Li-ion vs IMR

[candlelight001]

Checked back into the battery world recently and noticed that there's IMR (lithium manganese) batts out there now. How do they stack up against the older protected li-ions? When would you use one over the other. Somewhat interested in the science, but more interested in the on the ground impact. If this has already been covered feel free to refer me to a link, my search came up dry. Many thanks!

 

[Tally-ho]

http://www.google.com/search?q=imr+cell&sitesearch=candlepowerforums.com

 

[ateallthepies]

From my own searchings I found that our regular rechargeable lithiums we use (AW, Pila etc...) have a max C rating of 2 which means they can be safely depleted in a maximum of 30 minutes.

IMR have a much higher C rating but have lower capacity and are better for high drain lights above 2 C.


You need to find the current a light uses then decide on the battery chemistry and capacity to most safely run it.


Steve.

 

[45/70]

candlelight, just as info, IMR (lithium manganese oxide, or LiMn) and the older cells you refer to, which are ICR , or more commonly called "LiCo" (lithium cobalt oxide) cells, are both "Li-Ion" cells. There is a third type of "Li-Ion" cell referred to here on the forums also, IFR, or more commonly called "LiFe", or LiFePO4 (lithium iron phosphate). These are all "Li-Ion" chemistry cells.

A fourth common "Li-Ion" chemistry that is used widely in the R/C world and some consumer electronics, such as cell phones and small PDA's etc, but not much in flashlights, is "LiPo", or lithium polymer, which is a form of "LiCo" chemistry that utilizes an electrolyte that is in a "polymer" form, rather than a liquid. There are also several other "Li-Ion" chemistries, as well.

LuxLuthor did a writeup a while back that explained some of the different characteristics of the various chemistries of Li-Ion cells we use here. You may want to give it a look. Also, Battery University is a commonly referred source of information about many types of battery chemistries, and their general characteristics.

Dave

 

[candlelight001]

Hey folks, thanks for the references and the explanations, much appreciated. I'm struggling a bit w/ the technical side of this. Wondering if someone more expert could break down the pros and cons of the older lithium cobalt vs the newer lithium manganese for the following applications:

1) Ra Clicky
2) Zebralight H31
3) Malkoff M60L in a G2 body
4) Lumens Factory EO-9 or HO-9 in a G3 body

Many thanks!

 

[ateallthepies]

I'm no expert but if a light draws more than about 4 amps with 2600 mAh 18650's then switch to an IMR.

With 16340's at 750 mAh then a current draw over about 1.4 amps would need IMR cells.

So you need to know the current draw of each of these lights and the capacity of your batteries to work out what is safe.

Anyone feel free to correct me if i'm wrong?

ATB,

Steve.

 

[candlelight001]

So you need to know the current draw of each of these lights and the capacity of your batteries to work out what is safe.

Steve.

Forgive my ignorance, but I'm not sure how to do either of those things. Anyone have a sense of which battery would be best match for the lights listed? Many thanks!

 

[psychbeat]

Unless yer running a DD light or high power incan

IMR seems like overkill + u take a hit in capacity.

the lights mentioned wouldnt benefit IMO from IMR over
"standard" rechargeable lithiums.

 

[tre]

Here is you answer in English.

(LiMn) IMR cells are safer than LiCo
IMR cells will give you less run time

LiCo cells give you more run time but are not as safe (hence the need for
a protection circuit).

These are the only things that you will notice in the first 3 lights you are talking about (I don't know anything about the Lumens Factory light).

Most people use IMR cells because they can handle higher amperage loads where LiCo cells top out at around 5 amps (a bit more or less depending on the actual cell). In a high amperage direct drive light you may need to use IMR because a LiCo will go :poof:

I like IMR cells for their added safety (at the expense of run time)