MrGman post shows, to me, a good reason for use of unprotected LiIon's, and monitoring them closely particularly when run in series. Most of the protocol for cell maintenance that MrGman mentions is being used for NiCd and NiMh cells which have never been protected, and these same safe guards can be used for LiIon's too, ideally unprotected LiIon's. I mostly use unprotected LiIon's particularly for high drain applications due to their usually higher capacity. I know they don't have a so called protection circuit, so do not depend on it, and monitor them throughout their life for signs of reduced capacity, also checking voltage in high drain applications to see if they are discharging at the same rate. Making sure they they are charged up to the same voltage is important too, a good time to notice if a cell is suddenly not taking a good charge, a possible sign of a damaged cell. At first signs of dimming in an incan light I switch them out. I keep them in pairs, or threes, depending on the voltage required for a given light, and number them. For use in constant current lights, particularly buck constant current lights I pay particular attention to the cells. Most of my boost constant current lights will dim before a cell gets to far below 3 volts under load.
It sounds like a lot of work, but is actually part of the enjoyment of being a flashaholic, and working with batteries, lights, circuits, etc.
Bill
The nickel cads and metal hydrides are much less likely to catch fire if they get a real reverse charge. I have seen many a nicad reverse charged in multiple battery stacks. I don't even care about what happens to NiMH. The cell may get ruined but I have never seen one or heard of one burning up or exploding. This is a much more real possibility with Lithium Ion batteries which is why they put in the cut out circuits.
So basically Bullzeyebill, what you are saying is that, we should take a simple 1 button operational device, that although it is a great tool, a fun tool, we should turn it from something very simple to operate and easy to maintain, into something very tedious and time consuming to maintain, elevate it into an ongoing science project with potential consequences of fire or explosion, for the sake of having more fun with it?
I am not going to say you are crazy or whacked or loco, or anything like that.
, I am just going to say you got way too much time on your hands.
As for those of us who simply want the light to work when we turn it on and run for a reasonable runtime, with minimal maintenance, use primaries, or top off your rechargeables, or use the type that only use one battery.
As all these hot new mega LED flashlights start drawing power on par with a low efficiency krypton lamp (but fortunately putting out the light of a small sun), this is going to make all your rechargeable batteries appear to be crapzapier and less consistent. High constant current circuits are the fastest and easiest way to find the weakest cell in a battery stack and drop it out. The only thing missing to make it a bona fide test circuit would be individual voltage meters across each cell to see what the voltage the cells are at and you could start matching them up right there.
Maybe this would be a great opportunity for someone to start selling matched batteries, in pairs, groups of 3, 4, sets of 6. Tested and proven to have the same ampere hour rating within 2% or better, and same voltage drop within 2% or better. :candle::candle:
But then again, I wouldn't be willing to pay the extra costs to have them.
