any visual cues that they might be fdk?
I went through my pile of used AAA cells and found these common characteristics of Japan made FDK cells:
1) the sleeve does not cover the transition from the body to the flat bottom. The transition is curved, not sharp
2) the sleeve is rolled anti-clockwise (right-hand rule direction)
3) all of them have “Made in Japan” written on them
4) all of them have the manufacturing date perforated in the sleeve reading from the + to the - pole
5) there are 4 visible vent holes in the metallic top button reaching above the plastic top cover. The top cover has no vent holes.
Powerowl 1000 passes 2 and fails 1, 3, 4, 5. It is not an FDK cell.
Cheers,
AA Cycler
Sorry to dredge up an old thread, but your post raises a question I have. I have many Eneloop (regular white 1900mAh) and equivalent “made in Japan” Amazon Basics NiMH. The Amazon ones were bought in 2018, before they switched to the current made in China versions. Both the Eneloops and Amazon Basics pass your tests 1-4, but fail #5. I cannot see any sort of vent holes anywhere on the metal button top on any of these cells. Perhaps that is no longer a feature of FDK-produced cells?