I'm guessing batteries are distributed around the body to balance weight and save space. This means changing the batteries would involve stripping off all kinds of body work. That is risky, because it increases the opportunity for things to not be screwed back properly.

What this new series, with a lot of skeptics, do not need is an electrical accident.

So, I think is a safety reason. You can get one hell of a shock off these systems. Also, I'm sure the Williams' F1 KERS fire is in the back of many people's minds, even if not directly related.

I'm not sure weight distribution is the real reason since batteries can be shaped and conveniently packaged. They could fairly easily have long thin flat batteries running down the side pods, which could physically be swapped and secured. So, I do think its the disconnect/connect danger.

Swapping cars is clumsy, but I'm sure over time capacity and efficiency will increase leading to no stops for power.

It would be a huge engineering hurdle to make 400 lbs of battery swappable and still ensure that there is no chance of them coming loose during a wreck due to being seated improperly, etc. I think it is a safety consideration more than anything.

I hate the idea but it's probably because swapping the battery would slow down the race and instead of the usual quick pit stop it might be a 10-15 minute pit stop given the weight of the battery at 400+ lbs.

I wonder if they replaced them with fuel cells, would that be an easier on the swap? Could they then just "fuel up" like a petrol-based vehicle?

It seems like a missed opportunity to push for innovation. Changing tyres on normal cars is also a slow process and back in the earlier days of racing it was as well. Now all four tyres can be changed in just around 2 seconds due to great technological innovations (and training the pit-crew like OL athletes). Developing a system where a battery could be changed quickly would be equally as interesting.

The extensive crew training, and having a crew, and having air tools, and having a car that is jacked in a single push motion, all make changing F1 tires easier.

I'm not sure what can be transferred to regular cars? How often do tires need to be changed? (I guess more often if you have snow and ice some times of year?)

Agreed. I'm hoping to see that in the Le Mans series as manufacturers bring electric vehicles into the mix. Such as Nissan's entry next year: http://www.theregister.co.uk/2013/06/22/nissan_electric_le_m...

They want to compete with petrol cars not only on the track, but also in the pits.

Le Mans is really just one big automotive experiment, with a lot of the technology trickling down to the rest of us. That's why I love it.