[Elecraft] [K2] LiFePO4 replacement for internal SLA battery in K2

[inventor61 .]

Hello

My older K2, #771, is still in use after almost 16 years since I built it.

I have the internal sealed lead-acid gel cell battery option.  I have the
charge circuit slightly modified using the kit from ProAudio Engineering,
and I use their superb external power supply as well.

I get great results, but I know one day this battery (the 2nd I have had)
will eventually need to be replaced once again.

I contacted Batteryspace.com and asked them to fabricate a LiFePO4 pack
that matched the dimensions of the SLA in my radio, and to also include a
matching Elecraft pigtail to plug in to the PCB connector, with a
protection circuit board to prevent over discharge, shorts, and the like.

The SLA is rated at 2.9Ah and the new LiFePO4 pack is rated at 4.5Ah.  The
new pack also has the benefit of running at a slightly higher voltage for
most of the longer discharge curve.

One key operating difference versus the SLA is that you should not
continuously float charge the LiFePO4 pack.

The new pack is not inexpensive, but it roughly doubles both the discharge
period and the cycle life of the SLA.

The new pack has shipped and I expect to get it after Labor Day / Shelby
weekend.  The pack has to come via ground (to NC from W6) due to the hazmat
restrictions on such cell packs.

If you look at their website, the pack is now listed :: item CU-J1087 (prod
id: 9647).

I will report back here after I get the pack and try it out.  I am not
affiliated with this firm in any way.  Rather, I am reporting this
information as a courtesy to the other Elecrafters who recently mentioned
the need to replace their K2 SLA batteries.

73

Steve KZ1X