Opus BT-C96 (4 bay, 9v NiMH charger)
The Opus BT-C96 is a 4 bay charger for 7.2, 8.4 and 9.6v batteries, typically just called “9v” batteries. This charger came with a regulated 15v wall wart but I have had no issues running it directly from 11-14.4 volts. I don’t even know where the original brick is. This charger can also refresh cells that are not holding a charge properly.