Interesting. PowerBeats 3 spec sheet says up to 12 hours playback time with the W1 chip, versus 6 hours playback on the PB2. I wouldn't be surprised if the battery capacity is slightly improved but the battery housing on BT earphones are so small I'd be surprised if it was even close to the size of say, Apple Watch. The W1 is definitely paying off on consumption somehow...
How much more battery life does the plus have over the regular 7 in a day to day use?
Per Apple's website
7 vs. 7+
- 3G Talk Time (hrs): 14 / 21
- Standby (days): 10 / 16
- Internet use (3G, hrs): 12 / 13
- Internet use (LTE, hrs): 12 / 13
- Internet use (WiFi, hrs): 14 / 15
- Video (hrs): 13 / 14
- BT Audio (hrs) 40 / 60
Generally speaking there is a noticeable improvement in battery life using the 7+ for everyday life vs. the 7. Although it drives a bigger display / higher resolution, that is outweighed by the amount of extra battery capacity provided.
I think if you just play games on it all day, battery life is going to feel similar because both systems will just hammer the CPU/GPU. But for web browsing, email, typical on the go stuff, capacity is what matters. (Well, that and not blowing up / frying an egg on your hand)