"Charging failure Service urgent" plus red battery light

[Paul Bearer]

Volvo V70 2.4D 2008

For a couple of weeks had a low whine whilst in motion, nothing when stopped, so booked in with local mechanic to see what the problem was but got hit with covid, so could not take it and car sat for 10 days without use

Tested negative so off to the shops, its only 1.6 miles, got there no issues, went to go to another shop close by and a warning came up "Charging failure Service urgent" plus red battery light, so off home I go

Glad to get home without issue, checked with a multi meter, my battery then reading 12.01v, with running engine 13.38 to 13.42v , with fan, lights etc on 13.34 to 13.36v

So it appears the alternator has insufficient output

I am assuming here its the alternator but can't get to mechanic yet as he is booked up, would I be right in thinking the alternator is the likely cause?

And being without any other transport, what are the chances of the alternator dying completely?
I don't want to risk getting stuck but may have to at some point

It had a new battery September 2022

I phoned the nearest Volvo dealer and they quoted £615 for an alternator, I confess I burst out laughing ;-)