Have I created a new form of energy? (Battery goes up!)

After owning almost literally every Garmin running watch over the last 5 years (I did a comparison/review blog and resultant paper a while back), I picked what I hope will stick with me for a while - the Fenix 5S. I appreciate the size ... I recognize it has some quirks (no, I don't think my altimeter is accurate... no, I don't care) but here's one that stumped me.

Twice, after finishing runs, I've checked the battery on my watch and it's said I'm at (e.g.) 45%. Then I shower (with the watch), get ready, check it again as I'm about to head out the door... 47%! And sometimes a few minutes later, it'll be at 48 or 49%. Is this just a calibration issue? It is a new watch, but I set it up as clean (no restore, if that's even function anymore) and have just done standard GPS-based runs.

Any advice? Anyone else had this happen?

0 jim_m_58 over 7 years ago

The battery level will go up if the watch is cold and it warms up. I've seen this on a number of watches where I had watchfaces that would try to detect the watch was being charged by watching the battery level. If I was in my nice AC'd house where it was in the 70's F, and then go outside where is was 100+F. The battery level would often rise a bit.

0 thr4 over 7 years ago

This can be related to temperature. In cold weather, battery performance degrades, after warming it can improve. The battery % algorithm might get fooled by this.

0 James K. Polk over 7 years ago

The battery level will go up if the watch is cold and it warms up. I've seen this on a number of watches where I had watchfaces that would try to detect the watch was being charged by watching the battery level. If I was in my nice AC'd house where it was in the 70's F, and then go outside where is was 100+F. The battery level would often rise a bit.

Huh! Could be that. It's not cold here (50° F) but I suppose my house is warmer than that... Oh well! It's also the first battery cycle so I'm sure there's some calibration stuff, too.

0 jim_m_58 over 7 years ago

If you shower with the watch, remember that it's likely warmer in the shower than your house in general, so you could be looking at a change from 50 to close to 100, as the watch is also getting hit with warm water..