This Lithium Charger Module is made for charging rechargeable lithium batteries using the constant-current/constant-voltage (CC/CV) charging method.

In addition to safely charging a lithium battery, the module also provides the necessary protection required by lithium batteries.

The Lithium Charger Module uses the TP4056 Li-Ion charge controller IC and a separate protection IC. There are other types of modules on the market that use the TP4056 but lack any protection circuits to provide the necessary protection needed with lithium batteries. Modules with protective features can be recognized by the chips soldered to the board: There are 2 additional chips beside the TP4056 charging controller; the DW01A Li-Ion battery protection IC, and the dual power MOSFET battery disconnect switch 8205A.

This setup provides the following features:

• Manage the constant current to constant voltage charging of a connected lithium battery
• Over-discharge protection - keeps your battery from being discharged below 2.4V, a healthy minimum voltage level for your battery. If a connected battery has been discharged below 2.4V the module will cut output power from the battery until the battery voltage has been re-charged above 3.0V (the over-discharge release voltage), which at that time the module will again allow discharge of power from the battery to a connected load. Although the module cuts output power from the battery during an over-discharge situation, it still allows charging of the battery to occur through the parasitic diode of the discharge control MOSFET (FS8205A Dual MOSFET).
• Overcharge protection - the module will safely charge your battery to 4.2V
• Overcurrent and short-circuit protection - the module will cut the output from the battery if the discharge rate exceeds 3A or if a short-circuit condition occurs
• Soft-start protection limits inrush current
• Trickle charge (battery reconditioning) - if the voltage level of the connected battery is less than 2.9V, the module will use a trickle charge current of 130mA until the battery voltage reaches 2.9V, at which point the charge current will be linearly increased to the configured charge current.

The Lithium Charger Module can be powered by a micro USB cable or the IN+ and IN- connections. The power source needs to be able to provide at least 1A for the charger to correctly charge a connected battery. Most modern phone/USB chargers can provide 1A or more; refer to the label on your phone charger to verify. If you use the micro USB connection, be sure to use a USB cable that is made to carry at least 1A. Furthermore, the board includes two indicator LEDs to indicate charging and charge termination (complete). The charge current is preset to 1A, which is optimum to safely charge batteries with capacities of 1.4 to 5 Ah. The Lithium Charger Module itself needs only some micro amps whenever it is connected to a battery. It is fine to leave the battery connected for long periods, but it can drain the battery after a couple of months. We recommend disconnecting the module from the battery when not in use for several months. It is possible to connect two lithium battery cells of the same type in parallel to form an equivalent single-cell battery with a total capacity of twice that of the individual single cells, but we do not recommend connecting more than two cells at a time to this module. Only balanced cells of the exact same type and production batch should be used for a connection in parallel.