Diagnosing Power Problems With Batteries vs Power Supply?

I have a Kaisi battery activation and charging board to keep batteries topped off but what if I use a battery to diagnose a shorted board that could compromise the battery making it less useful to diagnose the next phone or potentially short a phone without a short to begin with…right? I realized for the price of not even a few batteries I can but a universal breakout cable for a DC power supply and do it that way, then buy a DC power supply of course. I have a USB multimeter but this way I could actually see the meter readout while on battery power. Any recommendations on what to look for or stay away from when buying an entry level DC power supply or breakout cables??

Thanks!