There was a recommendation on this forum to buy the AUTOOL battery tester, without thinking I did. Should have done my usual research.
The battery gave some very dubious readings- tested against 4 different batteries - it suggested replacing a brand new and fully charged one among other things.
The implication when I bought it was shipped from I think it was Germany, but when you do the return you suddenly discover you're dealing with a Chinese company.
They gave me the run around asking for video proof, but then never actually looked at the video - basically wouldn't send me a shipping label so I'd have to pay for the return.

When I told them no chance they de-listed the item to prevent me doing an eBay dispute and giving them a negative rating - very sly behaviour. Luckily eBay customer services are onto it.
For 40 GBP don't waste your money. For the fact that they seem to sell a defective product pitched as a European item, knowing it is defective, they deserve all the bad publicity they can get, hence I'm posting on here. Buy a known quality brand from a reputable supplier is my advice - or better still just use a multi meter.