Michael Chare wrote:

I bought some LR44 1.55v batteries on ebay for my Barclays Pin sentry
card reader. They don't work!

Using my digital multimeter the voltages of the 4 I tried are 0.471 1.30
1.43 1.47

What voltage should I get from a new battery?

Some Energizer alkaline LR44s with 2020 expiry date all read 1.57V