Another really useful thing to have is a programmable load[1]. It's sort of the inverse of a power supply... it's a power sink that you can control. It's really

Another really useful thing to have is a programmable load[1]. It's sort of the inverse of a power supply... it's a power sink that you can control. It's really handy to dial up a constant current setting and plug in a power supply that is under test, and observe how it behaves. They're good for testing batteries, solar panels, and most power supply related things. One example that I'm familiar with (it's what I use on my bench at home) is the Rigol DL3021A[2]. There are a lot of choices out there though, spanning a wide range of price / capability / power handling points. [1]: https://en.wikipedia.org/wiki/Programmable_load https://en.wikipedia.org/wiki/Programmable_load [2]: https://www.rigolna.com/products/dc-power-loads/dl3000/ https://www.rigolna.com/products/dc-power-loads/dl3000/