Electric cars are still absolutely terrible as far as efficiency and where you can charge the damn thing. There is so much wrong with trying to force the switch right now, our governments want to buy into this bullshit too early.
Maybe this is a stupid question, but I have wondered, why aren’t there on-board generators, like an alternator, to charge the batteries? Can’t that be done? Transform the mechanical energy of the rotating wheels into electrical energy?
Short answer: thermodynamics says you can't get more energy out than what you put in. If the batteries are moving the wheels, then any generated energy also would have to come from the batteries, making it essentially the same power as just driving the wheels.
That said, most/all electric cars do have regenerative braking (as do diesel electric trains) - meaning that if the car needs to slow down, either for a stop, or going down a hill, etc, then the car doesn't need to apply brake pads, but use the wheel "motors" as generators and charge the batteries to use up the excess speed. This process is very short term over the course of a trip, so not much is recaptured.
A good size estimate for a generator is to look at the hp of hybrids in terms of what size alternator would be needed to charge the batteries while in use.
Another issue is weight. The device in the video works because it can produce more thrust than the weight of the vehicle. Add in safety features and a driver (and 4 passengers) and the vehicle will need external power to drive it again.
The best example of a mechanical advantage system that I haven't quite run the numbers on yet is that treadmill to scooter device.
Aside from the electric assist, it does look like there may be some gearing that converts walking energy into biking energy. Bicycles themselves are around 80% more efficient than walking, so it may still be that a true bicycle outperforms the treadmill scooter in raw muscle power.
I think the doctors that buy new raptors might look at these trucks. Regular people don't want an ultra expensive electric truck they can't really use as a truck.
[ + ] 1Icemonkey
[ - ] 1Icemonkey 0 points 3.3 yearsFeb 3, 2022 23:46:27 ago (+0/-0)
[ + ] Her0n
[ - ] Her0n 0 points 3.4 yearsNov 27, 2021 11:30:02 ago (+0/-0)
[ + ] localsal
[ - ] localsal 0 points 3.4 yearsNov 27, 2021 12:29:23 ago (+0/-0)
Can't get more than 2 charges in a day - even if chargers were everywhere.
How many people want to sit around for hours while their car is charging?
[ + ] Her0n
[ - ] Her0n 0 points 3.4 yearsNov 28, 2021 01:44:21 ago (+0/-0)
[ + ] 1Icemonkey
[ - ] 1Icemonkey 0 points 3.3 yearsFeb 3, 2022 23:53:43 ago (+0/-0)
[ + ] localsal
[ - ] localsal 0 points 3.3 yearsFeb 4, 2022 01:40:01 ago (+0/-0)
Interestingly, there is a machine that seemingly breaks the laws of physics:
https://www.youtube.com/watch?v=VUgajGv4Aok
Short answer: thermodynamics says you can't get more energy out than what you put in. If the batteries are moving the wheels, then any generated energy also would have to come from the batteries, making it essentially the same power as just driving the wheels.
That said, most/all electric cars do have regenerative braking (as do diesel electric trains) - meaning that if the car needs to slow down, either for a stop, or going down a hill, etc, then the car doesn't need to apply brake pads, but use the wheel "motors" as generators and charge the batteries to use up the excess speed. This process is very short term over the course of a trip, so not much is recaptured.
A good size estimate for a generator is to look at the hp of hybrids in terms of what size alternator would be needed to charge the batteries while in use.
Another issue is weight. The device in the video works because it can produce more thrust than the weight of the vehicle. Add in safety features and a driver (and 4 passengers) and the vehicle will need external power to drive it again.
The best example of a mechanical advantage system that I haven't quite run the numbers on yet is that treadmill to scooter device.
https://www.youtube.com/watch?v=b_L4QMOvH2o
Aside from the electric assist, it does look like there may be some gearing that converts walking energy into biking energy. Bicycles themselves are around 80% more efficient than walking, so it may still be that a true bicycle outperforms the treadmill scooter in raw muscle power.
[ + ] ruck_feddit
[ - ] ruck_feddit 0 points 3.4 yearsNov 27, 2021 10:21:53 ago (+0/-0)