Look closely at the board. You’ll see a tiny jumper connecting JD-Vcc to Vcc. The manual eludes to this with a cryptic sentence like, "If use different voltage, take out jumper."

This is where the XH-M608 becomes a magician. Leave the jumper on: the relay coil and the logic circuit share the same 5V power – simple, for beginners.

Remove the jumper: You can now power the relay coils with 5V (or 12V, or 24V!) while your microcontroller uses 3.3V. This is complete isolation. It means your $50 Arduino won’t fry when the water pump kicks in. The manual doesn’t explain why this is glorious – but trust me, it’s the difference between a hobby and a house fire.

Once powered, the screen will light up. Here is how to program your weld time.

The board has two user-set voltage thresholds:

| Parameter | Display Code | Function | |-----------|--------------|----------| | Start Voltage (Low cutoff) | P1 | When battery voltage drops to this value, relay activates (starts charging). | | Stop Voltage (Full charge) | P2 | When battery voltage rises to this value, relay deactivates (stops charging). |

To follow this XH-M608 manual effectively, you must identify the physical components on the board.

Safety Note from the Manual: The trigger terminals carry a low-voltage logic signal (5V). Do not apply mains voltage to these terminals.

The Xh-m608 Manual is not a single authoritative document but a collection of minimal factory inserts, community-written guides, and generic PID controller instructions. It is essential for configuring temperature setpoints, hysteresis, and heating/cooling modes, but often lacks critical details like sensor beta values, error codes, and safe wiring practices.

Final takeaway:

Always test the controller with a low-power load first, use an external fuse, and refer to online tutorials to fill the gaps left by the original manual.

| Problem | Likely Cause | Solution | |---------|--------------|----------| | Display shows --- | No battery connected or voltage < 10V | Check battery voltage and wiring | | Relay chatters | Loose connection or insufficient current | Tighten terminals; ensure battery > 9V | | Does not stop charging | P2 set too high or charger voltage never reaches P2 | Lower P2 or adjust charger output | | Stops charging immediately | P1 and P2 too close | Increase difference (e.g., 12.0V / 14.0V) |

To avoid frustration, follow this workflow:

Xh-m608 Manual