[CamperBob2]

Batteries are heavy no matter how you slice 'em. They will always (AFAIK) offer terrible joule/kg performance compared to a tank of gasoline.

I don't think replaceable modular batteries would be that much heavier than whatever's being done now. But yes, there would be some additional overhead, given that even the smallest cars would probably take more than one battery module.

[001sky]

The UPS and the Airplane luggage guys though will only 30 kilos (65lbs), though because of insurance/workplace comp. They wont let them lug more. at 200 kilos (440lba) you are talking splitting the pack up into 6 or 7 parts (and still be laboriously removed) or having a somewhat major operation on your car (ie, you need an Engine Hoist for the thing in one part) to change the battery. Then a forklift or something to put them on a "rack". Seems logistically like a nightmare.

That being said, the actual cells themselves are only a couple of pounds each. Would be interesting if this could be engineered to just take out something like the 100 micro-cells (at 4 lbs each), and toss em in a shopping cart. Maybe have a robot then sort and charge them in a special room full of charging racks. (like automated library book retrieval). But they would need to be built up in a certain way, and put in a housing, etc to go back in the car OK.