Hello, I rarely post here, and maybe this is a bad question but I was wondering:

Why not make a car frame that also serves as a very large series of nickel-iron battery cells, or in other words combine the frame and batteries to reduce weight (compared to having a similar weight of batteries added onto an aluminum frame, at least). Obviously this would be much, much more heavy than an aluminum frame and carbon fiber body, but you'd have a very large storage of deep cycle amp hours. It could vent hydrogen in 'exhaust' and be topped off with water.

Making a whole frame out of daisy chained batteries means a much higher voltage to overcome the low specific energy, and having a very large number means both a low depth of discharge on average and also a high range when necessary.

Since the weight of the nickel-iron batteries is the primary limitation for their use in electric cars, I just thought I'd find out if anyone had considered this. I know there might be environmental concerns for the batteries breaching in car accidents, and corrosion issues, and the dynamics of having liquid inside your frame sloshing as you round bends, but those concerns could probably be overcome if the 'theory' of this idea has any merit.

I looked at nickel-iron batteries that are available commercially and they are astronomically high in price, but I saw something written by Marcin that seemed to suggest that weight was the primary hurdle, rather than cost.