via：https://www.engadget.com/2017/08/25/the-best-portable-ac-power-supply/

If you need an AC outlet slapped on a battery, you don't have many choices—the 12 models we considered make up the bulk of the options when it comes to portable, affordable AC power sources. We split these models into two groups based on capacity and price. The first group of smaller batteries included eight models that were reasonably affordable and made sense for a carry-on, laptop bag, or backpack, so we focused on the most portable models—generally lithium-based units that weigh less than 5 pounds. The second group contained a handful of larger models for outdoor enthusiasts and field professionals that need more power than the smaller models can pack.
We charged each unit to full and then drained it using a 50-watt light bulb—our easily reproducible stand-in for a small laptop. We monitored the power usage and cumulative watt-hours with a simple Kill A Watt meter, and repeated the process three times. We then repeated this test using a 2012 11-inch MacBook Air to better simulate how people actually use these things in the real world.


KeyWords Tag：Preen AC power source supplier