I only buy Fenix AA Rechargable Batteries
"I have tried other brands and now, I only use Fenix. the space where you plug in the other batteries eventually get loss, and no longer charge properly without jiggling the cable. Never with Fenix. In fact, in the ten years have been using rechargable batteries for all my microphones, I have never thrown away a fenix battery - they keep going, and going. I gifted my first generation to someone when the labels had worn off completely, and bought new ones for myself. But you don't throw away a Fenix batteriy - other brands, I have had to toss them."