Operating Temp of D10 SP R2

[LedTed]

While testing the homemade diffuser I made for my NiteCore D10, I noticed that the flashlight got warm when in "high output mode" for a short while.

After 5 min, the temp at the outside of the head was 131.9 [FONT=&quot]°[/FONT]F.

The AA battery I am using is rated for use from -40 to +140[FONT=&quot] °[/FONT]F.

As the heat source (the emitter) is near the battery, this "hot" situation concerns me.

Would anyone with experience or expertise kindly give me some feedback?

Any help would be appreciated,

 

[SilverFox]

Hello LedTed,

You need to measure the battery temperature and see how close it is to 140 F. With nickle chemistry the heat will damage the cell resulting in poor performance. You will have to get a little hotter to make the cell pop.

One solution would be to limit the run to 4 minutes... :devil:

Tom

 

[LedTed]

Thanks SilverFox,

Now that I have some indication that I have some "room" to experiment with, I'll check the battery temp and see.

D10 Mode = OFF
Time = 0 min
Temp of FL head near LED = 75.3 F
Temp of LED side of Battery = 75.3 F

D10 Mode = HIGH
Time = 10 min
Temp of FL head near LED = 101.5 F
Temp of LED side of Battery = 80.4 F

Hope this helps,

 

[StarHalo]

130-ish after five minutes sounds about right, remember that most batteries perform best when discharging at around 120 anyway. The general rule of thumb is to not operate the light beyond when it gets uncomfortable for you to hold, but if your measurements show that the battery never goes over its max operating temperature, no worries.

There are some lights that do deliberately overdrive, some Fenixes and Jetbeams being good examples; this effect is exacerbated when using li-ion batteries. My EDC, a Jetbeam Mk IBS, when powered with a li-ion gets too hot to hold after about a couple minutes - it's pretty much guaranteed to destroy itself if left on max output for long (but that's how you get 225 lumens from a 1xAA light.)