[Al Skierkiewicz]

Karin,
It is not unusual for the battery to fall to 9 volts with a fresh battery while driving around. Short duration dips to 5 or 6 volts are not uncommon. It is important to note the battery voltage after two minutes or more. If the battery generally stays above 6 volts while driving, the batteries are likely OK. If you can't make it through a complete match without resetting the Crio and/or the radio, then you might have a bad battery.
The battery checker that Ether has linked can duplicate the testing done by the manufacturer and give you a plot and amp hour calculation. I recommend a discharge of 7 amps and a test stop voltage of 8 volts. The curves can then be saved and each test you make of the same battery can be overlaid with the previous tests to show if your battery has changed or has reached end of life.
Please remember that the 12 volt connection to the Crio analog module and the jumper on that module are used to sense the battery voltage and provide the reading on the dashboard. If the voltage dips to about 5.5 volts, the Crio disables all output, which temporarily stops all motor function. If the battery voltage falls to 4.5 volts for a short duration, the power supplies that feed the Crio, camera and radio will reset and so too will the devices they feed.