Well there’s the likely answer to your problem then Harry.
£180 for a replacement battery?
Tip (1) :- Type you registration number into on-line battery specialist suppliers such as Tayna or Battery Megastore ( there are others).
They will list a number of alternative makes at varying prices.
Tip (2) :- Buy good quality at competitive prices. I never buy cheap batteries, but buy premium brands and grades at most competitive prices. Beware, even top grades such as Varta/Bosch, Exide etc. have differing grades of the same battery type within their range. I alway buy with at least a 4 year warranty grade. Have been using Varta/Bosch, but bought an Exide (Premium, not Excel-important) and impressed so far.
The supplier will suggest you check the battery dimensions, its capacity in terms of Ah, and it’s Cold Cranking current (CCA) against your current one.
Perhaps you could let us know how much you will save via. this route Harry.
Kind regards,
Gareth.