4 ms·
I checked around, and a 2 kW dump resistor is about 3" diameter by 20" length. You'd need, say, 16 of those at a packing fraction about 0.5 for sufficent air fl
by semi-extrinsic 8y ago
I checked around, and a 2 kW dump resistor is about 3" diameter by 20" length. You'd need, say, 16 of those at a packing fraction about 0.5 for sufficent air flow, so you're looking at a cuboid which is 20" long and 4*3"/sqrt(0.5/0.9) = 16" to a side, or 2560 cu.in. Then you add the fans and the intake and outlet ducting etc. you can probably figure 3500 cu.in. total volume.
For comparison, the Model 3 "frunk" seems to be 28" x 15" x 9" = 3780 cu.in. So you'd have to sacrifice the entire frunk for your resistor pack.
- extropy 8y agoHow about just dumping that heat into the battery coolant loop. Oh wait.
- deleted 8y ago[deleted]
- etaioinshrdlu 8y agoI think there are still some reasonable solutions: * smaller resistive heaters with higher airflow * dump the heat into resistively heating the battery. Then use the battery again! * Just use disk brakes to achieve the same feel. Which is also, basically, dumping heat. Remember that the problem to solve is that a car shouldn't drive differently at different temperatures...
- therein 8y agoNow where could one get this said airflow in a vehicle moving through a medium that is commonly referred to as air? :) Heating up the battery with this airflow for a certain amount of time should warm them up relatively quickly and evenly since done via convection too. Now I genuinely wonder if there is a reason why Tesla didn't go with that.
- semi-extrinsic 8y agoFor something that generates a lot of heat when bringing the car (and air!) velocity towards zero, you really need to have forced air cooling available.
- anticensor 8y ago> dump the heat into resistively heating the battery. Then use the battery again! Will make your car prone to fires.