@oweban THANKS!
I’ve read that line a fair amount of time over past year / 2… maybe on this forum? about the mAh number being how much you can get out of a battery in 1 hour…. I’ve been mildly techie for my whole life. I always thought that rating was more of a midline calculation of capacity - you can get x mA over y hours multiplied together. (not trying to pull the max for 1 hour, but more that you can pull, maybe 300mA for 300/2200 = 7,3 hours for a 2200mAh battery
And figured that at either end of the spectrum, things fall apart - ie, you can’t draw 1ma for 2200 hours because the battery naturally loses charge over time and it will be losing charge as you draw that tiny current? And you can’t pull 8800 mA for 15 minutes because of limits of the chemical reaction, heat, etc.
Would you know? Is that a) ‘conventional wisdom’ or b) battery makers actually intend the mAH number of a battery to mean max over 1 hour?
A quick google had some sites mentioning x mAH for 1 hour. Others - this one spells out my thinking I think:
And along the same lines, the rechargable batteries in UPSs, emergency lighting, etc. that capacity can’t really mean amount in 1 hour? I would think different chemical processes just aren’t made for high current as well as others?
If you have a room full of lead acid? batteries storing your solar cell power - that has lots of capacity. I doubt you can draw that max capacity down in 1 hour?
Sorry, a) don’t mean to shoot the messenger b) I’m going on too long : )
I looked through the 18650s I have. most say 2200mAh. 1 I just pulled says 1500mAh. a couple don’t have any markings ; )
Some sets of numbers from 3 of them (I left off things like 18650 and 3.7v (although 1 I saw said 3.6/4.2v (I think that’s the nominal voltage and charging voltage?):
MH61647
SZNS HO2N161EJ 514345
FST 7042315 09950 CJ
So 1800 lumens won’t look much brighter than 1000 lumens? : (
And yeah, all the calculations / terms has my head spinning. And the tightness of the cone (sorry, don’t know all the terms) has a huge impact on how bright it looks - I have some kind of a 18650 with a sliding focus sleeve. Make it a tight circle of light and it is much brighter than when it’s as wide as possible. But the LED hasn’t changed / amount of light being put out by it hasn’t changed.
Admittedly, not that it’s a huge difference in price, but me being me…. I have to ask - what do you think of, in the interests of cheapness, getting L2 flashlights rather than SST40s? This SST40 I just got was $15 deliverd. I have too many now, but the last XM-L2 I bought was $12. I’m likely not going to pop for the higher output 18650s so the SST40’s max output is going to waste?
I’d say though - if the SST40 is not running at max output with these cheapo batteries, it will live longer than the XM-L2 running closer to its max? And then the argument…. I’ll likely lose it before the LED reaches its end of life : ) ???
Oh, check this out. Googling the battery you mention, I come up with this:
https://rechargeablepowerenergy.com/products/lg-mj1-3500mah-cell-1
Cheaper, but is that the same thing? An MJ1? It talks of up to 10A, but then says ‘The low continuous rating on this battery makes it NOT APPROPRIATE FOR USE IN HIGH DRAIN APPLICATIONS (e-cigs, vaporizers, or similar), but this is an exceptional 3500mAh cell that offers a solid 10A max continuous with 3500mah, and up to 15A manufacturer pulse rating. ’
At least for what little I know, the 10A, 15A it mentions doesn’t fit the ‘The MJ1 is a superior cell for the low-medium amp (10Amp), extremely high capacity battery packs, and applications. ’ description.
Do you / anyone here you know have a homebrew current tester? Pop a battery in, the circuit is just a low resistance resistor (in oil / heat sinked) to see what current you can get? What kind of resistor? from my ham radio studies eons ago, to get 5Amps with 3.7v, you need a 1.35 ohm resistor? 18.5 watts though. I might have 1/4w ones from radio shack from EONs ago!