Review on 🌞 Himino 20W Waterproof Solar Panel Battery Charger with USB Output Ports - Portable Solar Charger for Car, RV, Boat, Cell Phone & More by Bud Crabtree

In general, the panel can accommodate a mobile phone. In direct sunlight, I was only able to get 0.9 amps by charging a 12V deep cycle battery (about 12W total). The big problem was that the charging power for the battery charging pins was not controlled. So if you think you can only charge a 12V lead-acid car or RV battery, you will need a separate charge controller. I assumed the small USB/charging dock on the back of the panel was the controlled outlet since it was advertised as a 12V charger. Testing the power supply over several days, the panel continued to charge the 12V battery to over 15V. So this is NOT a proper 12v charger - it will ruin most 12v batteries! 12V lead-acid batteries should be charged to no more than 14.8V and then charged to 13.2V for maintenance/service. Otherwise, charging above 14.8V will cause the electrolyte to boil. Not only will this burn out the battery, but the hydrogen gas produced during cooking can be very dangerous! In addition, the charging cables are stupidly short and the sockets are not waterproof! A small USB/charging station is attached to the back. So the mounting plate constantly needs a frame or stand to make room for cables and charging ports.