So, last summer I took my Q8 on a Jeep trip. Had a good time, kinda tucked the light between the rear seat and the fender for easy access and to keep it from bouncing around. A week after the trip was over I went out to the shop to grab my light out of the Jeep and found that it was ON, very dimly.

My charger doesn't have voltage readout, and I didn't think to check them with a multimeter at the time.

The flashlight now seems to go much shorter periods before dropping brightness and I'm assuming this is because of trash batteries. Would protected cells have saved me? Any reason not to buy them other than cost?

I don't have 4 other 18650s to test these against, so I'm kinda going by seat of my pants feeling....