LI Ion Vs IMR ???????

Ok, I own and use sevreal LI-ion from AW and Redilast.

What exactly is the difference between Lithium Ion batteries and the IMR's
I see IMR's are generally lower capacity. But is there any reason to buy a few of these ?

The IMR types have a much lower internal resistance, so more juice will get to the LED/bulb under load.

The standard li-ion cells have a higher internal resistance, so less juice will get to the LED/bulb under load.

What light are you using them in?

Multiple XML-T6

Klarus XT-10
Klarus XT-2C
Klarus XT-20 (2x 18650)
O-light M21X
Eagle Tac M20C2 II
Sunway T-20C

I believe that with those lights you will be fine with standard li-co cells.

I don't know those models, but from a quick Google, it doesn't appear they are really stressing the cells.

Using the search function, we get:

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madecov said:

Ok, I own and use sevreal LI-ion from AW and Redilast.

What exactly is the difference between Lithium Ion batteries and the IMR's
I see IMR's are generally lower capacity. But is there any reason to buy a few of these ?

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The term Li-ion, is commonly (and incorrectly) associated with more common LiCo cells. Both are Li-ion cells. The difference between IMR and LiCo (ICR) cells is the chemistry of the cathode material. One uses Cobalt, one Manganese. These two chemistries are commonly abbreviated with the letters ICR and IMR. The 1st letter just means its a lithium ion cell, the 2nd letter stand for the cathode material, and the 3rd letter "R" just means its a round cell.

Generally IMR / LiMn cells are designed and used for higher current applications (aka power tools, ev's etc.) This is not always the case, however. There are some IMR cells with low 1 or 2C current ratings, just like LiCo cells. There are other differences in the chemistry, and IMR's are regarded as being safer, and in the CPF community they are usually used as bare cells. You still risk overcharging and overdischarging the cell however, just like a LiCo cell. But the results of short circuiting or overcharging the cell and something catastrophic happening with an IMR is less likely than with an ICR cell. Lastly, IMR's generally have a lot lower capacity when compared to LiCo (ICR) cells (20-50% lower, generally).

You can read up at batteryuniversity.com for more info.

For most people's use, a good set of protected LiCo (ICR) cells are all they need. But when you begin to push the boundaries of what a LiCo (ICR) cell can safely provide, is when you would need an IMR cell. Generally speaking, most "mass produced" lights are designed to safely run off LiCo cells. Some custom hotwire, and high current LED lights may require or recommend IMR cells.

Correct me if I am wrong. From what I have read the IMR's are safer to use in series. Is this because of a more consistent output? I just ordered 4 AW IMR's to use in series, little less runtime, more amps available in the short term.

Hello, I have the new Nitecore EA11 coming in the mail c/w a 14500 IMR cell. I also own (2) 14500 li-ion protected batteries with more mah (750 li-ion vs 600 imr). I believe it will be okay to use the li-ion 750 mah batteries but the performance will be slightly less then the imr cells. Is this correct? All batteries are made by Nitecore or branded that way. Thanks

Correct. But either way you should be fine. You should read Jasonck08's excellent post a few posts back comparing ICR and IMR types just to familiarize yourself with the differences which may not matter in your case.

For me, I don't mind the lower mAh rating of IMRs because I am happy to trade greater safety for capacity. The stabler IMR lithium manganese chemistry is less likely to go into thermal runaway. Hence IMRs are typically offered as non protected types.

I always pay for doubly protected mode types if it's available for a given size ICR if I'm using those, but I've been moving away from ICRs for awhile. I do have to use unprotected ICRs for small flashlights that use RCR2, 14520, 10180, etc. batteries since protected ones don't seem to be available in those sizes.

But getting back to your situation, none of that affects you and really which chemistry you choose is a matter of personal preference as long as you understand the capacity and safety trade offs.

My understanding of the advantages of using a 18650 IMR, over an ICR battery would be a) to better power a high-perfomance light that uses multiple 18650 batteries in series (and has high current draw), and b) to help avoid thermal runaway of a light that uses multiple 18650 batteries (strictly safety concerns).

I just picked up a Jetbeam WL-S4 (MT-G2) light and absolutely love it. I hoped that IMR batteries would be the best for this light, to get the most current to the LED (little, or no sag, and also best run times possible). Is this correct, or am I just better of using good ICR batteries?

I'm very diligent about how I match, charge/maintain my batteries (and the kinds of smart chargers I use on them), and I always use Panasonic-based batteries, purchased from reputable dealers, if it makes any difference.

Any help would be appreciated. Thanks, in advance!

david57strat said:

My understanding of the advantages of using a 18650 IMR, over an ICR battery would be a) to better power a high-perfomance light that uses multiple 18650 batteries in series (and has high current draw), and b) to help avoid thermal runaway of a light that uses multiple 18650 batteries (strictly safety concerns).

I just picked up a Jetbeam WL-S4 (MT-G2) light and absolutely love it. I hoped that IMR batteries would be the best for this light, to get the most current to the LED (little, or no sag, and also best run times possible). Is this correct, or am I just better of using good ICR batteries?

