Long shot probably, but does anyone happen to have a multimeter I could borrow and live local to North Swindon?

We have lost the use of our car due to battery being dead and I need to check to see if it just needs a new battery, or if it's a new alternator job. Hopefully the former! Have tried our breakdown, but as it's on the drive, not away from the house, they want to charge £130 for the pleasure! Daylight robbery :-/