The rugged and compact Ace R/C Digital Voltmeter is designed with the R/C hobbyist in mind.
It checks all batteries up to 20 volts and indicates the voltage in a clear, hi-vis liquid crystal display. It also puts a load on both the receiver and transmitter battery so the voltage reading provides a valid determination of whether you have enough energy for another flight or run. A go/no-go green/red LED gives a quick visual reference of charge condition.
Comes with test probes. Requires a 9V transistor battery.