I’ve reached a state of analysis paralysis trying to sort out how to correctly power and motor control a set of 4 60v 350w hub motors usually found on segway mini pro’s. I’ve been searching all over trying to figure out what the right combination for controlling this beast is going to be. Considering the original scooter they were designed for was driving this around 54v nominal I’ve been looking at 52v ebike battery packs and that is about where I keep getting stuck. I’m considering using VESC flipsky esc for the controls but it would seem I may have little to no voltage margin as most of them top out at 60v. Then the question of current draw on the battery comes into question considering I’m driving 4 of these motors and how much margin I’m going to need in the battery to not stress out the battery. This particular rover isn’t designed for flat out speed, but instead will be autonomously moving around collecting soil samples. I’m honestly stuck trying to figure the math out on what direction to go so that I have margin and protection. Are my assumptions wrong about the 52v battery source? If anyone can help that would be awesome I’m open to any and all advice.
I use hoverboard hub motors on one of my rovers and 120kV brushless motors as hub motors on another rover. The hoverboard motors are rated for 36V. Would I try to run my rover with 36V, I would get an unloaded topspeed of 140kph. A little fast for my liking.
So I run it on 4s (16.8V) and it is plenty fast.
The other rover is also running on 4s and is even faster (smaller wheels, but 120kV). Would I dare to try it, it should go around 50kph.
Both rovers run Flipsky VESCs in FOC mode, with the hall sensors that are build into the motors.
The hoverboards use the high voltage to get enough power through thin wires. Their top speed is limited anyways and they need rpm headroom to keep the balancing going.
I never tested the maximum/stall current draw, but the motors of the 120kV rover never get warm, even after an hour of driving around.
Yeah I guess what I’m trying to work out is what am I trading off in the torque band if I stepped it down to 48v across 4 of these wheels. My napkin math says they will only be pulling 3-5amps per wheel on average but am I sacrificing a significant amount of torque? Not have a spec sheet is making this a little complicated.
Both rovers I talked about can pull 2 kids (30kg each) on rollerskates up a slight incline. One rover has two 10inch hoverboard wheels (plus castor wheel) and weighs 16kg. The other rover has four 1:8 RC wheels with a 120kV motor in each of them. This one weighs 8kg and struggles a bit with pulling the kids, because it has a short wheelbase and tends to do a wheelie.
Good to hear. I’ll wade in running a lower voltage for now, definitely will save some money on super expensive HV esc. Thanks for the encouragement