I'd want to use high current cells for that. The normal recommendation for safety is that the maximum discharge rate should be no more than twice the capacity in mAh. So for a 16340 claiming 800mAh it would not be wise to pull more than 1.6A. The protection circuit ought to cut in at such draws.
If the cells are good, they will tolerate this treatment for a while, but I personally wouldn't bet on it. The cells will probably fail benignly but I wouldn't bet on that either. You'd be wise to get some lithium manganese (IMR) cells for that purpose. They aren't that expensive here.
OK that is what I was afraid of. I will just put the stock emitter back in, judging by the weight of this light heat managment will be the next problem. That's good information, thanks Don.
I tried 2 different cells, protection circuits did not kick in.
You know what else is odd Old, I put the same cell in my WF501A with the famous Manafont drop in that draws 3+ amps on a 18650 and it only pulls 1.7 amps.
Hi Old, it is a single mode light and I did recheck it for a short. Once I figure out how to post beamshots it will be obvious were all the amperage is going. I am going to try one of these is my MCU-C7 3 mode to see how it works before I change the driver. Thanks for the help.
Almost every 16340 grossly overstates capacity. The IMR ones seem to be honest, at least the 14500 ones I got from bestinone are within a few percent of rated capacity. Now checking the AW IMR 16340s I have for capacity. Results in a while
Not and measure the result - my charger won't let me discharge at more than an amp. What I can do is measure beginning and ending current on my XM-L modded Mr.Lite J4. It pulls just over 2A at switch-on. The cell measured 568mAh at 500mA discharge but it makes no sense to measure IMR cells at such low discharge rates - that really isn't why they are made.
If it holds the initial current and can hold up at that discharge rate it should give 15 or so minutes on full power. Won't know till I try....
4:45 no perceptible drop in light output but the whole light is warm, not hot.
8 minutes, light output still steady - I have a light meter measuring output. Capacity at least 2000mA x 8 minutes = 16000mAminutes. Divide by 60, capacity is at least 267mAh
10 minutes - still steady 333mAh minimum. Light now hot but still holdable. Now using my hand as a heatsink
12 minutes - still steady - at least 400mAh
14 minutes - still steady output - at least 467mAh
14:50 output down a little - current draw now 1680mA. Will have to do some calculating to work out capacity. If we take the lower value, we still have at least 476mAh at 17 minutes. The light is now cooling - the driver isn't wasting as much energy as heat.
At 18:20, voltage down to 3.8V current draw 1670mA - at least 500mAh. In the time taken to measure voltage and current, light output has recovered to initial level (Measuring ceiling bounce)
20 minutes, voltage down to 3.71V, current down to 1500mA - another 40ish mAh - so overall capacity on a 1.5-2A load is around 540mAh.
So a 100ma difference from AW to generic-for almost double price. For low current, generic wins for value, but at high currents, AW's are almost guaranteed to win.
They also probably charge better: thats the thing with high capacity cells: you can put more charge in faster. Also why IMR are good, if you have a charger that can supply large currents.
Real problem is holding the meter probes in place. I really need to build a jig to do this so I can use the datalogging meter and then get the area under the curve for a reliable capacity. It doesn't help that my high-current meter leads are very, very stiff (3mm2 solid copper). These leads are overkill but make the results more trustworthy.
These cheap IMR 14500s seem to have no trouble providing 3.3A. But the dropin is getting too hot as is the driver and I'd like to try to eliminate those thermal effects.
I'll get it done, just not tonight. I really could use one of those CBA things - but carriage kills the deal here - maybe when I'm in the US in August.