A graphical look at the main advantage of the KX2USBC2

I've now gone through six charge/discharge cycles of my KX2's internal battery using the new KXUSBC2 to charge it and I've used different sources and USB-C cables for each charge.

Regardless of the charging voltage used, the KX2 battery gets a complete charge, whether the charging source was 5V or 15V.

Contrast that with different source voltages when used with Elecraft's KXIBC2 internal charger:

Cheap DC-DC converter for QRP with batteries

My recent outtings with the mcHF on battery power have made me realize, once again, that there is always a compromise to be made when matching battery type to the rig's maximum safe input voltage level. Quite often, a 3S battery will be a couple of volts less than the radio's maximum level but a 4S pack will exceed the radio's rating.

The ramifications are minimal and may not seem to make a significant real-world difference but consider the 25% variation in maximum permissible input voltages of several QRP rigs:

• mcHF - 16v
• KX2, KX3 - 15v
• Anan-10E - 14v
• MTR-3B - 12v

A battery that is safe to use with an MTR-3B will underpower my mcHF, decreasing its 10-watt output to 6 watts.