7x Solar -How many Lux hours to add 1 % to battery charge?

Well, there is no reason to take a review from DC siously. It's just commerial talk for its own benefit 

Do you live in iraq or just traveling there?

I'm in iraq too (Kurdistan) it's hard to get Garmin products inside county it's prohibited by the airport.

Checkout www.pocketnavigation.de/.../ for a very detailed solar test on the 6x (in German). The numbers match Garmins numbers: 0.25% at 50k lux but it can go higher to 1% if it's much brighter. That is with the watch turned off.

The 7x in theory (using Garmins numbers) should reach 0.3% at 50k lux. You could try that with watch turned off for few hours (anything less may not give accurate results) and making sure the watch is not too full (below 80% or so). In battery saver mode and 50k lux it would need about 4 hours to run forever (or 1 hour under right conditions).

In GPS mode it will drain 1.1% per hour so in that mode it's just for extending battery life.

This is what my uderstanding is:

In Garmin Specs for 7XSS they say: Smartwatch: Up to 28 days/37 days with solar*

By Smartwatch mode I can understand HR ON, Notifications and connectivity with Smartphone at least. 

If 28 days = 100% battery capacity, we should be able to increase 9 days, that is 32% more battery. 

They say this 32% of the battery is achievable from 150k LxH per day, so 32% / 9 days = 3,55% should be from 150 LxH ( when we talk about smartwatch use)

In this case, when normally without Sun, watch should consume 3,57% / day, after exposing to Sun and gaining 150k LxH, it should consume almost zero % (0,02%)  battery in Smartwatch mode.

I would translate that calculations into below % of the energy increase:

1% is 42.3k LxH

then

1k LxH = 0,024%

10k LxH = 0,236%

25k LxH = 0,591%

50k LxH = 1,182%

100k LxH = 2,364%

150k LxH = 3,546%

250k LxH = 5,910%

500k LxH = 11,820%

That is purely from specification that we can see, basing on Smartwatch usage only scenario, so it should have unlimited energy when exposing to sun and achieving 160k Lux daily.

That 32% is gained over all 37 days, so 150 Lux per day would be 0.87% per 150 Lux. So to answer OPs question, 173 Lux should net you 1% more battery.

My 7x will arrive Wednesday I'll test solar charging as soon as i got it

esselite said:

They say this 32% of the battery is achievable from 150k LxH per day, so 32% / 9 days = 3,55% should be from 150 LxH ( when we talk about smartwatch use)

I think at this point there is a bug in the calculation. The 32% are correct, but it must be divided by 37 days not only 9 days, because the 150k LxH per day are needed every day of the complete cycle.

So if turned off, the watch should gain ca. 0,86% per 150k LxH, turns out to need 173k LxH to gain 1%.

Yeah you're right

But if you schedule battery saving for night and turn off Bluetooth it'll last maybe 40 to 50 days so it needs less Lux/hour per day or to maintain current charge

I'm here with work.

Managed 329k Lux today with watch in battery saver mode with everything turned off. Battery level didn't change.