pic: 4908 Prototype West Coast Drive

[RoboChair]

Back when we used the cRio, this was more viable. Now that we have the RoboRio you need to exercise much greater care to prevent costly brown-outs. You NEED current sensing in your code for this to be worth it, and probably some form of auto-shifting to get the best use out of your power available. When we did 6 CIM in 2014 all we had to worry about was popping the breaker. We would not do another 6 CIM with the RoboRio without a lot of thought about how to implement it well.

[Bryce2471]

My team (2471) competes in an off-season competition called bunnybots every year. This year one of the major components of the game is going around a race track. I realize this isn't a normal drivetrain application, but I thought you might be interested in a data point or two.

Both robots are running 2016 legal electrical systems. One is 4 CIM and 2 mini, geared for roughly 18fps free speed (Mini CIMs are compensated for in gearing). This robot usually doesn't brown out in a pushing match because the 2 mini CIMs are in their own transitions and usually spin out. However we have not tried a lot of pushing match senarios.
The other bot is running a 6 CIM two speed drive geared for 9.5fps and 24.5fps free speed. It has auto-shifting code but no current monitoring yet. This robot only browns out when the battery is too low (aka 12v rested after ~8min of driving like crazy). One thing to keep in mind is that both robots are about 80lb without bumpers or battery.