Review on 🔌 YONHAN Motorcycle USB Phone Charger 4.8A with Voltmeter, SAE to USB Adapter and ON/Off Switch, Dual Port Fast Charging 3 Installation Options Waterproof Quick Disconnect Plug for Smart Phone Tablet GPS by Paul Milonas

I received this USB charger as an emergency charger. I use batteries from a Dewalt cordless drill. I simply cut off one end of the fork and crimped the blades. Insert the spade terminals into the battery contacts to turn on the charger. The battery capacity is larger than that of an expensive portable cell phone charger. I didn't have any polarity issues as stated by other reviews. Red is positive, black is negative. I'll use it for a while and see if it drains the battery when it's off and not charging the device, or even when it's on and not charging the device. The digital voltage display on the device simplifies this task. I checked the voltage with a meter and the charge voltage is displayed accurately. So far this item is looking good. Update follows.