[Elecraft] NiMH batteries How do I test?

[Mark, KE6BB via Elecraft]

Jim,

Good descriptions from Ray and Bob.  You are also right in that the KXBC3 has some "smarts", but it is constant current temperature monitored charger.

You may also see the display message "Not 0 to 40".  It means the cell temperatures are not within the temperature range of 0 to 40 deg. C.  If it occurs on a cold day at the beginning of a recharge cycle, the cells are probably too cold to be charged, but the most likely time you will see it is near the end of a recharge cycle on a warm day.  As the cells near full charge, they convert more and more of the 200 MA charge current to heat rather than into the chemical process of recharging.  That is how NiMH cells work when recharged with a constant current.  The KXBC3 will suspend charging until the temperature drops below 40 deg. C.  

This is all normal operation, and is the most common method for recharging NiMH cells.

Mark
KE6BB