> As you go up in the atmosphere things start to get really cold.
Yes, but the air is also much much thinner. So it doesn't suck heat away nearly as quickly as it might at ground level. So the batteries should retain heat.
I don't see the energy-density math. Batteries in passenger planes would have to last far longer than the flight duration, at least 30minutes more to accommodate safety margins such as diversion to other landing sites. And a battery-powered plane must suffer from the fact that it hauls around dead batteries. A gas-powered plane gets lighter as it burns fuel. So, by my math, an electric passenger plane would require an energy density at least four or five times that of current battery tech. The motor isn't the issue.
I still find the same issue with cars, they have to haul around dead batteries until recharged. They just have the advantage that they cannot fall off the earth. The weight has come down a lot for both applications, the idea we need to haul over 400kg of batteries for so little range is mind boggling. Of course with increased power density comes the issue of charging it quickly and safely.
Enough tech is here to make these types of cars a viable second or third car for many people but they aren't viable replacements in general. I am still surprised the government never pushed to move all school buses to electric, they have space and spare capacity to support them and ideal spots to recharge many times a day
I would assume a bunch of the battery usage would be from take off. You'd think they could design a system like a rocket launch with a "staged" plane launch, where the batteries used for take off would then be jettisoned to land safely back at the airport for re-use.
A while ago I read a proposal by airbus for an electric airliner. They speculated that batteries could be recharged on the way back down from altitude. If you want to recover energy, you;ll need those empty batteries.
If the batteries were exposed. But I assume they will be behind some cover, in relatively stable air. If the worry is that the batteries will get too cold, keeping them out of the wind is easy. (also, more aerodynamic)
Yes, but the air is also much much thinner. So it doesn't suck heat away nearly as quickly as it might at ground level. So the batteries should retain heat.
I don't see the energy-density math. Batteries in passenger planes would have to last far longer than the flight duration, at least 30minutes more to accommodate safety margins such as diversion to other landing sites. And a battery-powered plane must suffer from the fact that it hauls around dead batteries. A gas-powered plane gets lighter as it burns fuel. So, by my math, an electric passenger plane would require an energy density at least four or five times that of current battery tech. The motor isn't the issue.