Frequently Asked Questions

1. What is the Projecta PM635 Intelli-GRID Master Charger?
The PM635 is a fully integrated 12 V power management system designed for caravans and motorhomes.

It combines:

• 60 A multi-stage AC battery charger (total charge + supply)
• 45 A MPPT solar charge controller
• 45 A built-in DC-DC vehicle charger
• Starter-battery maintenance charging (up to 3 A)
• Precise battery monitoring (voltage, current, Ah remaining, time remaining)
• Low-voltage battery protection (BLVP / LVD)
• Battery isolation switch
• 15 fused load outputs (categorised)
• Water-pump and hot-water system control support
• Monitoring of up to 4 water tanks
• Built-in Bluetooth master for sensors and the Intelli-GRID app
• Support for Projecta lithium batteries, shunts, inverters, external solar controllers and DC-DC chargers

2. Which displays are compatible with the PM635?

• PMD-BT3C – 3″ Bluetooth display
• PMD-BT4C – 4″ touch Bluetooth display
• PMD-BT7C – 7″ touch Bluetooth display
• PMD-BT10C – 10″ touch Bluetooth display

The display is used to view battery data, control loads and pumps, monitor tank levels, change settings, pair wireless switches and view alarms.

3. Can I control the PM635 using a mobile phone?
Yes. Use the official Intelli-RV GEN2 phone app (Android & iOS) when a compatible Bluetooth display is connected. The app provides full monitoring and control of battery status, charging sources, loads, pumps, tank levels and system alarms.

4. Which charging sources can the PM635 use?

• 230–240 V AC mains
• Solar (PV)
• Vehicle alternator via the built-in 45 A DC-DC charger

Charging priority:

• AC + Solar → both can contribute
• AC + Vehicle → AC has priority
• Solar + Vehicle → both can contribute

5. Which battery types are supported?
Nominal 12 V service batteries only:

• Wet / Flooded lead-acid
• AGM
• GEL
• LiFePO4 (LFP) lithium

Never charge non-rechargeable or frozen batteries. Always match the selected battery type to the installed battery.

6. How do I select the battery type?
Prefer the display or Intelli-GRID app.

DIP-switch settings (Pins 3 & 4) if required:

• WET → 3 ON, 4 ON → Absorption 14.7 V / Float 13.7 V
• LFP → 3 ON, 4 OFF → Absorption 14.2 V / Float 13.5 V
• GEL → 3 OFF, 4 ON → Absorption 14.1 V / Float 13.5 V
• AGM → 3 OFF, 4 OFF → Absorption 14.4 V / Float 13.5 V

The most recent configuration method overrides previous settings.

7. How do I set the charging current?
Prefer display or app. Default rates: ≈ 0.1 C for lead-acid, up to 0.3 C for lithium (subject to battery limits).

DIP-switch settings (Pins 1 & 2):

• Both ON → Lead-acid AC 15 A / Solar 30 A; Lithium 30 A
• 1 ON / 2 OFF → Lead-acid AC 30 A / Solar 45 A; Lithium 45 A
• 1 OFF / 2 ON → Lead-acid AC 45 A / Solar 45 A; Lithium 45 A
• Both OFF → Lead-acid AC 60 A / Solar 45 A; Lithium 45 A

8. What do the PM635 charging stages mean?
Five-stage adaptive algorithm:

1. Soft Start – gentle start when voltage is very low
2. Bulk – maximum current to raise state of charge quickly
3. Absorption – controlled voltage to complete charging
4. Float – maintains 100 % charge
5. Recycle – periodic maintenance during long-term connection

If a new AC or solar source appears while in Float, the charger returns to Bulk.

9. What do the CHG LED indications mean?

• Solid ON → Float stage
• Slow flash (1× per second) → Bulk, Absorption or DC-DC charging
• Quick flash (2× per second) → Battery discharging
• OFF → Service battery disconnected

10. Does the PM635 charge the vehicle starter battery?
Yes. Up to ≈ 3 A float/maintenance charge from AC or solar. Starts after 30 minutes if starter battery < 12.4 V and stops at 12.8 V.

11. How does the built-in DC-DC vehicle charger operate?
45 A continuous intelligent charger.
Without D+: starts at starter battery ≥ 13.2 V (4 s), stops below 12.8 V (5 s).
Service battery must be > 10.5 V or starter > 12.0 V.

12. Is the PM635 suitable for vehicles with smart alternators?
Yes, when the D+ ignition signal is correctly connected.

13. What happens when the D+ ignition wire is connected?
DC-DC charging follows the ignition/alternator ON/OFF signal instead of voltage thresholds. Ideal for smart alternators.

14. What solar input can be connected to the PM635?
Built-in 45 A MPPT:

• Max open-circuit voltage: 42 V DC
• Max charging / supply current: 45 A
• Max array power: 1000 W

15. Can the PM635 operate without a service battery?
Yes. It automatically becomes a 35 A power supply at 12.8 V DC. With AC connected it can supply 35 A to loads while charging at 25 A.

