1. This product passed strict CE FCC and ROSH tests and certified. Adopts patented technology to solve commonly known security problems of car starter. It means this product can work well in extreme environment. 2. The product supports two ways of recharging. You can charge it with 5V or 12V power supply.It is unique that the product can be charged by laptop. Exclusive charger is not necessary for this product. It's easy to charge it. SECURITY FEATURES: Intelligent protection against short circuits. This product will switch off automatically to protect power supply when short circuit occurs. Patented technology: Intelligent anti-reverse protection. This product will switch off automatically when reverse connection occurs in mistake. Anti-charge protection. When the voltage of car battery is higher than that of our product the product will switch off to avoid reverse charging. Anti-over discharge function.when the remaining power is lower than 10% there will be no power to output. Recharging is necessary. Equalizing charging function. This product has equalizing charging function which charges each battery in balance. No swelling battery. Battery will not swell when outside temperature is about 85'C.