Hi. This thread is helping me understand the Approach G5. I'm using rechargeable Eneloops as well. Can you advise if you can charge the Approach G5 in the unit using USB port / charger or do they have to be removed, charged externally and reinserted? Thanks in advance.
Here is a link to the manual - Approach G3 and G5 Owners Manual
The important information on batteries is found under Installing Batteries on page 1 and the top of page 2. You will need to recharge your lithium batteries or NiMH rechargeable batteries outside of the unit. Do not charge them within it. It is also important to remove your batteries if not using it for several months. It will still maintain its internal memory as long as the internal built-in memory backup battery is still good.