16. How does low-voltage battery protection (BLVP/LVD) work?
Default disconnect:

• Lead-acid / AGM / GEL → 10.5 V
• LFP → 11.6 V
  Reconnect: 11.5 V (lead-acid) / 12.2 V (LFP). 60-second delay. Class D loads remain active. Manual override via LOAD button on display.

17. How are the PM635 load outputs grouped?

• Class A5 (2×) – Relay-controlled, fused, master-switch protected (water pumps)
• Class C2 (10×) – Fused, master-switch protected (lights, fans, etc.)
• Class C3 (2×) – Always-ON, LVD-protected (fridge, alarm)
• Class D (1×) – Constant supply, no LVD (breakaway, radio memory)

18. What is the maximum current available from the Always On output?
40 A rated. Continuous high current is not recommended for long periods. Total L1–L14 usable load is limited to 35 A. Do not exceed 80 A total continuous system load.

19. How does the manual battery switch work?
Side-mounted ON/OFF switch isolates the service battery from the unit and controlled loads. Must be ON for the remote switch to function. Disables DC-DC charging when OFF. Solar charging can still operate.

20. Will solar charging operate when the manual battery switch is OFF?
Yes – this enables solar wake-up and charging during storage.

21. How does the optional remote battery switch work?
Connects to the dedicated WAGO terminals. Manual switch must be ON. Bridge the terminals if no remote switch is used.

22. How does the PM635 measure battery state of charge?

23. What is the PMSHUNT used for?
500 A external shunt for accurate monitoring when high-current devices (inverters, large loads, external chargers) are connected directly to the battery.

24. What do the Reset and Calibration functions for the PMSHUNT do?

• Reset – used after battery replacement (estimates SOC from voltage; fully charge for best accuracy)
• Calibration – forces displayed SOC to 100 % when the battery is known to be fully charged.

25. What does Night Mode do?
Turns off display backlight, reduces fan speed and halves selected charge current.

26. Which water tank probes are compatible?
Up to 4 probes:

• PMWS200 – side mount, tank depth > 200 mm
• PMWS400 – side mount, tank depth 300–400 mm

27. How much ventilation clearance is required?
Minimum 50 mm on each side. Recommended vent opening 144 × 54 mm. Fan-forced cooling – never install in a sealed compartment.

28. What battery-monitor maintenance is recommended?

1. Fully charge from AC mains every 2 weeks when in use.
2. Fully charge from AC at least once every 3 months in storage.
3. Charge until CHG LED shows Float (or monitor indicates Float).

29. How should the PM635 be prepared for storage?
Turn the manual (or remote) battery switch OFF. For long-term storage without power, disconnect all cabling from the battery. Class D and direct-to-battery loads may still draw power.

30. How do I pair a wireless switch panel (PMWSW4)?

1. Enter Engineering Settings (password 1999)
2. Press the “+” icon
3. Press any button on the wireless panel twice slowly
4. Assign functions to each key
5. Confirm

31. Which additional Intelli-GRID accessories can be connected?
Compatible Projecta displays, PMWSW4 wireless switches, SC-series external MPPT controllers, PMDCS30/60/30-20 DC-DC chargers, PMSHUNT, LB-HD / LB-HDCP lithium batteries, PMTPMS tyre-pressure system, PMLVL levelling sensor, INVCHR2/3 inverter-chargers, and temperature sensors.

Troubleshooting Questions and Answers

1. Why does the PM635 have no display or no DC output?
Check manual battery switch is ON, AC plug is secure, fuses, and that the remote-switch terminals are bridged if no remote switch is fitted.

2. Why is the Mains LED flashing quickly?
AC input abnormal – check supply voltage and connections.

3–6. AUX / Solar LED behaviour

• Quick flash → input error
• Slow flash → input present but AC is currently controlling charging
• OFF → input disconnected

7. Why is the CHG LED flashing quickly?
Normal indication that the battery is discharging (supplying loads).

8. Why is the red Fuse indicator illuminated?
Fuse blown – inspect the related device/cabling and replace the fuse.

9. What does a solid red Fault LED mean?
Short circuit.

10. Numbered Fault LED flashes
1 Flash – House battery under-voltage → charge battery
2 Flashes– House battery over-voltage
3 Flashes – Heatsink over-temperature → improve ventilation / reduce load
4 Flashes – Bulk charge time-out → reconnect power source
5 Flashes – DC-DC abnormal → restart unit
8 Flashes – Unit over-temperature
9 Flashes– PCB or load-circuit over-temperature

Safety Warnings

• Explosive gases – provide ventilation, keep flames and sparks away.
• Indoor use only – do not expose to rain.
• Disconnect 240 V before connecting or disconnecting the battery.
• Use an earthed socket.
• Charge only Lead-acid or LiFePO4 batteries of the correct voltage and size.
• Contains a non-serviceable lithium coin cell – keep out of reach of children.
• No user-serviceable parts – opening the unit voids the warranty.
• For long-term storage without power: turn off the battery master switch and disconnect all battery cabling.

When to Contact Projecta Technical Support

Contact Projecta Technical Support if:

• Fault LEDs persist after following the troubleshooting steps
• You suspect internal failure
• You need the latest firmware or wiring diagrams

Always quote the model (PM635) and any displayed error codes.