Tested 2 × XTAR 4300 1.5V Li Ion cells with the Emisar Kr1AA for functionality and runtime:
The Deets
First cell was used to configure, dial in, and check the max sustainable ceiling, so runtime was done with a partially depleted cell. Also, the cells are designed to sustain 1.5V for as long as possible, then enter a gradually declining “low voltage indicator” mode for devices like wifi cams, etc. The feature seems to work well.
Max sustainable mode for either cell was 104/150. Greater than 104/150 caused the cell’s protection to kick in, and reboot the light to the 1 blink power on boot sequence. ANY mode that exceeded 104/150 caused the same condition, including strobe and lightning storm, etc.
Light config:
Thermal throttling set to 45 Celcius
Max Ceiling set to 104/150
First Cell after configuring, with a total of 4 intermittent on/off sequences to check the voltage
Cumulative Runtime: 95 minutes
- note: each on/off sequence bumped the light back up to 104/150 before a gradual stepdown due to throttling
- Light just cut out and did not turn back on at the end of the test
Second Cell after quick test fail at 105/150, reconfigured to 104/150, ONE intermittent on/off after noticing the light “flickered”, showing a voltage of 1.48, indicating it was now entering low voltage mode.
Cumulative Runtime: 115 minutes
- note: after the voltage drop, the light would not re enter ceiling mode, had to ramp to a slightly lower mode to allow the test to continue. Thermal throttling dropped it lower anyway.
- Light just cut out and did not turn back on at the end of the test
Thoughts
These cells might be a great alternative to NiMH cells if you don’t need any brightness over (in my case) 104/150. You would lose access to the bright modes of Strobe and Lightning storm, as they would trip the protection circuit. They may also prevent the light from going “too bright” while in a pocket or accidental turbo/momentary turbo activation, thus reducing the risk of burning from a focused beam, as documented in another thread as a precautionary tale…
ULTIMATELY, NiMH (or even alkalines) would probably be the safe option if you plan to physically abuse the cells, but if you don’t, these Li Ion cells might be a good alternative with decent runtimes.
Will update with some other comparisons later on after some more tests.
Deets 2
Further testing today, Variations from yesterday:
Environmental:
86F–>64F, 17%–>72% humidity, Still air–>drafty
Light config:
Ceiling 104–>100
Cell1: 76 minutes
Cell2: 71 minutes
Speculation:
Because of the changes in testing environment in addition to a lower starting level, the light did not throttle as heavily as yesterday, allowing for a longer sustained high while reducing the overall runtime.
Summary of results:
Cell1
104/150; 95min
100/150: 76min
Cell2
104/150; 115min
100/150; 71min
