I really don’t think a protected cell will protect against reverse polarity. The protection circuitry in the battery is designed to protect the battery, not the flashlight.

For this light to put out 2000 lumen I think the amp draw on the driver would need to be around 8 or 9 amps. (Maybe even higher)

My guess is that 2000 lumen is very optimistic. Lumintop does have a boost driver in their ODF30 that can pull 8 to 9 amp. I don’t know if they are using the same driver design here or not.

If you try to use a protected cell you can bet the amp draw will be higher. This is probably why your batteries protection circuitry tripped.

Lumintop has a 26650 protected cell with a higher trip point. It seems to work in the ODF30, but only until you loose a little voltage, then you loose turbo.

For best performance you want to be using aN unprotected high drain and to bypass the springs. Even then, I don’t know if it will deliver 2000 lm.