Question about Goal Zero Boulder 100 Briefcase

in June, i.e. at the highest position of the sun, in Ticino, the panel delivers about 75W according to the Yeti400 display. But that is a maximum output. Usually it is around 50W. In summer, the Yeti400 needs about two good sunny days (including reorienting the panel three times every day) from 20% to 100%. During this time, additional connected devices can be charged, as the panel delivers more than the Yeti400 can charge at midday. I don't know if this is also the case with the Yeti1500.

This panel is too small for the Yeti1500. I would buy at least one 200W panel (possibly from another manufacturer), better still two 200W panels. With 400W, the Yeti should be fully charged in about the same time, i.e. within two days.

Tip: Do not discharge the battery below 20%. There are more modern batteries, e.g. from Jackery, which have the 20% reserve already integrated internally, i.e. you can discharge it to 0% while it still has 20% capacity. This serves to protect against deep discharge, which lithium batteries do not like.

I would recommend a 200 watt and I am very satisfied with it. I also have a 1500 x and it was too tight with 100 watts, but now it fits perfectly.

But you should think about how much of the battery you use. 230 watt lamps, mobile phone, fridge balance out my Boulder 100 during the day.