Battery charge, rapid drain, recharge

Is it winter there? My VA3 (and lots of other electronic gadgets) also have problems with incorrect battery status but this is due to the under freezing temperatures. Yesterday battery was reporting 3% (outside it was -2C) and after some minutes indoor it went back up to 8% even if I did not charge. Not much we can do about it, Lithium batteries do not like the cold.

Also be aware that in most cases, this rapid "drain" is a actually not a battery drain but just inaccurate readings on the battery voltage sensor. Maybe it goes down 5% very fast, but then it stabilises and the actual battery time will be the same.

Finally you don't need to charge up to 100%. It's actually better for the battery health to charge just under the peak capacity, around 95%, and don't let it always go all the way down to close to 0% - once it's below 50% you should recharge if possible. For the VA3 specifically, I usually put in on the charger daily while I shower. If I forget one day or another, no bid deal, as the capacity is big enough and it does charge relatively fast.

Some more info & tips: https://batteryuniversity.com/learn/article/charging_lithium_ion_batteries

You might be onto something here, although in my case it's not the cold but the opposite. The battery charges very quickly therefore it heats up. I presume this will have the opposite of a cold battery and gave it a false full charge. As the battery cools down, it's charge drops and gives us that big battery drop. Explains why another recharge would top it up. The battery doesn't have time to heat up as much.

You are correct, the battery drain is higher on 5.70 than on 5.50. On 5.50 it was 0.4% - 0.5% /hour. On 5.70 it is 0.7% - 0.8% / hour. Calculated on "My battery" app.

You cannot compare the battery drain right after unplugging the watch with the real drain.
I often charge the watch on my computer. This always results in 6-8% drain after a couple of minutes. From then on, it takes 10-20% a day, due to my activities.

To prevent the watch from doing that, it seems to help by

• using a wall plug
  
• load the watch turned off
  

Since I've had this watch I've had to charge to 100%, wait a few minutes for rapid battery drain and plug the watch back in to reach 100% again.

This is exactly my procedure to avoid battery drain but I discovered that after the first charge, if, during the 2nd cycle, I leave the device in charge one or two hours more after the indication of 100% charge, the device is normally working and no additional recharge cycle is requested. The battery last about 8 days without GPS (0.4-0.5 %/hr)

By leaving the battery plugged in for another hour or two, you leave time for the battery to cool down and top up its charge. It does look like the issue is the battery being warm when charging and with the opposite effect of a cold battery (ie, capacity drops fast while the battery is cold) hence the watch thinks the battery is at 100%. Once you unplug and the battery cools down, it's real charge is revealed and we see that big drop in charge.

After 4 days and 3 GPS runs, it was more than 40% left of battery charge with 5.70.

I'm not seeing the issue with 5.70; in fact I'm getting markedly better overall battery life (not sure about 5.90 yet, for obvious reasons).

However, I really think Garmin ought to fix their "bug", which causes the immediate drop, when unplugged from whatever charging source.
This is a problem with pretty much any device with a battery that heats, at all, as it charges, but there are known algorithms for "covering" this (it involves cache-ing the initial, and watching the voltage over that first hour or so, and then "smoothing out" the "false drop").
Garmin has other devices that don't do this (for example, I have a car GPS that does not exhibit it), but for some reason they don't want to fix this on the VA3 (perhaps is prevalent across all their fitness watches, I didn't research that part).

The way it is now, it sort of "cheapens" the experience, if you ask me, like a super-budget phone or similar, which isn't the market-segment for the VA3, as far as I know...

I get that you can do the charge-cool-charge cycle, to "work around" the issue, but it's cheesy; mostly because you're really not adding much charge in that cycle, you're just "fixing the charging algorithm's inability to track it". Why they would let this persist is beyond me (coming for a s/w engineering background).