I'm a battery NOOB!

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Davx
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I'm a battery NOOB!

Reading on this forum i learn a lot about emitter and circuit.. Now it's time for the lesson about battery...

Since now i use "standard" batteries like TF flames only because many people say that are good. Now i would try to inderstand.

There are many abbreviation like ICR, IMR, LiMn, LiPo4... and i know the meaning of only few of them. What they mean?

Why some kind of batteries are better than other in a flashlight?

The 18650 cell from a laptop battery can be used in a flashlight?

A 3-cell battery from a laptop that has 2200 mah indication has 3x2200mah 18650 in it?

Ok.. I think i ask everything that is not so clear for me. I hope someone would have the time and the patience to answer me or simply to give a link where i can find all this info. (i found some info on flashlight wiki but not everything).

"There are always new jobs, women, and apartments......there is only ONE BLF." - Chicago X (27/03/2012)

devman
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Joined: 04/27/2011 - 06:24
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Location: Hong Kong / Vancouver, Canada

Davx wrote:

Reading on this forum i learn a lot about emitter and circuit.. Now it's time for the lesson about battery...

Since now i use "standard" batteries like TF flames only because many people say that are good. Now i would try to inderstand.

There are many abbreviation like ICR, IMR, LiMn, LiPo4... and i know the meaning of only few of them. What they mean?

Sorry, but the best place is actually the wiki.  Most batteries you'll encounter right now are lithium-ion (lithium cobalt).  Mass market, cheap, good power density.  LiFePO4 batteries are becoming more available, and are much less dangerous, but you lost about 20% of your capacity and get a lower voltage compared to lithium-ion.  They're harder to get and (for me, at least) more expensive.

TR, ICR, IMR, IFR are shorthand codes written on batteries to tell you what chemistry they use. (TRaditional and ICR are both lithium cobalt, IMR is lithium-manganese, IFR is LiFePO4)

LSD is the only acronym that isn't a battery chemistry, and stands for Low Self Discharge, meaning you can leave it unused for long periods of time without the battery running flat.

Davx wrote:

Why some kind of batteries are better than other in a flashlight?

When your battery doesn't match the requirements of your emitter, you require hardware to try to make up the difference.  Buck/Boost circuits raise or lower the voltages to match the voltage requirements of the LED, for instance.  Losing, say, 15% of your energy in the driver circuit is pretty common.  Some battery types just won't deliver the current wanted.  etc.  Sometimes you pick a battery based on other criteria, such as lifetime (eg. the IRF batteries have a longer design lifetime, so are more suitable if you're going to seal the device and can't replace parts), discharge rates, safety concerns, operating temperatures, etc.

Davx wrote:

The 18650 cell from a laptop battery can be used in a flashlight?

You _can_ use 18650 cells from a laptop battery, but it can be messy, and until you've been around them a bit more, I wouldn't.  Batteries from packs are usually different as they have tabs in place of the usual nipple/flat end, and are soldered together, making it very easy to insert them backwards.  Add the lack of protection circuitry on the cells and you've got something you don't want to play with.

Davx wrote:

A 3-cell battery from a laptop that has 2200 mah indication has 3x2200mah 18650 in it?

Yes.  If you look at the pack, you'll see that it's rated for 10-12v.  Thus, 3 cells in series (3 x 3.7) are needed.

Whew!  Thanks for letting me exercise my occasional need to be pedantic!

Davx
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Thanks DEVMAN!  I really appreciate "pedantic" explanation!

"There are always new jobs, women, and apartments......there is only ONE BLF." - Chicago X (27/03/2012)