RE: Expensive US made vs Chinese Batteries
There's actually a bit more to it than that. Few of us run our batteries at more than 10c aside from just small bursts. A 10c constant discharge will give you 6 minutes of flight time before you reach the low voltage cutoff, so very few of us would push our systems that hard. So truthfully, "C" ratings don't mean much. What they can indicate is better internal resistance (not always though) which means the battery can maintain voltage better under load and not heat up as quickly. That will translate to more power and better battery life. There are numerous tests that have been done to establish what various batteries do under real world and simulated flight conditions, and if you read up on a few of them you'll find that the internal resistance value (which few manufacturers report) is the real magic number. Under the same load, batteries from various manufacturers can vary significantly in the actual power they produce, with lower C rated packs from a good manufacturer outperforming higher C rated packs from another.