I use EBL or Eneloop AA rechargeable batteries in the black holder. Works fine with the 164. I charge them using an external charger and not in the scanner. I have been doing this for years, perhaps more than a decade. The Eneloop are better as the EBL loose their charge faster even when not connected to anything. I always carried a spare set of four AA in a holder in my vehicle as well to swap out.
* I switched to the Uniden 125AT which only uses two AA batteries and has a USB power input on the side. A small battery bank keeps it powered up fine using a short USB cable.