Even with NiCads memory effect was largely unseen. It only occurred when you had chargers that kept the charge maintained over a very fixed range. More people have destroyed nicads trying to avoid or "remedy" the perceived memory effect than actually ever experienced it.With old NiCads you had to worry about memory in the cells. With new LiPos you never discharge fully. You don’t store them at full charge, but at 50%. With NiMh they are a little more tolerant. I wouldn’t discharge fully nor over charge. At 5.0 per cell, take them off the charger. And I wouldn’t discharge them to zero either. The folded sheet is suspect. From a 50 year RC modeler.
That's my daily driver. Highly second the recommendation. If ever there's a doubt that a cell is bad, this can tell you. And if you want to make an attempt at restoration it's just a couple more button presses away.
I've had pretty good luck with IKEA NiMH's as well. Just make sure they're the versions that are made in Japan rather than China.get some Eneloops