[Elecraft] [K2] custom LiFePO4 pack

[inventor61 .]

Gents

Recently I saw some commentary regarding a LiFePO4 pack for the K2.

There is already one made specifically for the application, intended to
replace the gel cell option in the rig and to use the bracket provided for
same.  The picture on the web link below is slightly inaccurate in that the
wiring pigtail has a 'flying' lead so it is a 1:1 replacement for the
Elecraft gel cell assembly.

http://www.batteryspace.com/custom-lifepo4-18650-battery-12-8v-4500-mah-57-6wh-7a-rate-w-pcb-and-connector.aspx

As a *very* happy owner of this pack, I have to share that I am not
affiliated with the producer in any way.

This pack is purposefully made to charge using a LiFePO4 charger, available
from the battery supplier, via the radio's DC input jack, and works with
the battery switch on the K2 in a manner according to specifications I
provided.  Several design options were considered in the process of
creating the specs and I believe the best balance of these were selected.

When I am charging the internal pack with the LiFePO4 charger I am not
operating the radio (although it is possible); when I am operating from
mains, I use the KX33 supply from Pro Audio Engineering.

In some qualitative testing I am able to get roughly 80% more operating
time per charge than I was with the gel cell and at less weight.

The K2 is aging gracefully.  Newer radios for field use beckon but still
manage only to be just peers, not better.

Steve KZ1X