Approximately 8 hours. A 10V40W solar panel can charge a maximum of 4 amps of lithium battery per hour. A typical cell phone battery has a capacity of 32,000 mah, which can be fully charged in eight hours. Since the lithium battery voltage is 4.8-5V when charging, the voltage needs to be converted, and the efficiency is generally around 70%. Then this solar energy can only fill a 20,000mah power bank in one day.
Becausethe actual charging efficiency of solar panelsis not high.
A foldable solar panel with an output voltage of 5 V and a power of 10 W (the surface area of the solar panel is equivalent to the size of two iPads) is placed on the balcony of your house. In good weather, it takes about a week to fully charge the Xiaomi 10400mAh power bank, so the efficiency of cactual load of the solar panel is not high.
Relevant information is as follows
If a solar cell is designed on the back cover of a mobile phone, it can theoretically be used to charge the mobile phone. However, on the back cover of a mobile phone, it can theoretically be used to charge the mobile phone. On the one hand, the small area of the back cover of the mobile phone determines its charging efficiency. Capacity is very limited. On the other hand, solar panels have almost zero output voltage and current when faced with indoor fluorescent lights, LED lights and other artificial light sources, which also limits the applicable scenarios for solar charging.
The history of solar-powered cell phones is interesting, but because there are few breakthroughs, it seems very boring.
Samsung was the first fabricant to market a mobile phone powered by solar energy, in 2009. This model, called "Solar Guru", was mainly sold on the Indian market to cope with the frequent large-scale power cuts that India was experiencing at that time. era. However, due to limited technology, the solar charging efficiency of this machine is terrible. It takes 1 hour to charge and 10 minutes to talk.