purely mathematically, 7% in 18 minutes = 100% in 257 minutes, a bit over 4 hours, which means that probably you are listening a little louder than they did in their tests (or they had for example less signal interference) but it could be also 6,5% in 19 minutes (we wouldn't know because the info isn't accurate enough to disprove it), which would give 292 minutes, almost exactly 5 hours anyway, it seems like your phone battery discharges faster anyway :P

So, when it comes to the Samsung Galaxy Buds2 Pro, the battery life is pretty good for most daily activities. According to what the manufacturer says, if you're using Active Noise Cancellation (ANC), you get about 5 hours of continuous playback. Turn off the ANC, and you can stretch that to around 8 hours. Plus, with the charging case, you get an extra boost—up to 18 more hours with ANC and up to 21 hours without. Overall, this means you're looking at a total of roughly 23 hours with ANC on, and up to 29 hours with it off from case and buds combined. Our research shows that these estimates are generally spot-on, but keep in mind that battery life can fluctuate. It all depends on how loud you listen to your music and which features you're using. People who often use extras like Ambient Sound or have long phone calls might find the battery drains a bit quicker. Conversely, if you just need them for your commute or a gym session, you’re probably not going to run into any charging issues. For those who are always out and about, having the charging case close by is super handy. Just plop the buds back in during short breaks to keep them juiced up and ready to go whenever you need them.

turn off voice detected if enabled. really improved mine

I do this sometimes to sleep with them on and they last a decent amount longer than when audio is playing. I guess it technically counts as standby time? for context I'll typically get ~7.5 hours of sleep a night and I'll wear them to sleep but they'll usually fall out at some point at night. usually in the mornings they're somewhere around 50% battery left. my guess would be you'd be able to comfortably get 7+ hours if not more while doing this. ymmv obviously but thought I'd share my somewhat similar anecdote