Yep, all good except I think you meant to say "1/0.6 hours" in that second-to-last sentence. Another thing worth keeping in mind is that discharging (most) Li-i

Yep, all good except I think you meant to say "1/0.6 hours" in that second-to-last sentence. Another thing worth keeping in mind is that discharging (most) Li-ion batteries below a certain voltage is harmful, and thus you can only usually "get" 80% or so of the energy out of the battery. In simple terms, C rating is how fast you're draining the battery. Most batteries are rated for between 1 and 10C. This is the runtime you'll usually get from C ratings: 0.1C/10.5hr; 0.2C/5hr; 0.3C/3hr; 1C/55min; 1.5C/35min; 2C/25min. You'll notice how this doesn't track the expected values perfectly; for example, at 0.1C you get 5% more runtime but at 2C you get almost 20% less. This is because at 0.1C heat is negligible, but at 2C you're discharging almost 30 watts per cell. A good rule of thumb when running over 0.2C is to subtract five minutes from however long the cell "should" be able to run. You can probably now see how discharging at over 10C is tricky. Discharging at a lower current produces less heat and increases the cycle lifetime, as well as a few other things (e.x. decreasing the risk of explosion.) Since Tesla is discharging these at 0.6C, they will get more cycles out of them than if they discharged them at 1C or 10C, for example. The number of cycles is very important here because these will be used at least one cycle per day, and given that most batteries have a lifetime of 200-500 cycles this is a maximum of 200-500 days. Given that there are 16-20 million dollars worth of batteries here, that represents a significant yearly cost.