Battery swapping madness

Thursday, May 30, 2013

Another day, another part of the electric car industry goes bust:

Israeli electric car company Better Place shutting down

Battery swapping is one of the dumbest attempts to work around the horrible problems of charging electric cars fast enough to actually be able to drive them further than the local store.

Batteries are not standardised, and no manufacturer has any real incentive to compromise their vehicles to make life easier for their competitors. A battery that works for a Smart car will not power an electric pickup truck for long, and an electric pickup truck battery will not fit in a Smart car. Sure, you could have ten Smart car batteries in the electric pickup, but you’ve just created ten times the work to swap them.

Ah, but you could have a standard pickup battery, a standard Smart car battery, a standard economy car battery, etc, etc. Great, you just need to store many times more batteries than you originally intended.

Which brings us to another problem. Battery swapping doesn’t allow you to charge your battery in five minutes, it just pushes the charging offline. That old battery still needs to be charged and will still require hours to do so, which means the charging station needs a backlog of batteries on charge to ensure they have enough when customers arrive to swap them. If you turn up and they’ve just swapped all the charged batteries… you’re still going to be waiting hours for the next one.

Batteries require heating and cooling to operate efficiently and safely. This process won’t be like replacing an AA battery in the TV remote, it will require detaching and hooking up multiple connectors with potentially catastrophic results if it goes wrong.

Batteries are heavy. Swapping will require moving more weight and bulk than a gasoline car engine into a precise position. Even though the batteries might be designed to be removed where engines typically aren’t, that’s still going to be a difficult process with the potential to cause serious damage to vehicles and workers.

Batteries decay over time. You might have a battery that gets the full advertised range, and swap it for a battery that only gets 80%. Leaving you stuck at the side of the road in Cannibal Redneck Country because you’d planned to swap for another battery at the full extent of the car’s range.

Worse than that, the battery is going to remain a large part of the cost of the vehicle. So you buy your $30k Civic-equivalent electric car with a $15k battery in perfect condition. Are you really going to want to swap it for a ten year old battery that only holds 50% charge the next day?

For that reason alone, the only way battery swapping can work is to lease batteries from the battery swapping company. But that further reduces the number of places where you can swap your battery. You run out of power and there’s a Chevy battery swap station a hundred yards away, but that’s useless because you’re driving a Ford.

It just doesn’t work, because it makes no sense for anyone involved. For electric cars to be viable, they need much faster charging and/or much greater battery capacity, and that makes swapping irrelevant.

Leave a Reply