Interesting Behavior With Inova T4

Last night I went to my wife's vehicle and started it up. I then grabbed the Inova T4 that we keep in the glove box. It had just been fully charged a day earlier and had not been used since. Anyway, when I turned the switch on I immediately tried to go to the strobe mode, but then shut down. After letting her vehivle warm up about 10 minutes, I tried it again and it behaved normally. The air temperature was about -20 degrees Fahrenheit (-29 degrees Celsius). I did not realize that this could happen in extreme cold temperatures. Is the likely cause the battery, the switch, or something else?

While I don't think Li-ion cells are rated for those temperatures, unlike Li primaries, the cause might be hard to pin down. Let's see what others have to say.