I've looked around this sight. I've googled it. I still don't know what IMR batteries are. I checked acronym_finder.com. What are they and what does it stand for? Sorry for the silly question. I don't want to fill up this great sight with stupid questions.
They are lithium manganese cells. The AW brand sells a line of them called IMR, but they are really LiMn.
They allow much larger current loads.
Oh yes, I was going to use Lithium Manganese for a 23' solar-electric(and possibly hydrogen fuel cell) boat for my senior project. (4) 25.9V 104AH packs. The mfr wouldn't give me charging info so I went old fashioned with AGM.
Thanks guys, I hate feeling left in the dark.
High school senior project? Cool. LiMn is also much safer (look at the max charge rates!)
Electroman187, I'm glad you brought this up.
IMR apparently was a typo which became permanent... hence why you won't find an acronym for it. My guess it was Chinese confusion of lower-case versus upper-case Latin letters.
The proper acronym would be LMR, standing for, and let me shout this:
Lithium Manganese Rechargeable
Comes from confusion of people writing "lmr" in lower case, then being accidentally written as to "IMR" in upper case, which looks similar if using a font with no... ah, I forget the term for those little 'feet' for Latin characters... someone help me out.
Perhaps to the annoyance of some, I've started a one-man crusade to make "LMR" replace the incorrect term "IMR" (which would be "imr" in lower case), but that typo'd acronym is so ubiquitous that it's even inkjet-stamped on battery wrappers themselves. So, others to avoid stepping into that fray, as you can see above, simply write "LiMn" or Lithium Manganese. I've seen more commonly writing LiMn in product descriptions now, next to "IMR", to attract more keyword searches. However, doing a search of "LMR" combined with "lithium mangense" on an internet search site, literally only my posts and a post from a guy on an e-cigarettes forum shows up, at this point (hopefully that'll change).
AW is not the only marketer or brand of LMR batteries. Lighthound sells a LiMn 14500 by "BDL" brand, but unfortunately you have to use the search term "imr" to find it, while using "LiMn" WILL bring up AW's LMR batteries. Good price too. Interestingly, AW is also now making LiMn cells in 18350 size (half of an 18650, for people who want multi-cell voltage but don't want the bad runtime of 2 16340's), something he originally said he wasn't going to do, thinking there wasn't enough demand. Kind of wish I'd known before I picked up my Ultrafire 18350's.
http://www.lighthound.com/IMR-14500-Rechargeable-Lithium-Battery_p_3602.html
Other non-AW brands are available in searches, and I think Ebay.
LiMn can produce higher current than Lithium Cobalt (traditional lithium ion), but has less runtime. They are safer than LiCo cells in that they're not as likely to explode or vent hot gases, and hence don't come with protection circuits. LiFePO4 is probably a safer chemistry, and is generally cheaper, usually a lot cheaper, but LiMn charges up to almost what a traditional Li-Ion cell does, whereas Lithium Iron only charges to 3.6 to 3.8 volts.
LiMn is usually used by people who need high current delivery relative to their battery size (like in the old days, running a Cree MC-E in a keychain flashlight with a 16340). People who push the limit with high-current flashlights and high power modifications often prefer BOTH a safer battery AND a capability to deliver high current, more than runtime. Because, the bigger the battery, the bigger the boom, or the more likely it will go boom if you screw up. For instance, a "C" size li-ion battery scares me a lot more than a 16340. I'd rather push a 16340 (CR123 size) battery too hard than a 26500. NiMh is also a safer chemistry, but only produces 1.2 volts. So you see big Mag Lite modifiers using those in series.
Than what does ICR, or NCR? How about CGR? Thought so. :) AW's IMR cells are known for their superior discharge abilities vs their competitors-look at the 14500 on Lighthound. Its also pretty damn hard to overload a 26500.
The "LMR" versus "IMR" question reminds me of a conundrum I've encountered in religion. What happens when a doctrinal error, or spurious addition, becomes official and de rigeur? What is the true dogma then, for the adherents who consider official church policy and interpretation to be authoritative, yet when the scriptural source contradicts it? Such as, in Islam, when the penalty for speaking ill of Muhammed is death (I believe by beheading), yet a Mosque leader tells his followers that their religion is peaceful and non-violent? This is a question many Muslims are faced with today: follow one's scriptures orthodoxically, or follow a new traditionalism which leaves violent penalties behind, like has occurred in all of Judaism? What about Christians who say men should not have long hair, yet their own icons of Jesus is represented with long locks, with historical evidence supporting the same? What happens when the real acronym is so unused as to become useless and unrecognized, and the incorrect acronym is unversally used--which acronym is "correct" at that point?
Please don't quote full posts when replying... especially mine, since I'm verbose.
