[Elecraft] KX3: Eneloop Pro AA vs. Eneloop 21 AA cells

[Chip Stratton]

I've had 8 Eneloop Pro 2400 mAh cells in my KX3 for about 3 years now.
There have probably been only about 30 charge/discharge cycles on them,
since I most often use an external LiFePO4 pack when I can.

Just recently I've begun to experience KX3 shutdown when trying to transmit
at 5 watts or more into a well matched load - including a dummy load. At
the 3 watt level, the built-in voltmeter has shown a full 2 volt drop with
a 1.2 amp load: from 10.8 in receive to 8.8. This is fresh off a full
charge, and even though the cells still show about a 2400 mAh capacity with
a refresh cycle in an external battery charger/analyzer.

Replacing the Eneloop Pro cells with standard 2100 mAh Eneloops of
approximately the same age I don't have the problem. The 1.2 amp voltage
drop is 0.9 V and not much more when I transmit at 10 watts.

I had run across other's experiences with these cells that noted an
increased internal resistance compared to the standard Eneloops, and my
experience seems to confirm this. At the least it seems the Eneloop Pro
cells haven't aged as well as the standard Eneloops.

I thought this experience might help other KX3 owners.

73
Chip
AE5KA