On 14/12/2020 13:04:50, R D S wrote:
Our car is stop-start, it hasn't performed this 'feature' for many
months. I believe this to be a symptom of the battery not being at it's
best.

It was clicking the other day rather than cranking the engine over,
worked OK upon retrying.

Which is a strange behaviour of a battery and more likely a bad
connection or faulty starter. Especially if more of a "clonk" than a
'click'.

Taken it for a couple of decent runs since
(because it's been largely short runs all year, due to the obvious),
it's been OK.

I happened to have a meter in my hand today so checked it and it's
reading 12.1v which is quite low. Battery life generally being 4-6 years
and us having had the car 4.5 years i'm thinking shall I just replace it?

What is the voltage with the engine running. 12.1V is what I would
expect when the battery has been rested for a while powering the normal
load with the ignition off.

Advice is to trickle charge it first but I haven't a charger and I don't
want to buy a charger *and* a battery.

A charger is always worthwhile having in your toolbox.