Review on 🚗 ZYTC Quick Charge 3.0 Car Charger: Waterproof Dual QC3.0 USB Fast Charger for Marine, Boat, Motorcycle, Truck, Golf Cart - 36W Aluminum Black with Red LED Digital Voltmeter by Andrew Kamkoff

I had serious questions that were not fully answered in the description. So before I started cutting holes I thought of doing some dyno testing. Here are my results. This assumes you have the fuse connected and going straight to the battery (non-switchable solution).1. The voltmeter is accurate. It's not as fast as my good bench meters, but they do when curves are accounted for. 14.48 on a good meter = 14.5 on a USB charger, for example.2. I then connected it in series to draw current. When the switch is off, the current draw is 0.00A and the voltage indicator is off. When the switch is on (and no USB) there is a tiny indecisiveness. Conclusion = DO NOT LEAVE THIS ON WHEN PARKING YOUR CAR. After a while, this can lead to the discharge of the battery.3. The USB port will ONLY CHARGE when the switch is on. When the switch is off, it does not pass any voltage. The switch must be on to charge. Opinion: For a hobby or small farming application, that's perfectly fine. ATVs, SideXSides, etc. If you want to install it on a machine that you think is like a road bike or car, I highly recommend using a switched-source relay (something that only activates when the key is turned on). You use this relay to power the fused circuit that controls this adapter. And if it's on a motorcycle, you better think about the pollution! I recommend these parts: RELAY - https://www.amazon.com/ONLINE-LED-STORE-Waterproof-Harness/dp/B01N66W2XFFUSE - https://www.amazon.com/MUYI-Inline-Holder-Waterproof-Pigtail /dp/B07G7YMJXWSealant - (after using the appropriate connectors) https://www.amazon.com/Proxicast-Pro-Grade-Weatherproof-Self-Fusing-Electrical/dp/ B00K5GW67O Hope this helps people.