to get dropped round. Read various write ups on the alternator etc which I could do with it not being! I'm guessing that the alternators either not charged it up or the battery's not held its charge.

Does the l322 have an alternator fuse anywhere and what's the best way of testing the battery/alternator?

Gonna plug the fault reader in when battery's charged see if that gives me a clue! 😣

Cheers guys!

A 20 minute drive won't charge a battery that was flat and then jumped!

Pull the fuse to the HEVAC, if the battery remains charged, the Final Stage Resistor is buggered...

If that still doesn't cure the drain, next thing to check is the headlamp wipers are parking correctly....

The alternator should charging at around 14.5V or thereabouts!

When my alternator went, I had a giveaway squeaky sound from under the bonnet. Thought at one point there was a mouse living under there until the Transfail prog message came up! :bounce:

Saint's right -

Easiest check once battery is charged (should be around 12.6 v) is to start up and check the battery voltage again, should be around 14.5 v (Alt charging voltage). If its not then check your Earth, but since she started up and its common with the SM then doubt thats the issue.

Id check the wiring up to it as well - make sure you have your signal light wire (to the rear of the rectifier) is at 14.5v and your light is off. Volt Drop test the rest.

If nothing else then the Alt is packed in

What Saint.V8 said plus a duff alternator can flatten the battery in no time flat if a diode shorts. You cannot fully charge a flat battery with an alternator in less than about 12 hours.
USB power adaptors can fail and draw highish current and even melt, I would never leave one live in the car when unattended.