Rechargeable Batteries for Fenix Pd32 and Zebralight h600

I recently purchased a Fenix PD32 flashlight and looking to also purchase a Zebralight H600 headlamp soon for use on things around the house (both will be EDC lights). I want to use 18650 rechargeable batteries on both lights, but which ones can I use? It seems that the Zebralight has a size limitation of 67 mm. Does the Fenix flashlight have the same size limitation?

With the 18650 batteries, I plan on buying a Nitecore i2 charger so that I can use it for other batteries if I decide to switch over to rechargeable AA, AAA, or C batteries later.

I have both of those lights and I'm using Eagtac 3400's Redilast 3400's, Redilast 3100's, and AW 2600's. All seem to work fine.

I have both of those lights and I'm currently using Eagletac 3400mAh batteries. Perfect in the PD32UE. Works in the H600w as well, but the spring is tight and really scratching up the bottom of the battery. Only appears to be cosmetic though. See my post here.

I believe these EagleTacs are some of the shortest protected batteries at 68mm, so I'm not sure if you can prevent this problem unless you get unprotected cells; maybe someone else can prove this wrong. I'm measuring an actual 68.072mm on some cheap calipers.