I don't get your witty point on ICR or NCR. Those are brand model designations. It's like asking what does Hyundai's XG350 model stand for? IMR is an (incorrectly-written) industry standard designation, whereas ICR and NCR are not, being trade designations, or product series, by unique manufacturers. With Panasonic (who, for those who don't know as much as srfreddy), uses the designation NCR as a prefix in their rechargeable battery brand line, I believe they are adding Nickel to their lithium cobalt chemistry in a special, probably patented process. With ICR (which I believe is Sanyo's brand model prefix), why don't you do the research and get back to us? Perhaps it stands for iithium Colbalt Rechargeable, because some people don't know the difference between i and L? So if you're going to start saying there's no significant difference between i and L, or lithium is the same as "iithium", go head, have fun, you'll have an uphill battle.
It's also not clear what you mean by how hard it is to overload a 26650. There are plenty of modders on CPF who could overload a 26650, but that wasn't what I had in mind when I said "in case you screw up" (or your equipment fails). What I had in mind was a short-circuit, or even a partial short, in which case, it's easy for any battery to become overloaded.
I also find it humorous that your opinion that BDR's 14500 LiMn's are crap batteries, to somehow negate my point that there are other marketers of Lithium Manganese Rechargeable batteries out there. I think you need a course in logic--or, if that's not what you meant, contradict people more clearly, and offer evidence of your correctness.
ICR is a generic term that I've seen sellers use for generic 18650s.....
What are people using to charge LiMn batteries? I have the cheapo "Digital" dual bay 18650 charger from DX that I use with li-ions. Will that work? I'm thinking about getting some LiMn batteries for my XM-L lights, though I'm pretty happy with the output of my Trustfires.
I use a 4sevens charger, plugged into USB until the recall replacements get around. (Unsafe for low capacity LiCo on AC power)
It is LCR, Lithium Cobalt Rechargeable. If someone writes it as an i, it's a typo, even if that typo were to be universal. Even to native speakers of latin-based languages, it can be hard to tell the difference between an upper-case i and L. (When I was a kid, I was in disbelief that Sports Illustrated would choose the font they did for their magazine--it looked like 3 lower-cased L's in a row: "lllustrated".) Update: BLF's font, when you're composing, puts a serif on the I, while in the "read mode", the I is is sans-serif (see next post).
Chinese apparently have a penchant for following convention, and I think they care not what they're called or written as as long as people find and buy them, nor are they renowned for their great English writing. (I posted a humorous example of Chinglish from Kaidomain earlier tonight: Deep Mental Reflector.) So if they give Lithium Cobalt Rechargeable the same treatment they do to Lithium Manganese Rechargeable, by mis-capitalizing an i instead of an l, so be it. But it is not iithium cobalt rechargeable. I just find it humorous that the typo gets re-adopted back into Latin-based languages, and even to most native speakers, it goes over their heads. Even more humorous is how then some people will then fight for the typo, or refuse to admit it's a typo. Goes back to my question of 'what is true orthodoxy when the universally-held belief is based in error'. What is correct: IMR or LMR, when literally no one but me and some accidental guy on the entire internet, write it properly? You'll have to decide for yourself. Again, some just avoid the mess and maintain literal accuracy by calling it LiMn (which will hopefully overtake the term "IMR"). Some like me may use LMR to simply use the term correctly, in addition to raise peoples' consciousness (this strikes at a human trait deepr than just battery chemistry). And some, like you, will maintain that IMR is literally correct, even if they can't come up with a defition of what it stands for. For some people, apparently yourself included, just the fact that it's conventional makes it accurate and proper. Like when people mispronounce "colonel" as "kernel", "chitterlins" as "chit'lins" or "cursing" as "cussing", or "soldering" as "soddering". And, there is something to be said for that. After all, what is "correct" in English (not necessarily in other languages) is often defined as what's most-commonly done. English wasn't even really considered a proper language until a few hundred years ago, being seen as a pidgin-like kluge of other languages, and I get a sense was looked-down upon as at least somewhat rude by even the English themselves long ago, at least when they were ruled by the French. But then again, sometimes a typo is just a typo, even if universal. The terms Lithium Manganese Rechargeable and Lithium Cobalt Rechargeable are new enough that I can stake that point. And I will not let my own personal writing style be prescribed by Chinglish nor Engrish. (BLF appreciation moment: that last sentence probably would've been censored by DM51 on CPF as "abusive" or "hateful", even though it is not).
brted, AW states that any decent, standard li-ion charger will work for LiMn, but that due to its lower internal resistance, chargers tend to overcharge them, and that it varies by charger. To my knowledge, there is no special LMR charger in existence. LiMn is considered fully charged slightly below where LiCo is generally considered fully charged, despite chargers' tendency to overcharge them. AW has more information on his CPFmarketplace as to which specific voltages are okay and not okay.
Okay, I got the answer. Those little bars on the top and bottom of letters in some Laton fonts, and not others, are called serifs.
