New recommendations for outdoor power supplies

The U.S. Department of Energy (DOE) has recently proposed new energy conservation standards for External Power Supplies (EPSs). These proposed standards, known as Trial Standard Level 4 (TSL4), aim to tighten energy efficiency requirements across all types of EPSs. TSLs are a tool used by the DOE to set energy conservation benchmarks.

Whatever the reason you are purchasing a power station, the most important spec to pay attention to is watt hours, which is a measurement of how much energy the power station can hold. While a particular power station might claim to hold 1,000 watt hours, the actual amount of usable power you can get out of it is a different story.

The answer to this depends largely on what you intended to do with it. If all you want is backup power for your family's phones while camping over the weekend, you can get away with something relatively small — 200 watt hours would be more than enough.

To help you decide, I tested the efficiency, in a variety of scenarios, of the best portable power stations from Jackery, Oupes, EcoFlow, Anker, Goal Zero, Grecell, Bluetti, Dakota Lithium, Lion Energy, Vtoman, and Oupes. ↓ Jump to the Rest of the Field ↓ What to Know Before Purchasing a Portable Power Station

Bring big backup power with you with these expert-recommended portable power stations, which can store enough power to charge electronics, appliances, and more.

If all you have is a basic wattage number, say for a light bulb, typically that can serve as the watt hour number. For instance, if you are trying to power a 40-watt light bulb for one hour, it will use 40 watt hours. When choosing the right portable power station size for your needs, tack about 30 percent on to account for power loss while in use.