Industry-Electronics 4duino 5V 1A Lit-Battery Micro USB Charger mit protection Module OKY3404-1 5V 1A Micro USB Lithium Battery Charging Board Charger Module Product Description 100% Brand New &amp High Quality 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 Input voltage: 5V Charging cut-off voltage: 4.2V ± 1% Maximum charge current: 1000mA Battery over-discharge protection voltage: 2.5V Battery overcurrent protection current: 3A Board size: 2.6 * 1.7CM It can be used for voltage 3.6 3.7V, etc. 18650, polymer and other lithium battery charge and discharge protection, single or multiple parallel