General brands of universal charge are very safe. For example, the pivoFUL universal charger has a built-in high-performance switching power supply with a wide voltage adaptation range of 110-220V AC. And it uses a microcomputer chip to control the charging process, fast, high efficiency, automatic shutdown when full, safe and reliable; The other type is lightweight, easy to carry and easy to operate; The most important is the intelligent recognition circuit built into the universal charger, which can automatically convert the charger output polarity to adapt to the positive and negative battery poles. Comprehensive protection of battery safety during charging.