My experiences are with K1, not KX1 but may generalize if I can manage to keep the form factor in mind. Also I use 18650 Li-Ion cells but use figures for 14500 cells below, as 18650s are too big for this application.
As others have mentioned, these cells require a specialized charge-discharge regime. For that reason I don't put Li-Ion cells inside radios, but I might if Wayne designed the charge controller. :) For the KX-1, 14500 series (AA-size) cylindrical Li-Ion cells should work nicely in 3S2P configuration with a protection IC/PCB for each of the two AA-size 3-packs to prevent overcharge/overdischarge and non-uniform charge distribution across cells. (As others have mentioned, the latter is a problem with Li-Ion cells that can lead to catastrophic failure). 3S2P configuration gives 11.1 volt nominal at 1500 mAh. Peak voltage is 12.3-12.6 volts depending on how they're charged, and it stays above 11.1 volts for a good long time ... 3 hours, say, with casual operating. The IC/PCB sheds the load when per-cell voltage drops to 2V, insuring long life and long-term rechargeability. Weight is around 4.8 oz and the new pack wouldn't require more and hence smaller cells (e.g. AAA-size) than the original design, presumably reducing the cost of a redesign. Cost is about 1/2 of equivalent Li-poly. Li-poly saves a little over 2 oz in weight, but some of the saving will be offset by the need for additional packaging to protect the fragile poly flat-pack. I fuse my pack at 2A and keep it in a plastic project box with a panel-mount PowerPole connector. I get this stuff from batteryspace.com - usual disclaimer applies. 73 Ken K3VV _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
