On 07/06/2021 13:46, Theo wrote:

Not sure if this is the right manufacturer, but it looks like a standard
'UPS' style lead acid battery:
https://www.amazon.com/AmeriGlide-Pl.../dp/B087D6P58C

which are available in the UK for roughly the same price. This supplier has
been recommended on another newsgroup for UPS and their batteries:
https://www.ebay.co.uk/itm/184853002168
I buy batteries from Tayna. They have these:

https://www.tayna.co.uk/mobility-bat...-pair-stannah/

(1 pair of batteries, ~£26 delivered). Tayna seem to be good, and I have
bought mobility svcooter/car/stairlift/motorbike batteries there.