Thank you for bringing this concern to our attention. I understand that you may be disappointed with the solar panel's output. It's important to note that solar panels do have inherent losses due to various factors such as temperature, shading, and efficiency. These losses can account for approximately 20%-30% of the rated capacity.
And solar panel is indeed influenced by various factors, such as environmental conditions, sunlight intensity, solar elevation angle, and shading, among others. As a result, achieving exactly 100% of the rated capacity might not always be possible. In your case, obtaining 78% of the rated capacity is within the normal range of performance for solar panels.
If you have any further questions or need assistance with your solar panel or any other Jackery product, please don't hesitate to reach out to hello@jackery.com. We are here to help and ensure you have a satisfying experience with our products. Thank you for your understanding, and we appreciate your support of Jackery products.