That's exactly what I was thinking. When I was growing up, my father owned a few gas welding rigs (he made jewelery, and a small acetylene or oxyacetylene torch was perfect for soldering silver and gold. The last time I visited his shop, he was using a hydrogen torch that ran on water and electricity). He owned the tanks, but whenever he went to get them filled, the gas supplier would actually trade tanks. The cost of periodic inspection, testing, and replacement of the tanks was built into the cost of the gas.Nanos wrote:> It reminds me of in the UK at least, with our bottled gas supplies that its pot luck whether you get a damaged/leaky bottle or not, as they are returned and reused, and people pay a deposit on them when they first sign up to use them.
It seems that model is exactly how a EV battery exchange service should work. Each battery would have a serial number by which its service history could be tracked, and would include electronics to monitor its charge and current capacity, and charge history, as well as other characteristics of the battery. The physical and electronic interfaces could easily be standardized, while allowing the actual chemistry of the battery to vary.
Each charge at a service station would consist of swapping out batteries and paying a fee which is based on the difference in charge between the old and new battery, and this would include amortized costs of battery replacement. Imagine standardized batteries holding a usable charge of 20kWh (a figure thrown around earlier), costing $5000 each, and capable of 3000 charges (on average) before retirement. The cost per kWh for the battery replacement is about 9 cents/kWh, or $1.80/full charge. If a service station services 100 cars a day, they'll have to buy a new battery every month, on average.
