jetbeam parasitic drain?

i have a 3 mode (each mode infinitely adjustable) jetbeam 18650 light (not sure exact model 3M ?)

recently i have kept a cell in it, and when i went to use the light it has cut off/out quickly, (15 minutes on high)

cell was at 14.1v when light cut off

do jetbeams have parasitic drain issues or might it be my battery?

Nearly all light with a regular tail switch has no parasitic drain, including JetBeam. The problem is either something with the battery or something with the light.

What kind of cell has 14.1 volt? Or did you mean 4.1 volt?

Can the light work on a single cell or does it need two CR123 batteries?

i think i meant 4.1v (when it cut off)

Could it be a bad cell?
Yesterday I found some old (2-3 years) AA NiMh that I havn't used/charged in at least a year. When I tested them they measured about 0,5 V. I put them in the charger and in about 10 min the green light showed that they were fully charged. I put them in my TK20 on turbo and after about 30 sec it went down to general and after 5 more min it was really dim. The cells still measured 1.27 V.
The next (healthy) set of batteries took several hours to charge (as it usually does) and works fine.
The bad batteries were som cheap "NoName" and I put them in my recycling box.

I know that your cell was a Li-Ion but I guess the behaviour is similar when they get old/bad. They can probably keep up good voltage when not under load but as soon you turn on the light the voltage drops.

waddup said:

i have a 3 mode (each mode infinitely adjustable) jetbeam 18650 light (not sure exact model 3M ?)

recently i have kept a cell in it, and when i went to use the light it has cut off/out quickly, (15 minutes on high)

cell was at 14.1v when light cut off

do jetbeams have parasitic drain issues or might it be my battery?

Click to expand...

A healthy click switch should not have any parasitic drain. Does the cell self discharge if it is left sitting outside the light? This is one of the checks I do with 18650 cells, jsut charge them and let them sit for 3-4 weeks.

4.1V is almost a full charge. If you have a DMM, definitely measure tailcap curernt draw. If a healthy ~2400mah 18650 cell is dumping in 15 minutes that equates to a ~9 Amp draw (!!). I can (almost) guarantee you your cell is not producing that kind of current... you'd probably observe other oddities besides a short run times.

Whats the condition of your DMM? I had some old probe cables that had an internal fault and were giving me all kinds of crazy readings. I was going crazy trying to figure out what was wrong with my lights and cells.

I am willing to guess its the 18650 cell. I had old tired 18650 cells (laptop pulls), that accepted a full ~4.15V charge, terminated just fine and even held that charge for 2-3 weaks. But they had almost no capacity... like ~600mah. Do you have a known good cell you can compare it to? This is the one area where even an entry level hobby charger investment can pay off. Most have a miliamp-hour (like) display that gives you a ballpark idea how milliamps you are pumping into the cell(s).

yea i have a triton 2 charger and a cheap dmm and some AW 18650s,

guess ill do some testing




later :tired: