Additional power supplies for Robots

If we use a co-processor, like raspberry pi, on our robot, can it have it’s own battery? I’ve searched FRC sites and forums and haven’t found a definitive answer. We’re prefer not to rely on the Rio and main battery because brown-outs can be a real pain for the pi.
I saw one team say they use a capacitor bank to hold charge during a brown-out. I haven’t seen anyone say they use a lipoly battery or something like that though.

You missed R39 in 2018. COTS USB battery packs (within the limitations) were legal for 2018.

Weird. I never noticed that before.

For anyone who think’s you’re serious (including you if you forgot) - yes, you have:

Well it was either that or I was going to have to do a lot more work with supercapacitors. :wink:

In all seriousness, there was a team in Michigan this year that showed up with a massive capacitor (like 2" diameter by 6" tall) in the center of their robot to regulate power to a Co-Processor. It raised a lot of eyebrows and pictures got passed around the FiM staff at various events that weekend. Not sure if they ruled it legal or not though.

I wonder if they had a diode in series, or if it was really stabilizing voltage on the entire robot? I don’t think you would need that serious of a capacitor if it was only regulating power to a processor.

Interesting but the physical size of the capacitor doesn’t concern me so much as the other properties of the capacitor and the circuit design.

Supercapacitors aren’t super because of their size. It’s their chemical composition, construction, and the fact that they wear capes.

We did it with a 58F cap and a very carefully designed circuit with multiple diodes and a high power resistor. It’s not a circuit I plan on publishing and now that the USB packs are legal, things are much easier.

I believe it was a 1 Farad capacitor if memory serves, and this was a younger team doing it (maybe even a rookie) so there were a few safety concerns (it also seemed like overkill).