Battery light flashing under load??!!

[bh1kh4]

Hey my Cupra the battery light is flashing when under load after 3k revs what could it be?
I've had the battery tested saying its needs changing but it's not given me any probs much but I hope it ain't the alternator?

Any advice pls?!

 

[sockpuppet]

It most likely is your alternator. I had the battery light flash for about 1/2 a second if I was at 4500 revs, I changed the aux belt and tensioner as I thought it may have been slipping, but it still flashed at 4500 revs so I got the alternator refurbed and that fixed it.

 

[bh1kh4]

Cheers for that I'll get that sorted and then see how it goes