NewBie
*Retired*
I have an ARC4+ Rev.2 and wanted to see how long it could possibly hold Level 1.
So I took a bag of ice and set it on top the ARC4, in order to keep it cool. The bag of ice was filled with water, to aid in thermal transfer. I let it cool down for 15 minutes before turning on. During the entire runtime, the ARC4 body ever exceeded 25C. The ice was not on the flashlight long enough to cause significant cooling of the battery, and the battery seems to self heat anyhow (internal resistance losses of the battery cause it to heat, amongst other things).
This way the Thermal Protection of the ARC4 never kicks in, and it will try and hold the Levels, until the battery cannot support the current/voltage requirements to hold the current level.
The test started at Level 1.
This data is not smoothed or doctored, so if you look carefully, you can see the battery even recover a bit after a level drop, which causes the brightness to come up a bit.
I used this meter ExTech Heavy Duty Light Meter for my measurements. Notice it has a PC interface, so the datapoints are actually the Lux readings from the meter.
The measurements are taken every three seconds. The readings are at a 1 Meter distance. The lens was freshly cleaned, and there was at no time any condensation on the flashlight.
Note, runtime will be shorter than shown in TIN's graphs, as in his tests the ARC4 quickly kicks down to lower levels due to heating, which extends the time at the lower levels (e.g. Level 1 kicks down rather quickly, which depletes the battery less).
Due to the long time in the above graph, I decided to expand the ARC4 Level 1 section of the plot. At 27 minutes, you can see a line dropping vertically, which is where it kicks down to Level 2.
I did not use any datapoint smoothing options or trend lines to make it look smoother than it really is. The light output is really moving around like this, as an emitter on a heatsink shows a rather smooth plot. This amount of wiggle is *not* noticeable to the eye, but it is there.
So I took a bag of ice and set it on top the ARC4, in order to keep it cool. The bag of ice was filled with water, to aid in thermal transfer. I let it cool down for 15 minutes before turning on. During the entire runtime, the ARC4 body ever exceeded 25C. The ice was not on the flashlight long enough to cause significant cooling of the battery, and the battery seems to self heat anyhow (internal resistance losses of the battery cause it to heat, amongst other things).
This way the Thermal Protection of the ARC4 never kicks in, and it will try and hold the Levels, until the battery cannot support the current/voltage requirements to hold the current level.
The test started at Level 1.
This data is not smoothed or doctored, so if you look carefully, you can see the battery even recover a bit after a level drop, which causes the brightness to come up a bit.
I used this meter ExTech Heavy Duty Light Meter for my measurements. Notice it has a PC interface, so the datapoints are actually the Lux readings from the meter.
The measurements are taken every three seconds. The readings are at a 1 Meter distance. The lens was freshly cleaned, and there was at no time any condensation on the flashlight.
Note, runtime will be shorter than shown in TIN's graphs, as in his tests the ARC4 quickly kicks down to lower levels due to heating, which extends the time at the lower levels (e.g. Level 1 kicks down rather quickly, which depletes the battery less).
Due to the long time in the above graph, I decided to expand the ARC4 Level 1 section of the plot. At 27 minutes, you can see a line dropping vertically, which is where it kicks down to Level 2.
I did not use any datapoint smoothing options or trend lines to make it look smoother than it really is. The light output is really moving around like this, as an emitter on a heatsink shows a rather smooth plot. This amount of wiggle is *not* noticeable to the eye, but it is there.
