First off - this is basically some early thought for some custom work I may want done in the future. But the questions are specifically about electronics, and the theoretical & practical matters of cells/batteries, so I believe this belongs here. If it doesn't, moving it certainly won't offend…
I have recently had a few thoughts swimming around in my head, all of which are somehow related to small cells. The basic question is how hard small cells can be pushed. If I have someone make me a cell holder for a CR2 to fit a CR123A light, or a 2xCR2 to fit a 2xCR123A light, will a light made for the larger battery be drawing dangerous amounts of current from the smaller battery?
My core reasoning is that I don't care much about runtime. Right now I have CR123A lights and CR2 lights. Which means I have CR123A cells and CR2 cells. I have two separate thoughts. First is that if I wish to use a CR123A light, and am somehow (gasp!) out of cells, I could theoretically fall back onto using a spacer/holder, and pop in a CR2 cell. I know people use spacers w/ LiIons, what I don't know is how much smaller you can safely go, and if this applies across LiIon and primaries…*My 2nd thought is that I don't have any 2xCR123A lights, partly because I have yet to really 'need' one, partly because of the whole unbalanced-cell-reverse-charge-poof issue. So thought two goes along the lines of, could a 2xCR2 holder be fabricated to fit 2xCR123A lights that would also offer extra protection - either through a diode to prevent reverse charge or, I honestly don't know what. I was going to go to school for electrical engineering but the school I was attending at the time dropped the major. I haven't done much electrical work as a hobby in quite a while either, so my thinking is rusty. But the point still stands - will a light designed for a pair of CR123A cells draw too much current from a pair of CR2s?
Third (and final, I swear) point is something like - I would like to have a tiny little light custom built for me at some point in the future. A lot of the very small lights power 5mm LEDs. Now, I have heard it said around here that a 5mm LED is far less efficient than a power LED being underdriven for the same output. So, do we stick to 5mms because of the need for optics/reflector, or does it have to do with running off of 1.5v button cells or what have you? So the third point is basically, let's assume a CR1-3N cell powering my hypothetical little light. These are like 160mAh cells, so I assume they can't be driven nearly as hard as a CR2. But could a reasonable med/low be obtained safely? How high could one safely push it, albeit killing any notion of runtime in the process…?
These are all just curiosities at the moment, but the thoughts have been bugging me, and I was hoping someone might be willing to share any insight - thanks in advance…!
Brian
I have recently had a few thoughts swimming around in my head, all of which are somehow related to small cells. The basic question is how hard small cells can be pushed. If I have someone make me a cell holder for a CR2 to fit a CR123A light, or a 2xCR2 to fit a 2xCR123A light, will a light made for the larger battery be drawing dangerous amounts of current from the smaller battery?
My core reasoning is that I don't care much about runtime. Right now I have CR123A lights and CR2 lights. Which means I have CR123A cells and CR2 cells. I have two separate thoughts. First is that if I wish to use a CR123A light, and am somehow (gasp!) out of cells, I could theoretically fall back onto using a spacer/holder, and pop in a CR2 cell. I know people use spacers w/ LiIons, what I don't know is how much smaller you can safely go, and if this applies across LiIon and primaries…*My 2nd thought is that I don't have any 2xCR123A lights, partly because I have yet to really 'need' one, partly because of the whole unbalanced-cell-reverse-charge-poof issue. So thought two goes along the lines of, could a 2xCR2 holder be fabricated to fit 2xCR123A lights that would also offer extra protection - either through a diode to prevent reverse charge or, I honestly don't know what. I was going to go to school for electrical engineering but the school I was attending at the time dropped the major. I haven't done much electrical work as a hobby in quite a while either, so my thinking is rusty. But the point still stands - will a light designed for a pair of CR123A cells draw too much current from a pair of CR2s?
Third (and final, I swear) point is something like - I would like to have a tiny little light custom built for me at some point in the future. A lot of the very small lights power 5mm LEDs. Now, I have heard it said around here that a 5mm LED is far less efficient than a power LED being underdriven for the same output. So, do we stick to 5mms because of the need for optics/reflector, or does it have to do with running off of 1.5v button cells or what have you? So the third point is basically, let's assume a CR1-3N cell powering my hypothetical little light. These are like 160mAh cells, so I assume they can't be driven nearly as hard as a CR2. But could a reasonable med/low be obtained safely? How high could one safely push it, albeit killing any notion of runtime in the process…?
These are all just curiosities at the moment, but the thoughts have been bugging me, and I was hoping someone might be willing to share any insight - thanks in advance…!
Brian
