iPhone SE Battery
I thought it took a 000 as well. However, I tried both and realized the 00 works best.
I found out the battery tab screw holes are slightly misaligned by about 1/2 mm. This causes the battery to wedge in too tightly to the track pad which is directly above. Using a small drill bit I moved the holes slightly allowing the battery to move slightly toward the center of the laptop. This took the pressure off the track pad. Also I took the clear plastic covering off as well. It works great now.
I followed the instruction carefully and the battery works great. However, now my trackpad won't depress in all but the lower right corner. Anyone know how to fix this?