[Elecraft] KXBC3 "observations"

[Rich Heineck]

On 12/15/2012 3:44 PM, Peter Lambert wrote:
> I charged the batteries again overnight.  They were completely flat (8.2V)
> when I started the 16 hour charge cycle.  About 2 hours before the cycle was
> due to finish the display showed "not0-40C".  The ambient temperature was
> 27C, the PA 33C and the OSC 42C.  It's about an hour later now and the
> display still shows "not0-40C".  Another 15 minutes later and the charge
> cycle seems to have continued where it left off.
>
>   
>
> I guess my question is where is the temperature sensor used by the battery
> charger ?. (ie is it on the KXBC3 board which would be quite close to the
> batteries and this over temp indication really means batteries are in fact
> fully charged and starting to self-heat or is using the OSC temp sensor
> perhaps ?).

Hi Peter,

The temperature sensor is on the KXBC3 board and has pretty good thermal coupling to the 
side contacting the batteries in about the middle of the pack.  Charging will suspend when 
the temp hits 45 degrees C and will resume when it drops below 40 C.  With the specific 
conditions you describe, it's pretty likely the batteries are fully charged (or very 
close) when you get the "not0-40C" message.

73,
Rich  AC7MA