For our final project, the solar panel receives the photon which is the solar energy from the sun and then converts them to electrical energy ( maximum for 22 v). For the first time, our solar panels just can provide a maximum of 14 v electrical energy, but after some trials, we found that 14 or lower than 14 v cannot provide sufficient energy for the lithium storage battery. So, we changed to bigger solar panels. Then we found that the capacity and power rate of lithium batteries were too low. We switched to lead-acid batteries, which have more storage capacity and faster power. In order to make it more convenient to use, we add a power indicator between the solar panels and lead-acid batteries. It shows how much power is left in lead-acid batteries and how much power is being provided by the solar panels.

The whole process is that a 20V solar panel receives photon from the sun and converts it into electricity of about 20V. At this time, there are two circuits to choose from. When we open the Power Switch, the electric energy converted by the solar panel will flow directly to the safe step-down USB interface, which can directly charge the mobile phone. When we turn off the power switch, the electricity will flow into the lead-acid battery for storage. The lead-acid storage battery is connected to another power switch and a safe step-down USB port. When we turn this switch on, the power in the lead-acid storage battery is sent to USB to charge the phone.

We have successfully applied energy conversion, converting solar energy into electricity. Then the electrical energy was successfully stored. Eventually, our solar charging bank can be used in a variety of situations. When the sun shines brightly enough that the phone does not need to be charged, the solar energy transfers electricity to and stores it in lead-acid batteries. When the sun is shining brightly and the phone needs to be charged, the solar panel can also charge the phone directly. When solar power is not available but the phone needs to be charged, such as at night and on cloudy days, the electricity stored in the lead-acid battery can be used to charge the phone. When the sun is shining or the lead-acid battery is fully charged, the device can provide a one-hundredth of a minute’s charge. This kind of charging efficiency is very high, surpassing most charge banks.

We can improve the portability and appearance of the product so that customers can use it more conveniently. Attract more customers through better appearance. But the side effect of this is that it becomes less efficient to charge because we reduce the size of the device

This device is very environmentally friendly. It uses renewable energy to charge mobile phones. Solar is a renewable energy source that is environmentally friendly compared to non-renewable sources such as burning coal to generate electricity It consists mainly of a solar panel and a lead-acid storage battery, and the battery can be reused and does not need to be replaced often. Changing batteries frequently is bad for the environment because many people don’t know how to properly dispose of discarded batteries. If they throw the waste battery directly into the trash can, it will cause great environmental pollution. This battery eliminates this problem by replacing disposable batteries with reusable lead-acid batteries.

Our customers are mainly those who are camping in the wilderness or driving tourists. Because they are in a unique situation and do not have the mobile power service provided by the hotel, using this device ensures that they can continue to use the phone in such a situation.  We also hope that more customers can use this device in their daily life so that they can have the concept of renewable energy use. We hope that this product is not only a charging bank

but also can promote more people to use renewable energy to protect the environment. The earth’s resources are limited, and we need to cherish them so that we have sufficient reserves in special circumstances.

 

 

 

As you can see in these pictures and videos, the percentage of the phone’s battery is increasing by the time.