26650 Batteries

Garry: Believe me when I say I am no battery expert. I did some research on IMR (+ Chicago X taught me a thing or two) and INR and here's what I found out:

IMR is a misspelled acronym for LMR - Lithium Manganese Rechargeable. It is a safer chemistry than Lithium ion Cobalt, which is typical chemistry in most Li-ion cells. Safer because it doesn't vent or go nuclear or flame out. That is why most IMR(LMR) batteries are unprotected. Well that and because it costs money to add protection and IMR is not a big seller like Li-ion Cobalt.

INR is suspected to be Lithium Nickel Cobalt Aluminium Dioxide. Again, INR acronym should probably be LNR. That's all I know, but there is a Wiki article on it here: http://en.wikipedia.org/wiki/Nickel-lithium_battery Last entry was 15 months ago, so I suspect Panasonic has moved it out of the experimental stage. It is also supposed to be safer than Li-ion Cobalt and probably does not have protection built in due to cost. I think the Trustfire 26650 you saw is neither of these, rather it is a good old fashioned Li-ion Cobalt and should rightly have a protection circuit. Doesn't mean it actually works, mind you.

As Hikelite and mitro referred tohere and in another thread, unprotected cells should be ok to use in a flashlight that is regulated to warn you below a certain voltage level (usually 3a) by flashing or dropping to medium or low. My Balder BD-2, Uniquefire 3900 and I believe the JM07 all do this. When the light output dips or flashes, you know to either run in a low mode or replace the cell to prevent over-discharge.

BetweenRides, Thanks for the info! I have never tested "low voltage protection" in my lights (to even know which ones have it and what it's like to encounter it). What about charging? What if the charger decides not to stop at 4.2v? There's no protection circuit to kick in, so what will happen on one of these cells?

-Garry

The great advantage of the LiMn cells is low resistance, very little sag. If circuits are added then automatically resistance is added. Some 18650 from Sanyo are rated even for 20A discharge, the AW is rated at 16A discharge, hardly cheap mosfets can do such thing, and then as I mentioned resistance is added.

I wish I had seen those pics before now. I was never impressed with the design, but your photos lend an undeniable air of quality to this torch.

The milled trit slots look much better, for example, than in any mfr. pics out there...

Well done. As if I needed one more thing over which to obsess.

Low Voltage protection also works to identify sh!tty batteries. If I put Ultrafire 3000mAh batteries in my Balder, it starts blinking immediately and won't operate on high. Any good cell will operate the light just fine.

If you are using a good charger, LMR will charge like any other Li-ion cell, should stop at cell capacity around 4.17-4.20 (remember they are just another chemistry of Li-ion and have the same voltage operating range). I have two AW IMR 14500 cells and they perform on the charger like any other, come off at 4.18. If you buy the Xtar charger, you should be fine, but still follow the same prudent charging protocol and don't leave them alone, take off when the light turns green.

Or they could just go nukular on ya' ~~~ Wink

no kidding right - i saw those pics and started drooling

that n-light only says 18650's everywhere I look..where to get the 26650 version?

Sorry, pounder, we went off topic (as usual at BLF Laughing). If you re-read the OP, I ordered the ST60 (18650), it was out of stock and CNQG is sending me a JM07 (26650). The ST60 can run on 1 or 2 18650's only.

Simple test. Get yourself a current shunt rated to around 50A off eBay - like this one

http://www.ebay.co.uk/itm/50A-75mV-Current-Shunt-AMP-Meter-Gauge-/150592189350?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item230ffe73a6#ht_1091wt_1180

Read the instructions and attach it to your multimeter as suggested.

Short the cell across it and read off the current. If it can't do 10A on a dead short (Should be nearer 45) it is crap. You might be able to read a value before the protection circuit (if any) cuts in.

Whatever you do, don't run this test for any longer than it takes to read the meter.

Really, really don't do this for more than a second.

I disclaim all responsibility for melted shunts/meters/hands/houses.

thanks for clearing that up lol

We didn't go off-topic, we came back on-topic! See thread title!

-Garry

N.Shock provided a good link below that indicates at least one brand of "INR" branded cells are LiNiCoMn02 chemistry, like the Sony 26650VT cells. They're capable of VERY high discharge rate and are far safer than standard LiCo cells, but can still be volatile if there were a short or a puncture.

Personally, I completely avoid any cell not being explicitly represented as one of the safe chemistry formulas.

That's horrible advice. Even if someone was willing to ruin a SAFE battery with a dead short, which would, permanently increase the cell's internal resistance, what if it was not a safe chem or protected cell? LiCo cells DO vent flames and DO explode, and either/both can happen very quickly. Big cells like 26650's pack A LOT of power - pipe bomb power.

That shunt is meant for measuring voltage drop across it under load as a means to measure the current going across it, not to dead-short a battery, power supply, etc.

To answer question #2 on the first post the only ones are from manafont, they are only 4000 mAh + not the claimed 5000 mAh, but they should be close to the king kongs with mAh.

I have brought one of these just to test out and see if they can be used in series with TR-J12 with out modification unlike the king kongs.

TrustFire - Protected TF 26650 3.7V 5000mAh Rechargeable Li-ion Battery

#5 yes the TR-J12 will dim not sure about the others

Updated first post to include links to 26650 batteries. I'll keep track if anyone posts new ones.

Dave

Good work rides.

One thing i have not tested the trustfire 5000 mAh yet myself but reports on the net they are between 4200 and 4500 mAh like the king kongs, but i belive no one has been able to test both batteries with a discharge higher then 1 amp discharge due to basic hobby chargers and for the king kongs they have gone off data sheets.

Once my sample gets here most likely in 2 weeks i will discharge the trustfire 26650 and king kongs at 3 amps and then run a 7 amp discharge test with data logging and post up the graphs if hjk does not beat me to it, i think the trustfire protected 26650 is the safest option as its the only one protected and at 3 to 3.5 amp discharge the king kongs and protected trustfire 26650's should be close.

Im intrested to see if the protection pcb can give atlest 3.5 amps as thats all it needs to give and that is about the most your well driven xml will draw on one cell, since the 2400 / 3000 mAh 18650 trustfire flames can give 3 amps no problem i think they should be fine and early reports seams good.

There was a 1 amp test done here post #7

https://budgetlightforum.com/t/-/6606

SOLID bit of work Dave!! Heres 2 more for your consideration:

http://www.4sevens.com/product_info.php?cPath=53_57&products_id=2585

Of all these cells, which ones have the lowest internal resistance, and highest "C"?

thanks!!

Not sure about "all", but from those 2 you posted (4Sevens 26650 and Powerizer 26650), 2nd one is capable of higher currents and has lower internal resistance.

Updated first post. Thanks benckie and kramer!