Originally Posted by
znomit
Get two and compare one with flat batteries and one with fresh? Its really hard to make meaningful comparisons when you have to stop and swap batteries.
Or measure the battery voltage over its useful runtime and run off an external power supply, comparing the different voltages.
Of course, I expect this thing is plenty bright enough even when nearly drained, so who cares?
It's still very bright, until just before it goes out.
I'm used to seeing white spots for ages, so the red ones make a nice change.
BTW, you should always look directly at a high power LED to check it is working and see how bright it is..
Anyway, how about this - I've got some solar panels that output a few volts when I shine a torch on them.
Assuming they collect red light, I could set up the torch a few inches from one and measure the voltage produced by the solar panel every 10 mins for 4 hours.
Obviously the initial highest reading would be 100% and the lowest reading (if any) would be 0% when the light is off.
I'm not sure the output is linear so 50% might not be 50% but it would indicate how long the output is constant and how quickly it drops - a graph might be interesting ?
Any thoughts on this test procedure ?
I did this with my P7 on low to check if the output is regulated and there was no drop at all - but it does have a higher input voltage (2 x 18650).
