Nominally technical (but probably super-obvious) question about how we measure battery capacities... My son recently acquired a radio-controlled car (in case anyone's wondering it's a Traxxas Stampede 2WD). It has a battery pack that's rated for 3000 mAh. It has 7 NiMH cells in it, which produce a output of 8.4V. I'm trying to understand how that compares to the battery pack in a full-size EV, such as my Model S 85D, whose battery pack is rated in terms of kWh, let's assume for sake of argument it really holds 85 kWh even though we know it doesn't. I got hung up on a couple of questions I can't find the answer to: 1. How do you talk about these two battery packs in the same units of measurement? For the RC car, if you multiply the 3000mAh rating by the nominal output voltage, you can at least get something in terms of Wh (25.2Wh?). RIght? Or is there some other formula or correction factor needed? 2. Why are the capacities of the two types of battery packs given in different units? Shouldn't there be only one unit of measurement for battery capacity? (By the way, one of the reasons this topic came up was because the Traxxas Stampede comes with a battery charger that plugs into an automobile 12V outlet, so apparently I'm supposed to use my EV to charge his RC car. I ended up buying a 110V wall charger instead!) Thanks in advance for a clue... Bruce.