OT new alternator needed or low battery?

ARW · 2021-12-19T09:06:46+00:00

So I used the car for the first time in 4 weeksThe charging light came on when I started the car and put on the air blowers and back window de-icer but a giving it 3K revs cleared it.Did 65 miles to the pub and 65 miles back with no problem.Or was my passenger correct in that it was ice on the belt?The passenger is an experienced old codger