I'm very diligent about how I match, charge/maintain my batteries (and the kinds of smart chargers I use on them), and I always use Panasonic-based batteries, purchased from reputable dealers, if it makes any difference.

Any help would be appreciated. Thanks, in advance!

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ICR=highest capacity, decent current handling.

IMR=highest current handling, so-so capacity.

Hybrids=good current handling at ~10A, very good capacity.

To answer your question sufficiently, we'd need to know what current your MT-G2 is pulling at the tail, on high.

Chris

Hi David, I don't have that model but I have a couple of other JetBeam 18650 lights, and a couple of RCR123A lights and they were fine on ICRs, before I switched to IMRs for safety reasons. Since all these lights are regulated I'd say I noticed the shorter run time of the IMRs more than any brightness or voltage sag problems, but I'm okay to trade capacity for safety to some extent.

As far as I know - other than lower capacity - the only potential downside of an IMR is in use on a direct drive LED that cannot take as much as the cell is delivering. The Oveready "mini-turboheads" (M2-50, M2-XML) are this case.

Correct, if the LED can't handle it on direct drive, you could fry it.

Sometimes more heat sinking can help, etc.

nfetterly said:

As far as I know - other than lower capacity - the only potential downside of an IMR is in use on a direct drive LED that cannot take as much as the cell is delivering. The Oveready "mini-turboheads" (M2-50, M2-XML) are this case.

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Interesting. I didn't know that a battery would attempt to deliver more than the load by itself is trying to draw. Of course, the driver board requires some power, but not much. Is this issue because of the control circuit controlling the power?

magellan said:

Interesting. I didn't know that a battery would attempt to deliver more than the load by itself is trying to draw. Of course, the driver board requires some power, but not much. Is this issue because of the control circuit?

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My understanding is that direct drive is direct drive, no control circuit. But my background is process / chemical, not electrical.

Ahh. Yes, I think you're right about that, probably because of direct drive. Once I learned about DD I realized that most of my AAA lights, even the cheaper production models like my Olight i3S EOS, were running direct drive on the high setting, not just my Peak and TnC lights which are well known for that because of all the lumens they put out relative to their size. My TnC Micro Turbo and Extreme Micro lights, for example, put out 750 lumens using a CR2 size battery (actually an Efan IMR 15270) which is ridiculous.

LEDAdd1ct said:

The IMR types have a much lower internal resistance, so more juice will get to the LED/bulb under load.

The standard li-ion cells have a higher internal resistance, so less juice will get to the LED/bulb under load.

What light are you using them in?

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Hi
I have a solar rechargeable led fair lights and the specs says ICR, 14500, 400mah, 3.7V.
am not very technical and dont understand much on charging and dischrging
Need to know where to get these batteries from and what are the better options available if they are not ICR?
Lots of dodgy batteries on ebay and aliexpress. so if anyone has had experience with any of them, please advice link or site and alternative battery that maybe better
Thanks

It should also be kept in mind that almost nobody uses either ICR or IMR batteries these days. Pretty much ALL Li-Ion batteries in use these days are hybrid batteries of one form or another. The terms 'ICR' and 'IMR' are largely just names used to designate cells that are either high capacity or high draw, regardless of what the chemistry may be. But most all of these cells are hybrids of one sort or another. And as Li-Ion cells trend more and more toward cells with high capacity AND high draw, the line between 'IMR' and 'ICR' will continue to be blurred.

+1
Too add, buy from reputable sources............thats 1/2 the battle. Good brands, sony,samsung,LG,sany and panasonic which can be under a manufacturers wrap(keeppower,AW,efest,fenix etc etc etc).

So if not sure ask before buying, also what country to help others advise a place/shop. Unless you know the seller, ebay is not the best choice imo, nor aliexpress or other chinese supermarkets. Yes some are fine, others not so.

Very quick rough guide hsd......

3.6 or 3.7v is the nominal voltage, These cells are fully charged at 4.2v and can have a min discharge voltage of 2.5 or 2.8v depending from the manufacturer. Ideally top back off around 3.5-3.8v. If your going to use most of the cells capacity, try not to let them get bellow 3v. Usually by this time the light will warn you in one way or another, or simply not sustain higher modes(step down straight away or not enter higher modes).

Learn your light, check the voltage to build up a picture . If its used for 5m a day, might work well to top off once a week. If used for 50m a day, might be worth topping off every day..........what works for your use basically. A charger with a V readout is user friendly for ease, also no harm in having a multi meter(no need to spend and arm and a leg). This is a way to keep an eye on the charger and cell/s to work with, also useful to tell if there is anything untoward going on with either as well.

ven said:

+1
....
Learn your light, check the voltage to build up a picture . If its used for 5m a day, might work well to top off once a week. If used for 50m a day, might be worth topping off every day........

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Thank you for all the responses...
just to clarify
These are going into Solar rechargers, so I don't think I can monitor anything can I? They come out once a year. Do you reckon I should Recharge them more often to keep them going?
Can I Recharge these batteries in an electrical Recharger and see if they will work? Just on Case there is something wrong with the Solar panel itself?