Review on 🔌 Upgraded Version: Quick Charge 3.0 Dual 12V USB Car Charger with Digital Voltmeter - Waterproof & Power Switch Button for Marine Boat, Motorcycle, Truck, Golf Cart, and More by Jon Ford

I installed this in an RV. I like that there is an on/off button. I tested it on two different Android phones version 2.1. QC must be backward compatible. It's painfully slow to load. Starting with a 25% charged phone, it took 9 hours to charge to 70%. Then finally up to 100% only after charging overnight. The voltmeter reads slightly higher. Pretty easy to install, but slightly larger than a 1" hole (odd size). A good concept would be much happier if it charged my phone in a reasonable amount of time (less than 8 hours).