4 ms·

Capacitors make much more sense than batteries, since you need to discharge at like 2-4C average, probably 20C peaks, and charge at much higher rate. Some buses

by phh 4y ago

Capacitors make much more sense than batteries, since you need to discharge at like 2-4C average, probably 20C peaks, and charge at much higher rate. Some buses are already running with this, for instance: https://www.youtube.com/watch?v=nlJlQprrEmg https://www.youtube.com/watch?v=nlJlQprrEmg . So far it doesn't look like there is much interest in it, since I'm not aware of any further development since that 2014 line.

stevesimmons 4y ago
Minsk in Belarus runs a network of super-capacitor powered buses. I travelled on one when there in 2020. Just like a normal bus from the passenger's point of view. https://eng.belta.by/economics/view/belarusian-electric-bus-vitovt-now-in-use-in-tashkent-124894-2019/ https://eng.belta.by/economics/view/belarusian-electric-bus-... "The bus is fitted with a system of super capacitors, which get fully charged within 5-10 minutes while the bus is at an end stop. The bus can travel along the entire distance of the line for up to 15 times per day. On the first day it managed to travel for over 40km on one charge."
Reason077 4y ago
Capacitors are power dense but not energy dense, compared to batteries. So for a given size/weight, you get a lot more range with batteries. There has been some work, a few years back, using super-capacitors (alongside storage batteries) in high-performance electric cars to increase peak power output. But really, battery technology has improved so much that it's made that sort of thing unnecessary. Even your standard Tesla is pulling 8-10C if you really put your foot down.
- phh 4y ago
  > Even your standard Tesla is pulling 8-10C if you really put your foot down. How long does your battery keep usable if you do that at every single stop? (so every 2 minutes, let's say 300 times a day ballpark)
  - Reason077 4y ago
    Hah! Nobody sane is doing that at every stop. For one thing, it shreds your tires. But for the ones who are doing it repeatedly (at the track), the answer is: very effective battery cooling! Tesla's software in their performance models actually offers a special "track mode" which, amongst other things, applies max cooling.

by phh 4y ago

stevesimmons 4y ago

Minsk in Belarus runs a network of super-capacitor powered buses. I travelled on one when there in 2020. Just like a normal bus from the passenger's point of view. https://eng.belta.by/economics/view/belarusian-electric-bus-vitovt-now-in-use-in-tashkent-124894-2019/ https://eng.belta.by/economics/view/belarusian-electric-bus-... "The bus is fitted with a system of super capacitors, which get fully charged within 5-10 minutes while the bus is at an end stop. The bus can travel along the entire distance of the line for up to 15 times per day. On the first day it managed to travel for over 40km on one charge."

Reason077 4y ago

Capacitors are power dense but not energy dense, compared to batteries. So for a given size/weight, you get a lot more range with batteries. There has been some work, a few years back, using super-capacitors (alongside storage batteries) in high-performance electric cars to increase peak power output. But really, battery technology has improved so much that it's made that sort of thing unnecessary. Even your standard Tesla is pulling 8-10C if you really put your foot down.

phh 4y ago
> Even your standard Tesla is pulling 8-10C if you really put your foot down. How long does your battery keep usable if you do that at every single stop? (so every 2 minutes, let's say 300 times a day ballpark)
- Reason077 4y ago
  Hah! Nobody sane is doing that at every stop. For one thing, it shreds your tires. But for the ones who are doing it repeatedly (at the track), the answer is: very effective battery cooling! Tesla's software in their performance models actually offers a special "track mode" which, amongst other things, applies max cooling.