Recommend a 12v battery please

[Iain]

Short runs don't make much difference to an EV. It hasn't had to pump out 3 or 400 amps into a starter motor to get the engine running. all it has to do is fire up the computer and flick the switch on the main battery.
A booster jump starter doesn't need to be expensive. You can pretty much buy the cheapest on amazon and it will be fine. As long as you charge it up each time you use it there isn't much to remember.

Thanks for your response Kevin.
Although I am no mechanic I am pretty sure my battery is not performing as well as it should.
I accept that the 12v battery does not have to pump out the large current that an ice car requires to start it but I suspect the cold weather, heating, lighting and wipers on during a twenty minute run is insufficient to keep the 12v battery in peak condition.
My (perhaps flawed) logic tells me;- 1 Change the battery at £70 to £100 pounds cost. 2 Ask the garage to check for faults £100 plus. 3 Buy a battery booster at £30 to £100 pounds.
Options 2 and 3 may still result in me having to buy a new battery so option 1 seems best.
Happy to be corrected if my old illogical brain is failing as fast as my battery.