Are Longbow Micras Thermal Protected?

[357]

I just got my new Longbow Micra with bush-putton switch, and out of the mailbox it was very hot. When I took it out of the package, it wouldn't start. Checked the battery connection, still wouldn't start.

After panicking and thinking that it was broken, I gave it one last try after waiting 15 minutes and bingo, it worked! I'm trying to decide if I have a faulty switch or if thermal protection caused it not to work immediately. This is my third Longbow, and the first with push button--all the others have the twisty so this is new territory.

 

[AK]

Is it possible that the battery was close to dead? I've noticed that after running my LB on a depleted battery, if I turn the light off and then try to turn it back on, it won't light up. However, if I let the battery rest for a few minutes, it works.

 

[evan9162]

Lithium batteries have a PTC (positive temp coefficient) thermister on board to prevent the cell from exploding under high current. It is basically a resistor that goes up in resistance as the temperature increases. The temperature of the cells may have been very high, thus causing the thermistor to be a high resistance value, limiting or preventing any current flow from the batteries until they cooled off.

 

[357]

The battery in it were fresh (came with the light), plus I tried one other battery that I know is fresh and neither lit it up initially while it was hot. Once I gave it a rest, it lit up with both batteries but occasionally flickered a bit. Right now, its working fine (no flickering). I'm going to keep an eye on it, and if the symptoms reoccur I'll ship back to Battery Station for replacement.

 

[Lumen]

My Micra does the same thing when it gets hot too. It flickers and if I turn it off, it won't turn back on for a while. Really iritating when you need light. You know that you can't turn it off, but you do so anyway out of habit of conserving batteries, so your're just kinda stuck there in the dark for a while until the battery/light cools off.