Fonts with those little bars serifs are called serif fonts. Fonts without them are called "sans serif".
The problem apparently came about from people using primarily lower case in this internet age, abbreviating the long-form term "lithium manganese rechargeable" as "lmr", but then non-English experts running industrial printing machinery (for cell wrappers) switching to capitalization. Either they used a sans-serif font, where it would've been impossible to discern between "i" and "L", or they used a serif font and mistakenly put an "i" in there.
Hence why I prefer serif fonts, and why I intentionally include serifs when I handwrite the letters i, L, and the number 1. It disambiguates i's and L's, which is the source of much confusion in communities which rely on rechargeable lithium cells (laser fora, e-cigarettes, and most of all flashlight fora), coming to a head in this thread. AND, as far as I can tell (if Google is any guide), this is the first time the subject has been truly hashed out on the internet. So, you guys are part of history in a way. Sans-serif fonts cause their biggest problems in acronyms, where the correct letter usually cannot be discerned by context.
To many, a sans-serif capital I is first recognized as a lower-case L. I also think of times when lack of serif makes reading more difficult, such as the brand name Mitchell1 (online automobile repair manual company). I wonder what kind of marketing idiot came up with that as the name of the company, and what ignorant CEO passed off on that, not thinking the name might get published or confused as "Mitchelll", as they do have international customers, and not everyone is going to make write its number "1" in yellow like they do.
Personally, I won't let lack of serif, or Chinglish typos dumb me down. Even if that makes me unusual, or even unique.
That was a couple of well thought out posts, brjones... nothing I can add to that.
brted: For what it's worth, I've been charging my LMR cells using the same charger I use for the rest of my lithiums. As of 3/19/2011 my house is still standing 
Thanks, Match <natch>.
Yep, chargers' tendency to overcharge them is not a safety hazard as far as I know, but AW does point to the possibility of their useful lifetime being reduced (internal wear or damage). Normally at this point I'd go the distance to fish out AW's latest CPFM thread and post it for the convenience of readers, but I'm so not loving CPF these days... and how it's so hard to find AW's current thread because they keep ending them and beginning new ones. Sorry for being inconsiderate... gotta tend to my life at the moment, but people can search 'AW batteries' at cpfmarketplace.com. One thing I did notice is that CPF's marketplace site never seems to go down ($$). Lighthound sells AW batteries at slightly higher prices, but someone's already making an order and doesn't need many, you might save money by avoiding AW's shipping and insurance costs. With AW, it seems you're pretty much guaranteed to get a good product (if pricey), but that doesn't mean he's the be-all and end-all of batteries either. There is life outside of CPFMarketplace.
No, it's college. It is not a group project. I am working with a local boat builder. The batteries are made by a German company and they are $2500 a piece 
But we decided against them because they wanted us to use their AC-powered charger. I needed to charge them with a MPPT solar charge controller.
Had to look that acronym up. AGM: Absorbed Glass Mat batteries (lead acid).
Yeah, lead=heavy=not ideal for boats.
Sounds probably too late at this point, but since you obviously are still doing research, there are crazy cheap LiFePO4 18650 batteries being sold on Ebay right now from a Chinese seller. $2 each, with free shipping. I ordered some, but they haven't arrived yet so I have no opinion. And might take too long to arrive in time for your project. But wondering if you considered Lithium Iron before committing, and if so what were your pros/cons, and why not ultimately?
I think LiFePO4 are being used in mobility devices like electric scooters now, assumedly because they're safer while still having a good energy density and ability to dump energy pretty quickly--and of course lighter than lead-acid. If those Ebay ones are good, seems like a good way to build a cost-effective and not totally-scary battery pack. I also wonder if a 'shipload' (sorry) of cheapo NiMH AA's in smaller serial packs, joined to larger parallel packs, might be the cheapest non-lead acid option. Those are some serious battery needs you got there. I hope you let us know how it works out. Lithium Manganese sounds like one of the most expensive ways to go, although perhaps the best from a qualitative point of view, including safety but not cost as a factor (not sure).
brjones, thank you for all your insight on LMR batteries. I think you have explained why there is a lack of data on the internet. I think people would be really surprised how many errors have been passed through history. Have you studied calligraphy or something? Everything you said makes sense to me.
As for the batteries, since this is a one person project with a lot more considerations than just batteries, the scope of the project was to spec and use off-the-shelf parts. I didn't want to get into assembling batteries. The lead-acid batteries are cheap(8*$200) and have been a standard in the boating industry for decades. And since it's already the standard, there's more charging options, not to mention USCG approval. Try to find one shore power marine-duty charger for any lithium chemistry battery. Then try to find a solar charge controller that can safely charge lithium chemistries and get the manufacturer's approval. If this were a group project, then it would probably be a different story.
Speaking of common errors widely accepted don't forget that, 18650, 14500 and similar aren't 'batteries' , those are cells