I used this product with the power supply. I work for an international charity and needed a product that would be reliable, durable and able to work in harsh environments. The panel is strong and durable. Charging is fast and you can connect your phone directly to the pad and also charge the battery. I also used the panel on a private cruise in Maine to test before heading overseas. For a small boat, this is very effective. The lugs are very strong and I have often simply hauled the plate into the rigging to charge the batteries at anchor. You don't get the best product for the price.