finally got the 3100 callie's kustom today. yep, the battery was quite big compare to my AW 2900. it's about the same size and length as the eagletac 2400 batteries but anyways i had to remove the label in order to fit it in the TK11 but still a tight fit. can't wait to test these batteries out for myself after it fully charges. oh yeah... it's too bad these batteries won't work in my eagletac t20c2. wonder why.. the top isn't all that flat either..
At least you were able to get them all to fit in your TK11. 
As you know, one of mine (eX-cell branded version of the same battery) was just a little *too* wide, and wouldn't go in no matter what.
Trick with the flat tops is to use a small neo magnet, i do this with my unprotected cells.
PLEASE be careful putting the magnet on the positive (+) side. A good lateral bump can cause a dangerous short.
Oh i am careful indeed and the neo magnets are small and strong, i will post a pic when i can.
I wonder how much the resistance of a cell would be raised if you were to use electrically conductive thermal paste or even solder (if practical) to affix the magnet on the nipple end, thus giving at least a little more peace of mind when using your lights... I may have to try that... I also wonder if using magnet-extended cells would mess with lights that use a magnetic control ring....?
I have seen people place a mound of solder on the end of their battery, and eliminate the magnet altogether. All depends if you are comfortable with soldering on to a li-ion cell.
And yet, XTAR 2600 is hard to beat....and cheaper.
SO...prove me wrong.
Better than Sanyo.....with better board, connection and wrap?
They have higher capacity, 3100 vs 2600.
And under the Callie's brand wrapper, you find a genuine Panasonic cell.
OK, whether you prefer Sanyo or Panasonic is like asking whether you prefer apples or oranges - they are both big, trust worthy brands, and it's personal preference at the end of the day. The point is though that you are getting a high capacity, name brand cell with the Callie battery, just as you are getting a name brand cell with the 2600mAh Xtar.
Sanyo is a subsidiary of Panasonic... Panasonic bought the controlling share of the company in 2009...
Their cells are now likely produced in the same plants...
The Callies Kustoms are also wrapped AND taped https://budgetlightforum.com/t/-/2054
https://budgetlightforum.com/t/-/3653
The 3100's will put out near stated capacity at 5A discharges. In my testing the X-tar protection trips at 5A. I have not opened up an X-tar to see what the PCB is ill let someone else do it. I have wasted too much money already opening cells up :)
This is where they really "shine" 140 min use vs 90. https://budgetlightforum.com/t/-/2785 "Who would benefit from a CK 18650 , well just about anyone , but I can see a real purpose for this battery with anyone requiring light for as long as possible , Police , Search and Rescue , Med Techs , etc . When lives are on the line those 30 or more extra minutes of run time , could be the difference in some ones life . Who said ? what is your life worth ? "
They seam to be getting great reviews so i'll most likely pick one up after I recover from purchasing a Xtar WP2 II. I have a couple of the cheap chinese "digital chargers" and TF flames but did not want to take the risk of destroying a good 18650
Doh!
Yes, this is true - I'd forgotten that. Makes the Sanyo/Panasonic choice a moot point.
[quote=Stephen Wallace]
Doh!
Yes, this is true - I'd forgotten that. Makes the Sanyo/Panasonic choice a moot point.
[/quote
Except, no one wants to mention the cost...
Xtar is more "miles per gallon"