Chosen Solution

I’m about to replace a battery for a client who lives out of town. In the past, I’ve replaced batteries that started malfunctioning within a couple days, but since this client can’t easily come back for a replacement, I want to make 100% sure the battery’s good before sending them on their way. My plan is currently to plug in a battery, turn on the device, use the Battery Life app and do a stress test with video streaming. If it passes the tests, is this enough to be sure the battery is good? Are there any other tests that can make sure this battery won’t start acting up in a couple days? Thanks.

Your testing sounds solid. However, batteries are a curious beast due to their chemical nature. The best way to insure you have good batteries is to stick with quality suppliers. If you have had issues in the past with a certain supplier, you may want to reconsider things and find one who has a very high quality rate.