For drone building and racing, the best bench power supply is usually the one that matches the kind of work you actually do, not the biggest or fanciest one on the shelf. If you build 5-inch racing quads, test ESCs, power flight controllers, or run smoke-stopper checks, a supply with adjustable voltage, decent current limit control, and reliable protection is worth far more than a high-wattage unit with vague specs.
For most FPV bench work, I would look at a supply that can do 0 to 30 volts and at least 5 to 10 amps. That covers the common needs of 2S through 6S gear, small electronics, and troubleshooting. If you only ever power a flight controller or receiver, even 5 amps can be enough. If you want to spin motors on the bench, test several components at once, or run more demanding accessories, 10 amps gives you more breathing room. More current is not a problem as long as the supply lets you limit it properly. In fact, adjustable current limit is one of the most useful features because it can save your electronics when something is shorted or wired wrong.
Look for clean, stable output and a display that is easy to read. You do not need lab-grade perfection, but you do want something that does not wildly jump around when the load changes. Ripple matters more if you are powering sensitive gear or doing signal-related testing. For general drone work, protection features matter more than chasing the lowest ripple number. Over-current, over-voltage, and short-circuit protection are the basics. A supply with a good fan and solid thermal management is also important if you expect it to run for long periods.
One mistake people make is buying a supply that is too weak in voltage. A 12-volt-only unit is limiting if you work with 4S or 6S systems. Another mistake is assuming the highest current rating means it is the best choice. A cheap 30-amp supply may be fine on paper, but if the voltage regulation is poor, the terminals are flimsy, or the protections are unreliable, it can become frustrating or unsafe. Also, avoid using a bench supply to power a full quad at max throttle for long periods unless you know exactly what the current draw is. Bench supplies are better for testing and diagnosis than for replacing a LiPo in normal flight use.
If you are on a tighter budget, a used server power supply with a breakout board is popular in the drone world, but it is not as convenient as a proper adjustable bench supply. It can be a good option for charging or high-current 12-volt work, but you give up some control and ease of use. For a first purchase, I would usually choose a conventional adjustable supply with current limiting, rather than trying to save a little money and losing flexibility.
