I want to add a Lipo Voltmeter like this to my Intellicharge i4.
I opened the charger and noticed that each bay has a separate GND but these testers have only one common GND.
Does someone know why the GNDs in the charger are not connected?
Do you think i can connect them without damaging the charger or the cells?
Why not just use 4 1s-6s Li-Po checkers? ….If space permits.
It is set up with 4 separate grounds because it senses each channel individually.
Do not connect the grounds.
If you want to measure each channel, your choices are a 4 way switch to allow you to measure each channel, one at a time using one meter.
Or use 4 meters, one for each channel.
HTH
Keith
thanks for your suggesstions!
i looked a little closer and realized thad the mosfet “switches” (ME9926) are between -bat and ground.
that disqualifies the lipo checker because it would measure the bat voltage and the voltage drop over the mosfet when connected to ground 
4 separate voltmeter sure would look cool but i don’t know if they will fit.
so the switch solution seams to be the winner.
connect +bat and -bat of each bay to a 2P4T switch and the output to a voltmeter.
At first i thought about a 3wire voltmeter. It has an additional power wire and can measure down to 0V. But then the charger has to be plugged in for the voltmeter to work and when i put in a cell it starts charging. A 2wire voltmeter can only measure down to 3.3/3.2V but when i put a cell in the unplugged charger the voltage of the batt will show.