[Elecraft] KX3 Battery charging

[Peter Eijlander (PA0PJE)]

And do not forget that the supplied voltage needs to be correct to 
charge the cells.

I use 2400 mAh cells (Sanyo Eneloop XX) without any problem.

As stated in the KXBC3 manual:
only NiMH cells rated at 1900 mAH or greater may be charged with the KXBC3.

As far as I know the voltage applied should be more than 13.5 volts. 
Using a standard lead-acid battery as a source will not work.

However I have tried to lower the voltage while charging. At 13.8 Volt 
the current drawn from my power supply is 330 mA. Initially I could sink 
the voltage to  12.7 Volt keeping 330 mA. Under that voltage, current 
dropped gradually and at 12.0 I got the "low supply" message on the KX3 
display. While charging, the voltage needed to be increased at times to 
maintain the 330 mA current flow and the "low supply" message showed at 
12.5 volt, which proves that you cannot get a full charge on that 
voltage level.

The bottom line is: Use a power supply that can deliver at least 0.5 
Amp. at 13.8 Volt as a "charge only" option.



73,
Peter - PA0PJE

Op 2013-04-06 21:22 schreef Matt Zilmer:
> Any capacity NiMH cells are OK.  They will charge at the rate of 200
> mA.  Your 1900's should charge from 0SOC to fully charged in about ten
> hours.