How long does solar charging work?

Are you a conspirator?

absolutely not :) I just want to understand if solar products have a very limited lifespan. 
Many consider them too expensive compared to the real advantage they offer in terms of battery 
life, if the efficiency and durability are also limited it might be appropriate to avoid them,
 don't you think?

If you think, don't buy it! .. That's all !

I think that the possibility of using solar charging is still useful, 
otherwise I would not have purchased the Edge 540 solar after the 
Instinct 2 solar. The doubt, given what has happened, is the reliability
 of this function over time. On the Instinct 2 solar post, there are 
currently three of us who have had the malfunction, two immediately
 after the second year and one case after just over a year. 
If no other Garmin solar device has experienced this problem,
 it could be a defect of the first generation Instinct 2, fortunately,
 which however Garmin does not intend to recognize at the moment

At some level residential solar panel efficiency is known to decay over life, perhaps slightly more in the beginning of life vs later.  If I recall, the decay is not really significant (1-2% annually?)

How this may or may not relate to the technology used in Garmin's watches I guess is unknown - but I agree that I wouldn't expect a watch's solar efficiency to decay from a notable and functional level to nearly useless in 2 years.

For what it's worth, I bought an 840 Solar and have mostly been unimpressed by its Solar usefulness since purchase.  Often gaining 10 minutes of ride time over a few hours in the sun.  Still I don't think I've yet noticed any obvious decay in this value (it is highly variable based on ride sunlight, random tree cover, or even shade from my body based on ride direction and sun angle).

Geppy75 said:

I open this post to understand if Garmin's Solar devices have a solar charging capacity limited in time, coincidentally equal to the duration
of the warranty.

If this was the case, why aren't many, many more people complaining about it?

If Garmin actually did such a thing, would it really work to sell replacements?

Geppy75 said:

I'm also asking because I recently purchased an Edge 540 solar and I would like to know if it is destined to stop charging with sunlight when
the two-year warranty expires.

There are a bunch of other solar devices. Again. if this was happening, why aren't many. many more people complaining about it?

Unhinged.

I'm trying to ask if anyone else has had similar problems. Furthermore, as had happened to me, it is possible that others have the same malfunction and have not even noticed it. I only discovered it by chance because I certainly don't check the solar intensity widget every day. In any case at the moment, only after writing these posts, two other forum users have reported the same problem on Instinct 2, it may be that it is limited to this device at this point.

Obviously it's just a hypothesis, three cases don't make a statistic.

Don't you think this forum could be the right place to report a potential problem and discuss it? I don't understand why it bothers so much. If I had an Edge 840 solar I would simply check it out and consider myself lucky if it works properly. If I had a non-solar Edge 840 I would ignore the discussion.

The problem is that your “hypothesis” is nutty. 

You should have left that nonsense out. It’s deranged. 

If it had any chance of being true, you wouldn’t have only heard from 3 people.

3 people doesn’t make it a general problem anyway.

why would it be crazy, isn't there a possibility that faulty components will be installed?
 has this never happened? Before I wrote the Instinct 2 forum post, no one else had reported 
the problem. After I wrote this, two other users noticed the malfunction. 
I repeat, three of us are not making statistics, but nothing takes away from the fact that there 
could be other defective devices and the owners have not noticed but by reading these posts and 
doing a check they could find out. To date, how many times a week have you checked the solar
 charging capacity of your device? After you read this post, if you have a solar device, 
I think you've done a check.

Geppy75 said:

why would it be crazy, isn't there a possibility that faulty components will be installed?

You are suggesting that it was deliberate.

How many solar devices have been sold? 10,000? 100,000? More?

You have (allegedly) 3 examples of failures. The evidence suggests the failures are rare (or that the "vast conspiracy" was poorly executed). If the failures were wide-spread, we would have likely heard about many more than 3.

There wouldn't be much advantage of deliberately designing wide-spread failure. There is no advantage of deliberately having rare failures.

Geppy75 said:

In the post I opened ( forums.garmin.com/.../instinct-2-solar-progressive-worsening-of-solar-intensity- and-solar-charging-capacity )
another user also had the same problem two years after purchase.... planned obsolescence?