Never heard of A123 Systems? There's no reason you should have, unless you've been following the news of its recent bankruptcy. The battery manufacturer doesn't make any of its own cars, but it does supply lithium-ion cells to a broad range of automakers, including BMW (for the ActiveHybrid versions of the 3 and 5 Series), GM (for the new Spark EV) and Chinese automakers Geely and SAIC. It also supplies the starter battery for the McLaren MP4-12C, and the power pack for the Fisker Karma.

Just like any other automaker, these companies rely on component suppliers like A123 to provide them with a continuous flow of parts integrated into their designs. But when such a supplier stops supplying, it can have an arresting effect on vehicle production. While A123 Systems tries to find a new buyer under bankruptcy protection, it has ceased production, but the effect on two of its higher-end customers is very different. On the one hand, Fisker has halted production of the Karma while it waits for the Delaware courts to clear the sale of A123 to Chinese component giant Wanxiang.

In the meantime Fisker hasn't built a single car for the last six months, and won't resume production until A123 does, and that hinges on Delaware courts approving its sale to Chinese component manufacturer Wanxiang. McLaren, on the other hand, says it has stockpiled enough of the starter batteries for the MP4-12C to carry on production for the foreseeable future. Good call, McLaren. Hopefully it also has enough for the upcoming P1 (which, like the Karma, is a hybrid) - or has contracted with a more stable supplier. One way or another, it only goes to show that there are plenty of things that can delay an electric car, but nothing can slow down a McLaren.