Car still sitting unused (hope to be out in it next month subject to a fresh MOT) so checked the battery voltage with my cheapo Amazon accessory socket Voltmeter.
It's showing a fairly healthy 12.2 Volts due to fitting a new 75AH Yuasa YBX5069 (£92 direct from Tayna's website) slightly down from 12.4V when I fitted it 6 days ago.
The previous 6 year old YBX3014 was still essentially "ok" (just before removal it had started the car easily with a reading of 11.7V after a full off car charge 9 days previously IIRC) and I probably would have stuck with it for longer if car was still my daily driver.
However car hasn't been used since November and moving it every 3 or 4 weeks to stop the (overinflated) tyres flatspotting became a tedious ritual of opening the car manually / setting off the alarm / removing the battery to charge it / temporarily fitting a supplementary (motorcycle) battery to silence the alarm......


Admittedly it seems that some of the time this was also due to an ageing fob battery 🙂 (CR1632 now also replaced) but with BOTH batteries replaced things are looking alot better generally for a car that will now only see occasional use.
On the slight downside the bigger beefier (15 AH extra capacity) 5069 weighs an extra 3.2Kg.
A point to note if you're interested in a YBX5069, it's officially 272mm long (12mm longer than the battery tray) but the "footprint" is only around 255mm.......