A few weeks back Amazon.ca offered a few Nitecore EC4S’s for a very low price - I think it was around $30. Never one to pass up a bargain, I grabbed one.
I recalled hearing parasitic drain stories regarding this light but not having the technical savvy to measure it, I tried my homespun method.
I charged up a pair of ‘young’ Panasonic 18650B’s to 4.20 v. and then ‘ran the edge off’ to 4.07 v. I put them in the EC4S on July 5 at 0900 hours and set it aside.
Starting at 4.07 v.,
After 100 hours, the batteries tested 4.06 v.
After 175 hours, the batteries tested 4.05 v.
After 270 hours, ” ” ” 4.05 v.
After 325 hours, (July 21) they tested 4.04 v.
I don’t know how bad that is; it doesn’t seem terrible to me but I don’t have the math skills to determine a proper rate of discharge. That’s 1/100 of a volt/week, so unless I’m missing something, it should be alright for a quite a while.
If I were setting the light aside for a lengthy period of weeks or months I’d no doubt take the batteries out - but it wouldn’t seem to be significant over the course of a two-week expedition, for example.
Any opinions, higher math calculations, or experiences with this light would be appreciated. I don’t have any self delusions about my redneck science experiments.