23 July 2009

From 0 to 100% battery capacity... in TEN MINUTES?

Yeah, that's the goal of the egg-heads at MIT. Check this out:

From Engadget
Video: MIT working on rapid recharging for electric vehicles

Wow! I wish WE could charge the Mini-E in 10 minutes!!!

Here's the MIT blog on the project:


And here's their latest video!


  1. Hmmm. Actually you have very similar batteries in your Mini-E, and while I think 10 minutes is a bit of a stretch, you can actually charge your car NOW in 20 minutes, and be quite within the manufacturers specs on the batteries when doing so. An hour would be better on the long term life of the batteries, but with a year lease, it wouldn't matter much to you.

    The problem is not the batteries or developing any new technology at all. The problem is getting that much power. Where?

    You're 240 vac "charger" isn't a charger at all. It's simply an AC source. And it's limited to about 40 amps. The battery charger is actually in your car. It converts 240 vac to some 350+ vdc to charge the batteries.

    You have a 350 vdc 35 kWh battery pack. To protect the pack, your use of the pack is limited to 80% DOD or about 28 kWh. To put 28 kWh back into your pack requires about 80 amps at 350 vdc (really more like 380 vdc when charging) for an hour. To do so in 20 minutes requires 240 amps at 350 vdc - well within the specs for your batteries.

    But your charger (real charger - in the car) won't do that. Essentially no commercially available charger will. The AC source in your garage certainly won't. You probably have a 200 amp 240 vac to your whole house, although some homes do sport 400 amp service now. But there is still no charger that will convert it.

    Here's what I'm doing. We're building a "mother" battery bank out of old lead acid batteries. In your case, say 400 volts long and two strings in parallel. You can get a charger that will do that, slowly. Typically at about 12 amps DC. So it will take about a day to charge the mother bank. Actually we plan on charging ours using a 10 kw photovoltaic array.

    Then you pull your car into the garage and charge the MiniE battery pack off the battery bank sitting in the garage. It CAN put out 400 volts at 240 amps for an hour. You have to use very heavy 2/0 cables. And it has to connect directly to the battery pack, bypassing your controller/charger. But it will work. You could charge in 20 minutes.

    Probably not 10 minutes. And the guys at MIT won't achieve 10 minutes either, not without seriously damaging some batteries. Altair Nano is working on a battery chemistry using Lithium Titanate Spinel on the Anode that might just do 10 minute recharges safely.
    They're not yet available.

    We're converting a 2009 Mini Clubman right now. A little more storage room. A little larger pack. And probably a little better motor than the Mini-E. But the same idea. We're doing a series of videos on how to do it. So if you really like your Mini-E and they really do make you give it back after a year, you can still build your own.

    Jack Rickard

  2. I'm reading some 10-15 "E" blogs this AM and see very happy E'rs and very unhappy e'rs? Some pissed at the fact that municipalities are paying$10 a month some pissed at electric costs, some are driving rental cars because MINI is fixing their E's and don't like the gas powered Kia they got and some like you just enjoying the car.