The rear of the meter has a screw terminal block for the four connections (B+, B‑, I+, I‑). No soldering is required; stranded or solid wire up to 1.5 mm² (16 AWG) can be clamped directly into the screw terminals.
Locate the UART communication lines running between the analog front-end chip and the main microcontroller.
(30 AWG) directly to the TX and RX pads.
Disclaimer: This patched manual is based on reverse engineering and community testing. Peacefair has not endorsed these corrections. Always work with DC circuits safely – use fuses and appropriate PPE.
If you are measuring a low-voltage battery (e.g., a single 3.7V Li-ion cell), you must supply an independent 6.5V–100V DC external power supply to power the meter backlight and logic board.
PZEM-051 DC Digital Multi-Function Meter - Instruction Manual
Swap the TX and RX wires. Remember that the transmitter pin of the Peacefair board must connect to the receiver pin of your microcontroller.
It states the device can work with a direct connection up to 10A. This is false. The PZEM-051 requires an external 75mV shunt for any current measurement above 1A. Connecting high current directly will destroy the unit.
Stores energy data and backlight status during power loss. The "Patched" Operating Manual
PZEM-051 DC Digital Multi-Function Meter - Instruction Manual
The PZEM‑051 is a high‑precision DC digital multifunction meter manufactured by Peacefair (and also sold under generic branding). It is designed for indoor use and simultaneously measures and displays four key electrical parameters:
is a popular, budget-friendly DC digital multifunction power meter used by DIY enthusiasts to monitor voltage, current, power, and energy consumption in solar setups, battery banks, and custom power supplies . However, the official documentation often leaves users stranded due to poor translations, missing wiring configurations, or unexplained firmware quirks.