During the past 30 days, finally chosen XTPower® MP-S23000 Solar Powerbank (http://www.amazon.de/XTPower%C2%AE-MP-S23000-Powerbank-mobiler-Solarakku/dp/B00936CPXW)
was able to charge my iPhone 14 times from an average low of 18% to full.
Solar recharge requires 4 days in full sun, which is explained by the banks capacity and its panels wattage.
Makes me confident, to “survive” 7 days w/o power outlet 😉
— posted from my iPhone
Uwe Grunewald 