5V 2.1A Power Bank Charger Module Power Bank Circuit Board PCB Step Up Boost Power Bank Module DIY 18650 Battery for Xiaomi

Output: DC5V/2A max, input DC5V/1A, for Android line interface   Battery voltage: 3.7-4.2 lithium battery   Note: the battery must be in parallel rather than in series. Test voltage before installation. One bad battery will affect the whole group battery. Recognize the positive and negative. If you put them in the wrong position, mainboard IC will definitely be destroyed. To avoid damaging the motherboard, exposed part of the wiring must be wraped well   B- Negative  B+Positive   Size: 7.1x1.6cm/2.80x0.63inch Quantity: 1 Pc Note: Please allow 1-3mm error due to manual measurement. pls make sure you do not mind before you bid Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you!   Package Contents: 1 Pc x Power Bank Charger Module