This product is a small voltmeter that can be mounted by two screws. It has a very small error (1%) and has a resolution of 0.1V. It has maximum measured voltage of 30 V and is sufficient for most common applications.

This voltmeter is useful in building your own power source that consists of a power transformer and a power-down switching voltage.

Specifications:

• Voltage measured: 0 – 30V
• Resolution measured voltage: 0.1V
• Voltage: 5V – 30V
• Current consumption: 13mA
• Error: ±1%
• Refresh rate: 300ms
• LED Display 0.36 “
• Impedance: more than 100K
• Display color: blue
• Dimensions: 23 x 15 x 10mm
• Connections: Black – GND; Red – VCC supply; White – measured voltage

Overview

This tiny module is perfect for charging single cell 3.7V 1 Ah or higher LiPo cells such as 16550s that don’t have their own protection circuit.

Based around the TP4056 charger IC and DW01 battery protection IC this module will offer 1A charge current then cut off when finished.

Futhermore when the battery voltage drops below 2.4V the protection IC will switch the load off to protect the cell from running at too low of a
voltage – and also protects against over-voltage and reverse polarity connection (it will usually destroy itself instead of the battery) however
please check you have it connected correctly the first time.
Specifications

Input voltage – 5V via microUSB or solder pads on left-hand side of module
Full charge voltage – 4.2V
Charging current – 1A by default. However you can change this by changing the 1k2 resistor next to the “IN-” pad the bottom-left of the board.
See the Rprog table on page three of the TP4056 data sheet for different values and matching charging currents