I saw a pack of coin batteries in Poundland the other day. At least 10 in the pack, two of which were the right one for my key.
All I'll say is - don't bother! Within minutes of fitting them, they both created the •Key Battery Low• message on the dash!

Oh well. It was only a pound!

Yep, goes for most batteries in there TBH. They tend to be the ones which don't pass QC. A pack of 20 AA from Toys-R-Us lasted longer than a pack of 100 from quidworld. A "new" 9 volt block one fresh out of the packet measured 6.8 volts on my Fluke meter. An old adage I know, but there's a reason why they're a quid.

Think how much money they are making though. I mean- who's going to take anything back for a pound?

Had the same fault. Got mine from toolstation 89p I think.
So far so good
Jake 2003 Range Rover Vogue 4.4 on Gas
1961 88" 2.25 diesel - George
Gone - 1997 3.9 V8i Discovery - Burt