When we tested our solar panel chargers with our phones they did not charge. We realized that our batteries were not strong enough to charge our phones. With further research we saw that we needed 5V of energy in order to charge a phone. Since both of the batteries we had were 1.2V we only had 2.4V of energy, which was not sufficient enough to charge a phone. We then ordered 3.7V rechargeable batteries, but they were the wrong size and could not fit in our AA battery holders. we tested our solar chargers again but with our original 1.2V AA batteries and we used a USB charger and LED. When we plugged the USB in the LED glowed but was very dim. We concluded that we had the right concept but we just did not have the right materials to successfully charge a phone.
This relates to engineering because we had to come up with possible solutions to our problems and we had to go through the engineering process with succeeding and failing to make a product. Our original batteries did not work so we had to decide what type of batteries to get.