Anker SOLIX has called out an entire industry over how it measures battery efficiency, and it’s using its own product to make the point. The company has published discharge efficiency data for its S Series portable power stations across a range of real-world loads, something it says makes it the first portable power brand to disclose this level of detail. Anker has also shared its testing methodology alongside the results.The issue, according to Anker, is how efficiency gets advertised in the first place. Most portable power brands quote a single efficiency figure, typically between 89 and 92%, measured near full load under ideal conditions. But that’s rarely how these devices actually get used. During a real outage, you’re more likely running a fridge, a CPAP machine, a router, and some lights, all of which draw under 300W, well below 15% of a typical 2,000W unit’s rated output. Anker says efficiency at those lighter loads commonly drops to 70 to 80%, meaning a meaningful chunk of stored energy never makes it to your devices.