Daimler and Tesla have been working together in a limited capacity for some time now, but the two made their relationship official in a pretty big way earlier today, with Daimler announcing that it has bought a 10% stake in Tesla, and that it'll be lending a hand with both parts and engineering. Of course, as with most things Tesla, there's no firm price tag attached to the deal, although it's said to be in the "double digit millions." They're a bit more specific when it comes to the working relationship, however, which will apparently include Tesla "leveraging Daimler's engineering, production and supply chain expertise" in ways that'll "accelerate" bringing the Model S to production. Tesla will also reportedly work on battery pack integration and battery management systems for Daimler from here on out, and the two will continue to collaborate on Daimler's second-generation Smart ED electric vehicle that's slated to go into production later this year. Interestingly, as AutoBlog points out, the deal also gives Tesla access to the automotive lithium-ion cells being produced by Daimler subsidiary Li-Tec which, when we're talking about electric vehicles, is no small thing.