Originally posted by marcusBMG
It's an analogue device, the needle is pushed a bit further into the green by an alkaline non-rechargeable but otherwise no difference in use NiMH/alkaline.
According to reviews, it will work with rechargeable batteries, but a 1.5V battery would be considered just OK or Weak if it were measuring 1.2V on a rechargeable cell. I guess it all comes down to if you're okay with interpreting what is red/yellow/green for something designed for 1.5V, not 1.2V, or if you want to know the actual voltage without having to interpret. I used cheap analog meters for years, but once I upgraded to a digital multimeter, it's hard to accept the vagueness of a needle on a big band of green goodness.