Here is a rundown of my thoughts and partial teardown of the BBB Brushed Featherweight ESC (v2)
For disambiguation, this is what we’re talking about:
It is supplied with a standard servo-style 3-pin dupont connector on a fairly long lead, which seems long enough for use a compact Featherweight robot, but those who build massive robots (aka use a lot of air armour) might need to use extension leads.
The power and output leads are nice and siliconey and 14AWG. Its official rating is “100A peak, 50A continuous” according to BBB parts wrangler, Joe Brown.
The ESC comes completely wrapped in quite tough feeling black heatshrink. Obviously I immediately removed that to find out what’s inside 
The internal construction is two circuit boards connected together by riser pins which are soldered. There is a chonky aluminium heatsink on the top which is stuck down with thermal paste (it won’t go anywhere inside the heatshrink tube)
The top circuit board contains the power bits, and it’s mostly MOSFETs. It seems that they use NCE3095K MOSFETs, What really surprised me is how numerous they are, there are 6 FETs per phase per side (=24 in total).
The MOSFETs are only rated at 30 volts, which seems a little low, especially if you run on 5S or 6S, as they need to resist any back-emf spikes from the motors. However, the sheer number of chips probably adequately compensates.
Unfortunately the way the wires are soldered to pads makes replacing the power wires difficult, I recommend avoiding that if possible. Replacing the signal wires looks a lot easier.
There are also brass rods soldered on to the board for better current capacity.
There is a 3A rated BEC hidden on the lower board too. I haven’t current-tested it, but it seems to work.
In general it seems very good. I installed one in my robot’s lifter and it seems to lift ok.I might be imagining it, but it seems there is a little bit of lag activating the lifter.
Pros:
- High current rating, which looks totally plausible and not exaggerated
- Extremely robust construction with loads of MOSFETs
- Firmware braking and safe start
- Good BEC
Cons:
- Fairly large
- Difficult to replace power wires
- No current limiting or endstop features
