MINI USB input terminal with a female, can be directly input to do with the phone charger rechargeable lithium battery, and still retains the input voltage wiring pads, can be very convenient DIY. This module is used for single-cell lithium or lithium multi-section parallel, charging ports can take power from USB. Input Voltage: 5V Full charging voltage: 4.2V Max output current: 1A Material:metal Colour:blue Power Indicator: Red stands for charging, Green stands for fullly charged. Input interface: MINI interface Item Size: 25mm*19mm. It can be used for voltage 3.6 3.7V, etc. 18650, polymer and other lithium battery charge and discharge protection. Instructions / Precautions: Test current meter in series with the charge sheet only 5V input. Charge current is best battery capacity 0.37C, is 0.37 times the capacity, such 1000mAH battery charging current 400 this is enough. The effect of excessive charging speed backward, rushed over battery voltage out on much Not too small and too long charging connector wires. Such big connection resistance. Too thin, then rushed over battery voltage out on much. Connected to the battery the best good contact. Otherwise rushed over battery voltage out on much. If the 5V input voltage is high, such as 5.2 or even 5.5, will result in insufficient charging current is 1000mA, this is normal. High voltage chip fever will automatically reduce the charging current, not to chip burned. Chip at work about 60 degrees fever is normal. After the charging current is large. Enter the reverse has no effect on the chip, but the output (battery terminals) reverse will burn the chip, please note that buyers. Package includes: 5x Charger Module Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.