Hi,
I just repaired two NB2L li-ion batteries from my Canon cam that weren't charging at all. OTOH, I'm tired to buy €€ 9V batteries, so I decided to give them a second chance with a 9V powered device. The NB2L are rated 7.4V and I have a spare charger.
The LCR tester was a good candidate. I did some measurements on mine, it detects a weak battery at 7.4V and works fine above this value. However 7.4V looks a bit high regarding the ver 1.12k user's manual that says 0.8V above 5.4. Any clue ?
So far so good ! The batteries are within the acceptable range. If the tester keeps working satisfactorily, I'll finally get rid of these medieval 9V batteries !
regards