Dometic MT MPP
Official technical documentation and workshop diagnostics for MT MPP.
Technical Specifications
ElectricalNominal battery voltage: 12V DC (Lead), 12.8 - 13.2V (LiFePO4). Standby current consumption: 4 mA. Unit fuse (Type FKS): 15A (MPP170), 20A (MPP260), 30A (MPP440). House battery output currents: 0-12.5A (MPP170), 0-18.5A (MPP260), 0-32.0A (MPP440). Starting battery auxiliary current: 0-1.0A. AES/RE terminal switching current: max 0.2 A.
Gas Or PressureSolar panel voltage (Voc): < 50 V. Solar panel current: 0-10.5A (MPP170), 0-16A (MPP260), 0-26.5A (MPP440).
Capacities DimensionsRecommended solar panel output: 40-170 Wp (MPP170), 50-260 Wp (MPP260), 50-440 Wp (MPP440). Recommended battery capacity (Lead): >40 Ah (MPP170), >60 Ah (MPP260), >100 Ah (MPP440). Recommended battery capacity (LiFePO4): >30 Ah (MPP170), >45 Ah (MPP260), >90 Ah (MPP440). Dimensions including mounting flanges: 131 x 77 x 40 mm. Weight: 225 g (MPP170), 235 g (MPP260), 285 g (MPP440). Protection type: IP20. Ambient operating temperature: -20 °C to +45 °C.
Master Troubleshooting & Diagnostics Matrix
| Error Code / Indicator | Symptom / Meaning | Step-by-Step DIY Fix | Suggested Actions |
|---|---|---|---|
N/A | The MPP solar charger does not work. Possible Cause: Insulation faults, breaks or loose connections at the live cables, or a short circuit triggered the device fuse. | Check live cables for insulation faults, breaks or loose connections. Replace the device fuse via an authorized service agent if triggered by excess current. | DIY Check / Tech Fallback |
N/A | The MPP solar charger does not work. The 'MPP' LED is flashing. Possible Cause: No solar panel power generated (night mode) or generated solar power is too low due to objects or dirt blocking light. | Check for obstructions, ensure solar panels are not blocked by shadows, and remove any dirt. | DIY Safe |
N/A | The MPP solar charger does not work. The 'Laden' LED is flashing quickly. Possible Cause: Over voltage protection of the house battery (> 15.0 V). | Reduce connected voltages. The charger restarts automatically when the voltage drops below 15.0 V. | DIY Safe |
N/A | Unusually long charging time. The 'Laden' LED is flashing quickly. Possible Cause: High temperature protection (> 50 °C battery temp) or low temperature protection for LiFePO4 batteries (< 0 °C). | For high temperature, the charger returns to full voltage when temp drops below 48 °C. For LiFePO4, move the battery to a location > 0 °C. | DIY Safe |
N/A | Unusually long charging time. The 'Laden' LED is flashing slowly. Possible Cause: Low temperature protection for LiFePO4 batteries (< -20 °C). | The charger returns to full charging voltage automatically when the temperature exceeds -18 °C. | DIY Safe |
N/A | Low battery voltage. The '>80%' LED and 'Batterie/n voll' LED light up. Possible Cause: No connection from the MPP solar charger to the battery, incorrect cable cross-sections, or stripped ends/fuses issue. | Check connections, cable cross-sections, cable lengths, fuses, stripped cable ends, and voltages directly at the terminals. | DIY Safe |
N/A | The 'Schwach' LED lights up (only MT MPP 170). Possible Cause: Low voltage (< 10.6 V) at the house battery. | Charge the house battery to avoid under voltage. | DIY Safe |
N/A | All LEDs are flashing simultaneously. Possible Cause: The charging program is not set correctly. | Check the setting of the charging program according to the battery type used via DIP switches. | DIY Safe |
N/A | AES/RE terminal does not work. Possible Cause: No excess solar power generated or load of connected consumers too high (output current exceeded 200 mA). | Reduce connected DC loads so current draw remains under 200 mA. | DIY Safe |