4 ms·

No need for the generator. Just a big battery onboard and a DC-DC converter.

rtkwe 8y ago
Generator is probably a better option for these though because then they can just get refueled instead of having to wait to get recharged themselves. It'd allow them to service more vehicles while being lighter.
- Reason077 8y ago
  Remember, you'd only need to charge each vehicle enough so that it can reach the nearest fast charger, so you wouldn't need a huge battery to service multiple vehicles in a day. Besides, how many "out of charge" breakdowns is a single service van likely to encounter in a day? A DC-DC transfer would enable fast charging rates with relatively compact and lightweight equipment. A diesel generator that can output, say, 100kW continuously is pretty big and hefty!
  - rtkwe 8y ago
    Those are still pretty sparse outside of California so the distance could be pretty far. Check out the list for NC there's 13 for the whole state at the moment.
    - Reason077 8y ago
      That's true. But by the time EVs make up a significant portion of the vehicle fleet in those areas (enough to justify a rescue van with onboard charging!), chargers will be much more common. Also, by nature, most "ran out of charge" incidents will happen near a charger (or near home, etc) because the driver thought they could make it. It's not likely that someone would drive off into some really remote area with no idea of where they would charge the car.
- gambler 8y ago
  While it would work, it would be horrible marketing for EVs.
  - sokoloff 8y ago
    Why would someone reasonably care what equipment is onboard the service trucks? I've never inquired as to what's inside the Mercedes Sprinter vans they use for roadside assistance when considering buying a Mercedes.
  - masklinn 8y ago
    It would be great for actual roadside assistance though, fuel is way more energy dense and energy specific than the best batteries, using batteries would mean way less ability to actually assist. An alternative would be an SMR (and possibly a bank of caps) but I don't think any of the currently working or even close to working designs would fit on a regular trailer (the KLT-40S seems to be the lightest working SMR at 80t with water, the rest is 150~1500t).
    - Reason077 8y ago
      A battery would work just fine. DC-to-DC transfers are efficient, and fast.
      - masklinn 8y ago
        Battery would greatly limit the amount of assistance which can be provided, and greatly increase the trailer's weight.
        Reason077 8y ago
        A diesel generator set that can output 100kW continuously for fast charging starts at around 2000kg / 5000lbs. You can fit a lot of battery capacity for a lot less weight that that!
        8y ago

Generator is probably a better option for these though because then they can just get refueled instead of having to wait to get recharged themselves. It'd allow them to service more vehicles while being lighter.

Reason077 8y ago
Remember, you'd only need to charge each vehicle enough so that it can reach the nearest fast charger, so you wouldn't need a huge battery to service multiple vehicles in a day. Besides, how many "out of charge" breakdowns is a single service van likely to encounter in a day? A DC-DC transfer would enable fast charging rates with relatively compact and lightweight equipment. A diesel generator that can output, say, 100kW continuously is pretty big and hefty!
- rtkwe 8y ago
  Those are still pretty sparse outside of California so the distance could be pretty far. Check out the list for NC there's 13 for the whole state at the moment.
  - Reason077 8y ago
    That's true. But by the time EVs make up a significant portion of the vehicle fleet in those areas (enough to justify a rescue van with onboard charging!), chargers will be much more common. Also, by nature, most "ran out of charge" incidents will happen near a charger (or near home, etc) because the driver thought they could make it. It's not likely that someone would drive off into some really remote area with no idea of where they would charge the car.
gambler 8y ago
While it would work, it would be horrible marketing for EVs.
- sokoloff 8y ago
  Why would someone reasonably care what equipment is onboard the service trucks? I've never inquired as to what's inside the Mercedes Sprinter vans they use for roadside assistance when considering buying a Mercedes.
- masklinn 8y ago
  It would be great for actual roadside assistance though, fuel is way more energy dense and energy specific than the best batteries, using batteries would mean way less ability to actually assist. An alternative would be an SMR (and possibly a bank of caps) but I don't think any of the currently working or even close to working designs would fit on a regular trailer (the KLT-40S seems to be the lightest working SMR at 80t with water, the rest is 150~1500t).
  - Reason077 8y ago
    A battery would work just fine. DC-to-DC transfers are efficient, and fast.
    - masklinn 8y ago
      Battery would greatly limit the amount of assistance which can be provided, and greatly increase the trailer's weight.
      - Reason077 8y ago
        A diesel generator set that can output 100kW continuously for fast charging starts at around 2000kg / 5000lbs. You can fit a lot of battery capacity for a lot less weight that that!
        8y ago