[Elecraft] KX3 vehicle mount

[Josh Fiden]

How I understand it is that the sensor is measuring charge/discharge 
current of the battery.

The following assumes the radio is connected directly to the battery 
terminal:

Case 1. If the alternator is running, then current to the radio is 
passing through the sensor which looks like charging current to the battery.

Case 2. If the alternator is not running, then the current to the radio 
is discharging the battery, but not being registered by the sensor.

If instead we connect the radio's negative supply to the chassis ground 
side of the sensor, then the sensor can correctly measure when the radio 
is discharging the battery.

Caveat: my understanding of this is from the fount of all knowledge, 
i.e. I read about it on the internet! If I got it wrong, someone please 
correct.

73,
Josh W6XU

On 9/12/2016 5:56 PM, Jim Brown wrote:
> Thanks Josh.
>
> To confuse the sensor, it seems to me that the sensor would need to be 
> built into the battery lug, so that it was between where we could 
> connect our 12V minus lead and the battery -- i.e., so that our 
> current was going through it.  I was assuming it was on the wire side 
> of the battery lug. I haven't seen one of these things, so I must 
> plead ignorance.
>
> Thanks and 73, Jim