DualUSB 5V module for 18650 lithium batteries with overload / short circuit protection   Features Designed for DIY power bank: The 18650 battery must be low and the length is 65mm. The pointed battery cannot be used.ÿIf you are using old batteries, with different capacities, the assembled battery is guaranteed for at least 3.5V per voltage. If the voltage is too low, it will not charge.(Note: It also supports lithium battery, mobile phone battery and tablet battery). Supported Connection Methods: Only one lithium battery or several lithium batteries can be connected in parallel. The capacity of the connected battery does not exceed 200,000 mA, as long as a battery with a voltage of 3.0-4.2 V can be used. Note: The cable connected to the battery must be short.  Protection function: the protection circuit of the enhanced lithium battery has been integrated, prevent overcharging, protection from overload short circuit, over current protection and over temperature protection.Note: the positive pole of the battery is connected to B + and the negative pole is connected to B-, do not reverse it.If it is reversed, it will burn !!!! Charging cable: supports charging of three USB data cables, also for iPhone and Android. Size: 6 , 5 * 2.5 * 0.1cm Double output current: 5V 2.4A; Input voltage from B + to B-: 3.0 - 4.2 V. Technical specifications  Weight: 10.8 grams PCM IR: ≤65 mΩ 0 V change allowed: Yes Constant current: 2.4 A. Double output current: 5 V 2.4 A. Input voltage B + to B-: 3.0 - 4.2 V.   Overload protection Detection voltage: 4,20 ± 0,05 V. Release voltage: 4,100 ± 0,05 V. Detection delay time: <200 ms Low battery detection  Detection voltage: 3,0 ± 0,10 V. Release voltage: 3,10 ± 0,10 V. Detection delay time: <100 ms Short-circuit protection Short detection delay: <50 uS Release conditions: trim the load Normal power consumption Normal PCM absorption: max 60uA Current Stanby consumption: max 50uA Working conditions Maximum continuous charge / discharge current: 1.5 / 2.4 A. Working temperature:-5 ~ 45 ℃