I like the Opus BT-C3400. It can charge a wide range of batteries: NiMH/NiCd sizes: AAAA, AAA, AA, A, C and SubC, i-ion sizes: 10440, 14500, 14650, RCR123A (17340), 17500, 17670, 18350, 18500, 18650, 19670 (protected 18650), 25500, 26500, 26650. It is even supposed to test for internal...