s-DRIVE: up to 300% higher power-to-weight than drivetrains used by major EV brands

[freebeard]

Did it again.

So I watched the video again, the left/right modularity and good turning circle are nice plusses. Maybe they could dump regen into a heat sink and eliminate the brake altogether. (lay frame for parking. )

But I have trouble finding a second source. Searches on DDG are obfuscated by links to Salesforce and BMW s-drive.The website shown in the video is at https://www.s-drive.tech/ but it reliably crashes my browser, whether I accept all cookies or not.

I did find another story at www.cnet.com: This Donut-Shaped Motor at CES 2025 Could Transform the Future of EVs.

Alongside the 21-inch automotive wheel, Donut Lab also showcased an efficiency-focused semi truck version of the 21-inch wheel boasting a lower operating RPM, 200 kW and 2,212 lb-ft (3,000 Nm) per wheel. The lineup will also include a 12-inch scooter motor (15 kW) and a 120mm drone motor (3 kW). Donut's 150 kW, 17-inch motorcycle motor is already in use on the road for a few boutique electric bikes, so the odds of seeing this tech on a car in the future is better than you might think.

[Logic]

Originally Posted by freebeard

Did it again.

So I watched the video again, the left/right modularity and good turning circle are nice plusses. Maybe they could dump regen into a heat sink and eliminate the brake altogether. (lay frame for parking. )

But I have trouble finding a second source. Searches on DDG are obfuscated by links to Salesforce and BMW s-drive.The website shown in the video is at https://www.s-drive.tech/ but it reliably crashes my browser, whether I accept all cookies or not.

I did find another story at www.cnet.com: This Donut-Shaped Motor at CES 2025 Could Transform the Future of EVs.

The site uses 53MB of RAM and hardly any CPU; 0.something.
uBlock doesn't pick anything bad.
Strange... works fine here.

Donut looks similar and interesting.

[Piotrsko]

Since I have a controllable regen in the series powered Ranger, I can tell you regen won't replace brakes. For additional braking, it's awesome, double that for limiting downhill speed, but it's useless for low speed, low rotor rpm. Magnetic fields need to be moving to generate current, the faster, the higher generated. 120 volts generated during the 10 seconds during a stop won't recharge the 192 volt pack enough to notice on standard VOMs. Mqybe on a Simpson. Yes I could excite the field separately, but then it's isn't a series wound, it's a sepex and has a whole bunch of other control issues. Ditto for any other electric powered vehicle, only the efficiencies change

A plug brake on a forklift, now that is a different story.

[Logic]

Yep. The E-bike guys say their main advantage is more in not having to change brake pads as often.
(5 to 15% more range. See video)

More for Everyone:
Cars, being more aero, with higher velocity and more weight, are better suited to regen.
Ek = ⁠1/2⁠mv^2
NB the velocity squared
Trick is getting that kinetic energy back into the battery. Ek = ⁠1/2⁠mv^2

Although I'm no expert, I always think of parallel SuperCaps (and buck/boost etc controllers) in concert with (smaller) batteries.
They can take the amps and being low voltage; can be fed charge at the lower rpms where regen is normally ineffective.
But there's power to weight, cost and complexity to consider..?

As nothing is as efficient as freewheeling this is the most elegant/brilliant solution I have come across:
Once the penny drops here; the Ah-hA! moment/s are worth the video! Simply Inspired!
My research pointed to a ~20% efficiency boost from freewheel + regen IIRC.

https://www.youtube.com/watch?v=jeb2416X8Uk

[freebeard]

06-27-2024: ecomodder.com: Trick hub motor

[redpoint5]

Heading down Danger Hill tonight (12* grade) and 40F, the Tesla maintained 25 MPH with full regen (given the conditions). There was no further regen available. Had I wanted to go slower around the bend, I'd need to use the friction brakes. In this cold weather, braking on regen is extended quite a bit.

[freebeard]

I decided to make myself useful:


BMW i3 tires on a 4" rim have about the same rolling diameter as the stock 165-15s.

[I can't unsee that the front rim touch-up wasn't as good as the rear]

The owner used to sell eggs by the dozen out of the back of that Squareback.