Battery Voltage Display

At competitions, I’ve seen teams have displays on the battery chargers showing the voltages on them. How do they do this and where can you buy the materials? Thanks.

You need an analog to digital converter of your choosing and basic electronics skills.

Or, if you want to be lazy, just get this.

Be aware that buying from the China warehouse can take quite a long time for shipment. The US warehouse costs a good bit more, but you usually get things more quickly

You could always just get a handy dandy LCD and display the voltage on there.

task LCD()
                string mainBattery, expander;
		bLCDBacklight = true;
		displayLCDString(0, 0, "Primary: ");
		sprintf(mainBattery, "%1.2f%c", nImmediateBatteryLevel/1000.0,'V');
		displayLCDString(1, 0, "Lift Bat: ");
		sprintf(expander, "%1.2f%c", ((SensorValue[importantVoltagePort])/270.0)-0.775, 'V');
		wait1Msec(100);//This has to be here or everything will go wrong and will look like the LCD is dying.

You can make your own with a part from Adafruit (underneath it all, it’s probably the same as the one linked above!). Full explanation in my article on batteries (this link goes straight to the build-your-own-voltmeter section). We have one. Love it. It’s not connected to our smart chargers directly; it’s a stand-alone item and pathetically easy to use:

  1. Plug in battery
  2. Read voltage in giant lighted numbers

How would you display the voltage while the battery is charging?

You would have to modify the charger, which (iirc) is illegal for competition.

Not necessary at all.

You would need to connect your ADC to the battery and charger while charging. This requires both a Tamiya male and female connector. And you should note the reading will be slightly high while charging.