Reserve Strap to Offer 30 Hours of Extra Apple Watch Battery Life, Launching in November

[Wannabe Actuary]

I'm not having any issues with battery life either. I take it off around 9 PM, let it charge for an hour and put it back on before bed. I've never run out of battery charge and I've had it on during several 1 hour+ cycling rides (which are supposed to drain the battery doing heart rate checks).

Typical use I've had no issues, but try running a marathon...
I just ran my first last weekend and the watch died about 4:15 into the race for me. As you mention, starting a workout tracks your heart rate constantly and kills battery.

I love the concept of this band, but for the 2-3 marathons I plan to run each year I'm not sure it's worth it.