My 830 battery is at 37% after approx 10 hours of logged rides. Thats with a fair bit of non-ride messing about as it's a new unit. Most of the rides have been with Varia Radar in relatively heavy traffic keeping the screen backlight on a lot and making a lot of noise. Sensors are HR, Speed, Cadence, Di2, ANT+ lights and radar, with occasional powermeter, depending on the bike.
Screen is set to auto and off after 15 seconds and using GPS/Glonass.
I think this is a tough setup for the 830 due to the Varia, and without it I'd be expecting at least 20 hours of battery.
I've had zero issues so far with the device and because of all the new features and better speed I'm using it instead of my 1030.
jgforrestthat's a great news about the 830, I was considering getting the 1030 intead of the faulty 820, but I'm not any longer, all the latest feedback on performance of 830 mske me pretty certain about the choice; battery life is most significant issue but better speed in comparison to 1030 make it even better