The TP4056 is a 2-in-1 USB-C lithium battery charging and protection module — it charges a single-cell 18650 or other Li-ion/LiPo battery while guarding against overcharge and over-discharge, and automatically controls the charging current to protect the cell. With a charge status LED, a USB-C input, and breakout pads for DIY wiring, it's the standard building block for portable and battery-powered projects.
- USB-C input — 4.5V to 5V, up to 1000mA charge current
- Built-in overcharge, over-discharge and over-current protection
- CC-CV charging with soft-start and trickle pre-charge below 2.9V
- Charge cut-off voltage: 4.2V ±1%
- Over-discharge protection: 2.5V / 3A
- Automatic load switching — draws from input when present, battery when not
- Red LED indicator — flashing while charging, solid when full
- OUT terminals supply battery (cell) voltage, not 5V
- Compact 2.8cm × 1.7cm board
- Solder pads for battery (B), load (OUT) and direct 5V input
Specifications
What's in the pack
Quantity as selected. Ready to wire — no additional components required.
Great for
Getting started
- Identify the pads
The USB-C port (and its adjacent +/- pads) is the 5V power input. B+ connects to the lithium battery's positive terminal and B- to negative. OUT+ and OUT- connect to your load, such as a boost converter — note these supply the battery's cell voltage, not 5V.
- Connect the battery first
Solder B+ to the battery's positive terminal and B- to negative, taking care not to reverse them. On first connection with a new cell there may be no output at OUT+/OUT- until you apply 5V via USB-C once — this activates the protection circuit.
- Power via USB-C to charge
Use a plain ("dumb") USB-C cable with a charger or power bank that can output at least 1A. The red LED flashes while charging and turns solid once the battery is full.
- Connect your load
Wire your circuit to OUT+/OUT-; the red LED stays on solid once a load is connected. While USB-C power is present the load draws from the input; when unplugged it draws from the battery automatically. Output cuts off if battery voltage drops below 2.5V.
Common questions
Why is there no output voltage when I first connect the battery?
This is normal. When connecting a new cell, the protection circuit needs to be activated by applying 5V to the USB-C input at least once. After that, the output works normally, drawing from either the input or the battery as needed.
Which USB-C cable and power source should I use?
Use a plain ("dumb") USB-C cable with a USB power supply or power bank rated 1A or greater. This module does not negotiate USB-C power delivery and may not work with "e-marked" Type-C cables, and it does not read the current capability of the source. Avoid powering it from a computer or phone — use a dedicated charger for reliable charging.
What battery types can I use?
The TP4056 is designed for single-cell Li-ion or LiPo batteries, including standard 18650 cells. It is not suitable for multi-cell packs or other battery chemistries such as NiMH or lead-acid.
What happens if the battery over-discharges?
The module automatically cuts off the output when battery voltage drops below 2.5V, protecting the cell from damage. It also limits load current to around 3A to prevent excessive draw.
Can I run a load while charging?
Yes. When USB-C power is connected, the output draws current from the input rather than the battery, allowing simultaneous charging and operation.
Good to know: Connect the battery before first powering the module via USB-C to activate the protection circuit — a new cell may need 5V applied once before the OUT terminals supply power. Use a plain USB-C cable with a charger that outputs at least 1A (not a computer or phone port) for reliable charging. Take care to connect the battery the right way around, and follow standard safe-handling practices for lithium-ion cells.