That is a very clear how to video. It might be useful to know more about the meter-how much did it cost? Where did you get it?
You made clear that battery testing was important because 1) it identified bad batteries and 2) that if you have two packs, you should run your best batteries as a pack and your less strong batteries as the other pack because a pack will only deliver energy until the weakest cell is empty despite the other cells still having a charge.
Other uses of this set up include trying different charging methods so the team can learn how to charge a battery to get the best energy capacity. You also showed you were tracking temperature. This could help find the optimum temperature to run the battery at to get the most energy out.
But to me, the biggest advantage is that if I know my pack capacity, I can set my pace to use the energy consistently through the race. It is more effective to run an even pace than to run fast at the beginning and slow at the end or visa versa. If the car has a meter like the one in your video they can either try and 1) run a set power to match their capacity. 2) run a timer as well and compare the Watt Hour reading to the time-for example at the 15 minute mark, the Watt hours used should be 1/4 of the pack's capacity.
At ProEV, we have gone a step further and track energy usage per lap while the Arduino program calculates on the fly whether we can finish the race based on lap time and energy usage. We use a GPS to tell the computer when the car crosses the Start/Finish line.
All of these methods are only as good as your information about your pack capacity which is why this testing is important.
For those who are testing a lithium pack, you need to watch the voltage of each cell in series during the discharge rather than the whole packs voltage. The R/C model market sell inexpensive meters that do 6-8 voltages at once.