Nitecore D10 Battery Question

Hi everybody,

I have done a lot of reading here but this is my first post!

Based on my reading here, I recently bought two flashlights. I use these primarily for walking my dogs because my neighborhood doesn't have lighting. I have a Nitecore D10 and Fenix L2D Q5. I use NiMH batteries (Eneloops) in both. I like to have plenty of light when walking so I use the highest setting on the D10 and the high (not turbo) on the Fenix.

My walks generally last about 30 minutes. The Fenix, with its two AAs runs very cool. By contrast the Nitecore with its single AA gets pretty warm. It almost feels like much of the heat originates from the battery itself, not the emitter. If this is the case I suspect it is not very good for the life of the battery. Can someone elaborate on little on why the D10 runs so much warmer? Is the increase in heat due to the fact the Fenix is powered by 2.4V as opposed to the Nitecore's 1.2V?

Another question is if I powered it with LiIon 14500, would it reduce the heat somewhat?

Thanks for any help!

Hello, I use a 14500 in my D10 and it reaches 106 F after 10 minutes. Using the light on high will generate heat from the emitter as well as the battery because of the hight current draw.

D10 needs to boost the voltage further (300% rather than 50%). Therefore the boost driver in the D10 is less efficient than the L2D, so generates more heat. The higher current draw from the single AA (obviously, double the current draw than from 2 cells) means that some power is dropped across the internal resistance of the battery, heating it up.

Using a 14500 means it has to boost less far, but it also sends more power to the emitter, so generating heat.