Solar Charging not working?

I have the same issue. After leaving him at the direct sun for an afternoon, I've got the infinity symbol where the days left should be but the battery still at the same percentage of before. I've contacted Garmin let's see what they say

The charging is not linear. Maybe you also had 96.6% and it charged to 97.5 and it still showed the same. It depends on how your watch is set up. It saves a lot of backlighting the display, I have 5% and the update one minute. I don't know for an hour, but sometimes my watch charges up to 5-6% a day in the sun. Other times only 1%.

They replied me, I'll translate the best I can from Italian:

The watch uses our lens to convert sunlight into energy for the watch battery to give you more autonomy between charges. Solar charging is not designed to serve as a primary energy source or to achieve unlimited battery life.

Besides what TeaRacer said, battery percentage and estimated days of battery life are two different things. The first is absolute, as it indicates how much charge the battery has. The second is relative, as it takes into account the battery charge AND the power consumption of the watch, and it is recalculated constantly.

When you leave the watch in the sun, given a certain battery charge percentage, the power consumption depends on how you have set the watch and how much of its circuits go to sleep. For example, not wearing the watch the HR sensor LEDs turn off. The accelerometer and gyroscope are not sensing any movement, therefore they probably go into sleep mode as well. The backlight is not being used, hence more power saving.

You get the infinity icon for number of days left because with the watch being in the sun rather than on your wrist, the power it consumes is compensated by the charge it receives through the solar panel, and therefore it could literally go on forever.

You have excellent points there.

Makes sense that if the watch is just sitting under the sun it will charge more than it being on your wrist.

Maybe using it on the wrist will take longer to get 1% under sunlight.

Yesterday I was outdoors under the sun for like 2 hours, it barely got 1%. Went from 97% to 98% for 5 minutes, before it went down to 97% again.

Today I tested it again, but I put it on my car windshield, looks like it got around 1.5% in 2 hours.

Field testing a solar powered device is very difficult. You should do it over several days if not weeks, ideally always for the same duration and during the same time of the day and than average the results. Even with that, from one day to another there might be haze, clouds or simply the normal changes in solar rays angle as the season progresses. Assuming you could have the most controlled conditions possible, it would be purely academic, as you did not buy the watch to keep it charging in the sun all day.

I suggest you do not obsess over this . The Instinct Solar already has longer battery life per charge than the original Instinct, even not taking into account solar charging. Consider that a nice bonus and a way to harvest whatever energy you can in between regular charges. Garmin make it clear that solar charging is not supposed to be the only and main method of charging it.

I still have an ancient Casio WaweCeptor Solar, with mechanical movement and LCD display, that works exclusively with solar power (recharging an internal battery). However, the whole face is a solar panel and not being a smartwatch its power consumption is a small fraction of what a watch like the Solar Instinct need, with a much larger display, multiple sensors, more powerful microprocessor, memory and wireless communication

I think we do not have yet the technology to allow a smartwatch to survive only on solar power (or it would be outrageously expensive at this time)

Indeed. I agree with you. I was just worried since my solar charging was subpar compared to other people with the same model.

And since I'm within the first week of usage, it would be easier to return it.

Today I did another test, but this time I left the watch on my backyard, and it did charge 2% in like 4 hours under full sunlight.

Feels kinda slow compared to other reviews. Idk really...

Btw, do you know if the 24 days of battery claimed by Garmin is the usage of the watch just on smartwatch with 0 daily activities?

I usually workout 6 days a week for around 1 hour per session, does that mean I will be getting way less than 24 days?