In this recent post, https://the5krunner.com/2016/08/05/navigation-fest-edge-820-and-others-do-9-hours-of-trail-navigation/, I managed to get about 8 hours of battery using turn-by-turn (TBT) navigation – GPS+GLONASS, HRV/per-second recording, HRM and a PM. It lasted between 7.5 or 8.5 hours.
I tried a VERY similar route again today (near identical). This time I managed only 6 hours of battery. The only material difference was that the HRM was the STRYD (HRV) and I knew the route very well and made virtually no wrong turns. So you would have thought it would have lasted longer? Especially as I turned off quite a few of the myriad of other sensors I have paired to the 820 (firmware v3.10).
well 6 hours is a LITTLE unfair. That was the point at which it said the battery was nearly out. As I had stopped anyway at that point I though it was a good time to turn another device on for replacement navigation. it transpired that there was 9% of the 820’s battery left…say a generous half an hour??? Still that 6.5 hours vs 8ish last time.
This time though the 820 was good on the NAV front and I had no lock up or reboots. The screen WAS SLOW sometimes re-displaying the map but fine for the purposes of today.
When the 820 is sweet. It’s real sweet. I do like it.