IMR Batteries..Explain?
- Thread starter DavidRZ
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ChrisGarrett
Flashlight Enthusiast
Hello and welcome.
This particular forum is full of info about the cells and batteries that we commonly use in flashlights, power banks and whatnot. It's best if you read up a little bit before playing with this stuff, because houses do get burned down to the ground!
You'll frequently come across some odd, but now somewhat archaic abbreviations such as ICR, IMR and IFR. I=lithium, C=cobalt, M=manganese and F=iron, R=round cylindrical cell.
They denote three different cell chemistries all having differing strengths and weaknesses. Lithium-cobalt is now somewhat scarcer, but it offered a bit more capacity, at the expense of current handling. Lithium-manganese, was kind of the opposite--higher current handling, but lower capacity. Both are 3.6v/3.7v cells that charge up to 4.20v off the charger. Lithium-iron phosphate has a nominal voltage of 3.0v/3.2v and charges up to ~3.6v, so you see a difference right there.
The RC guys like to use the IFR chemistry, since it's a bit safer and can take a lot of abuse. Power tool makers like the IMR chemistry, because it can deliver more power to a high torque motor, at the expense of runtime. Everybody else will use the ICR cobalt chemistry.
Anything can get hot enough and vent and cobalt likes to vent with flame, so when you see some guy on Idiot Tube, torching himself with his E-Cig, he's probably using a crappy cobalt cell that's gotten too hot for whatever reason.
Nowadays, we've moved into hybrid chemistries and so those three descriptors aren't all that accurate when discussing stuff in 2018. IMR is still used to denote high drain capable cells, although there might not be all that much manganese in the cell itself.
Chris
ChrisGarrett
Flashlight Enthusiast
Always match the cell/battery to the load that it's going to see...ergo, if a light is a high drain, high current light, like my Emisar D4, I need to feed it a cell that can handle up to 15A-20A, such as the Sony VTC-5A (or others) or my Aspire 18350, if I'm running the 18350 body that I bought for the light.
Now, if I'm running my Jose Vanilla Convoy M2 with XM-L emitter, which doesn't go above say 3A, then a regular old Panasonic NCR18650B cell will be more than sufficient.
You really need to know what a particular light sucks down, juice wise, on high/turbo, to have a clue as to what cell to use.
Here's HKJ's site and you can click on the family of cells/batteries and look at his tests and graphs.
Memorize it, breath it, practice it and live it.
http://www.lygte-info.dk/info/indexBatteriesAndChargers UK.html
Chris
