I have to point out there is no "loss in efficiency" that affects runtime when we are calculating runtime based on battery current(as in amperes, A) and capacity (as in ampere-hours, Ah). Any losses exist outside of this equation. Inconsistencies in the outcome of these calculations are mostly caused by inaccurate initial values and simplifications.
variation between individual cells
actual driver current draw not exactly matching the driver specification or any other assumption
measured tail cap current not matching the current through tail cap and switch
variation in final cell charge voltage
using a nominal capacity rating or a measured capacity not matching the discharge rate
cut-off voltage or the point of lowest discharge
Examples of variables that are not at play here:
driver efficiency
emitter wire losses
any properties of the LED itself
What I'm stating only applies to true linear regulated drive(even if many parts of this apply to any buck driven light etc, it's just more complicated). This is also before we account for the fact that such a circuit will function in a non-current-regulating mode for a good while towards the end of our total runtime. The regulated runtime will typically be shorter than capacity-calculated runtime, and total runtime will longer.
None of this has to do with electrical losses or efficiency per se. These calculations will be inaccurate even when using a hypothetical cell that has identical capacity at any discharge rate. There are electrical losses in every component, but they have no effect on the runtime-capacity-current calculation in a linear regulated (and hard switched to be accurate) flashlight.
It's a good design practice to assume 90% or even 70% factors when making a design calculation and considering whether the final device will be adequate, but it's unrelated to this issue.
This is all about the Kirchhoff laws. Voltage losses are not current losses and do not cause current losses. Current losses do not exist.
I was having difficulty deciding how many chips I wanted in a few Convoy M2 I bought last year. My concern was heat, so I went for 7135*6. After some reading here and suggestions by some members I decided to go for a maximum current (7135*8) for S2+. I use light on medium or low most of the time which suits my needs perfectly and I still have high for a short time if I need it.
I think it all comes to your actual usage and preferences.
Good thing there’s many configurations to choose from
It finally turned up. My replacement S2+ In black 2100MAH. The mid mode seems brighter than the old one, I know the old one may of only put out 30% as a 2500MAH lasted 3 and a half hours before low battery blinking.
I think this one may run at 40% or even 50, it is much more useable one mid (not that the old one wasn;t bright, just this one is. Same config as the old one I guess, 2 chips I can see and 4 underneath, but I am not checking to make sure this time lol)
Its bright, does what I want, and I even got an attachment for my bicycle. I will have to remember to dip it and point slightly left, don’t want to dazzle any other drivers, give them another reason to hate cyclists lol.
I forgot to add, even if I don’t do anything with the other body, once the black one is battered, I can just swap the pill and have a new looking torch :).
You might try completely disassembling the broken one (remove all O-rings as well), cleaning with soap, good rinse, and dry. Place all the black anodized parts in the oven and baking it for a while.
would that work even though the two thin wires that power the LED are missing? As I don’t want the family to finally think I lost it cooking parts of a torch instead of dinner for it not to work lol.
When baking anodizing you remove everything except the bare aluminum shell. All parts. O-rings, lens, reflector, led, driver, pill, switch, switch retaining ring. Also clean up any thermal paste left under the led (if the light has a integrated pill) and any grease / lubricant on the threads or o-ring groves.
I have the grey violet smoke tinted version… With 2800ma driver… And I have a tn12 2014nw… Although they differ in beam pattern (the Convoy it’s all flood) I must say the Convoy does have just slightly lumen less… I think a hundred or even less.
Regarding the tank 007e09 with Ladda ikea and eneloop AA it’s brighter on max than my 2800ma Convoy on low, and has even a better throw (s2+ being on low)… Also the tint of the tank it’s marvelous… I love that light…
My S2+ has xml2 t6 4C tint which is good if you look at the beam alone… And maybe too warm if you compare to the tank e09… Also being a t6 should put even less output than a u2…but again… It holds decently against the tn12 2014….which is absolutely better in any way but costs 4 times as much…. So…
Or like others have said.....you could just order a driver of your choice with your own custom modes and a new LED and put that host to good use. One is never enough :)
The S2+ is a pretty dang useful light. I honestly love mine… its my 2nd most used light after my Streamlight Microstream and Pelican 1910. If Simon/Convoy ever produced a 14500 or 10440 (AA and AAA) sized light, I’d buy half a dozen in a heartbeat.
