http://www.doingoutdoor.com/2pcs-keeppower-18650-rechargeable-battery-2600mah-p-88.html
Official spec says 68.64mm for 2600mah, 69.08mm for 3100mah, 69.02 for 3400mah, none are likely to work!!!
-Jamie M.
Well that's a bummer. I really really hope there is some more tolerance in this light... the sc52 handles the longer 14500 keeppower batteries just fine, a tad tight, but ok.
All of my protected batteries are either the panasonics, or keeppower 3400mAh... really would be a shame not to be able to use them. Maybe an extra GTID oring would work as a spacer.
You canât use a spacer because of the tailcap design. The threads are anodized and the only part that makes electrical contact with the tailcap is the non anodized top of the body tube, makes contact with a copper ring inside the tail cap. It has to be screwed fully down or the light wonât work. You can disable the SC600MKII by unscrewing the tailcap only a 1/4 turn, so you can see how tight it has to be to make electrical contact.
I heard from an unofficial source that the recommended battery length for the SC600MKII is actually 67mm. 68mm is the absolute biggest battery you can fit allowing the tailcap to make proper electrical contact and without putting so much pressure to damage the electronics in the flashlight 
If you had the 2600âs you might just squeak it in, but I wouldnât even attempt the 3100âs or 3400âs for fear of damaging the light
-Jamie M.
When I ordered my SC52 I owned no 14500âs, so I got 2 ZL ones (rewrapped Sanyoâs?)
Now with the SC600 it seems I am going to have to buy some other type of small, protected battery for it, recommendations? Will ANY protected cells fit at 67mm or less?!
The zebralights are supposed to cut off at 2.7v, so I don't think using unprotected batteries would be an issue.
I'll definitely be careful trying out different batteries, not to damage anything inside.
i would definitely run my sc600 mk2 with unprotecteds 
no wasted energy from the PCB
Sounds like the unprotected NCRBâs in either button or flat is the best ammo for this torch
yep or simply rip out the PCB and metal strip
Do you have an pictures or instructions on doing this? I think people that get the MKII and have protected batteries will want to do this.
-Jamie M.
x2
I wouldnât do that tbh, you pay more for the PCM in the first place so it seems a bit of a waste to rip it off. You will also probably be left with sharp solder tabs on the top and bottom of the cellâŚ
As a last resort then I could see why you might want to do it but I would recommend just ordering a couple of unprotected cells from fasttech instead and using the protected ones in other lights.
I don't understand. Why would anyone "destroy" a good protected cell instead of buying an unprotected one?
Hi,
I agree with the above, but I just wanted to mention that one several batteries I had before, the wrappings got torn (these were 10440s in a different light), and I eventually ended up just removing the âlogoâ wrapping layer, and when I did, the strip going down the side, connecting the + to the PCB on the - end wasnât soldered at all, but only that outer wrapping was holding the strip to the + side and the PCB. I donât know how common that is, but wanted to mention it, because with that âdesignâ, thereâs no solder tabs involved. Basically it was just remove the outer wrapping and the metal strip fell off. There was also a much thicker wrapping UNDERNEATH all of that, which left me with a âblueâ unprotected battery. YMMV.
Jim
Iâve removed the protection on a few cells, simply because I had to in order to fit them in my light. Had I known they would not fit, I would have ordered unprotected.
On one other occasion, the only known good source was protected 26650, which I didnât need. I ordered them and removed the protection so it would fit the light.
If you have the option to order unprotected when you need it, go for that. Itâs easier, cheaper, and safer (the removal process includes a risk of shorting out the cell).
I have contemplated posting a How-To on protection PCB removal (I have the images already), but didnât bother as I figured there just wasnât anyone that wanted to do this.
why spend more buying an unprotected when you could simply âliberateâ the cell
protection PCB wastes a lot of energy, just compare the graphs from HKJ so for all my single cell lights i use unprotected. and for zebras itâs even better coz they have built in overdischarge protection
We now have Pangea Design's Pickpocket in stock! This titanium bottle opener can be used as a clip or keychain accessory. It also comes in a hex design for 1/4" wrenches or driver bits.
Howâs the MKIIâs comin?
-Jamie M.
We've emailed ZebraLight asking for an update and are waiting. The only reason we put up the pre-order is because we heard reports that other dealers were receiving their stock and estimated ours would be shipping/arriving this week. Keep in mind everyone is free to cancel their pre-order for a full refund.
No rush from me Looks like itâs amazing from those that have received theirs already! Hopefully ZL comes through soon for ya!
Not my pics:
-Jamie M.
Hi,
Iâll just leave my money where it is now, on the pre-order with you allâŚ