Review on 🔌 DZS Elec Mini DC 5-36V USB Buck Converter Regulator Power Supply Module - Step Down Voltage Module for 36V 24V 12V to 5V 3A USB Charging by Duane Kaul

This is a nice little USB charger. I bought it with a 12v battery that didn't have a charging connector. I installed it in a small plastic earbud box with a battery input plug. The efficiency of this charger meant that the 12V, 3000mAh battery capacity would provide a measured 5V, 5700mAh output from this charger - two full charges for my phone. I use the 12v battery for other purposes too, but this is a nice extra option. If you haven't bought a battery pack yet, you can find some that already have a built-in USB charger. However, if you also use a battery pack for low noise applications, you may need such a detachable charger to eliminate the switching noise from the battery output when not in use. Good product, worth a few euros more. SUPPLEMENT: I have found that the cable between this charger and my phone affects the charging current. My Samsung Galaxy 4 only charges at 420mA with a long cable, but at 1.5A+ with a short cable. Because the phone recognizes the voltage drop in the cable and limits the charging current. If you want to take advantage of this charger's fast charging feature, make sure you use the shortest, thickest cable between the charger and your phone.