Retrofit

TwinDrive Cooling™ + QuadPhase Power™

Turn an absorption fridge into a smart, quiet, dual-zone 12V system — precise temps, real efficiency, and days of autonomy from solar, alternator, shore, and a compact LiFePO₄ battery.

What is the retrofit?

A clean, rear-mounted conversion: we keep your cabinet, insulation and fascia; we replace the heat source with a high-efficiency 12V compressor system and add smart control.

  • TwinDrive Cooling™ — two circuits (freezer + fridge) for true dual-zone control and flexible modes.
  • QuadPhase Power™ — power from shore (AC), solar, alternator and LiFePO₄ battery, managed intelligently.
  • No gas, lower running cost, faster recovery, stable temps on the move.
Freezer zone Fridge zone Evaporator A Evaporator B Compressor + Controller
Two dedicated evaporators → faster pull-down and more stable temps.
AC Shore Solar Alternator LiFePO₄ QuadPhase Controller 12V Compressor

How it works

  • TwinDrive Cooling™: independent control of freezer/fridge; run both, turn one off, or swap roles when needed.
  • QuadPhase Power™: prioritises free energy (solar/alternator), falls back to battery, and uses shore when available.
  • Rear-mount retrofit: neat install behind the cabinet; no need to rebuild fascia/insulation.
  • Quiet & efficient: compressor average draw ~35–45 W (typical use, temperate weather).

Energy System (solar • alternator • shore)

  • Base battery: ~500 Wh LiFePO₄ (≈40 Ah @ 12 V) → daily cycling, compact footprint.
  • Solar: 200 W covers a typical day; scale to 300 W for heat waves/heavy usage.
  • Alternator boost: 30–50 A for 1 h → ≈0.36–0.60 kWh back (often enough for the next day).
  • Shore: seamless switchover for campsites and winter storage.

Numbers are indicative; autonomy depends on ambient, loading habits, and compartment use.

MPPT Solar DC-DC Alt Shore Distribution 12 V Loads Fridge LiFePO₄ 500 Wh (≈40 Ah @ 12 V)

Dometic

RM7/RM8/RMD/RMS families — check eyebrow/control boards and sensors before deciding. Fault codes and mapping here.

Fault codes →

Thetford N-Series

Many units are compatible; verify wiring and NTC placement. If panels are obsolete, retrofit becomes a clean step up.

Guide →

Electrolux (EU)

Common absorption models in EU caravans/motorhomes — typical faults and electronic notes covered here.

Guide →

If a cheap repair solves it, we’ll say so. If parts are obsolete or unstable, the retrofit saves time and gas.

Install overview

  1. Remove absorption heat stack; keep cabinet, fascia and insulation.
  2. Fit rear-mounted compressor module + TwinDrive evaporators.
  3. Route sensors/looms; verify door seals and airflow paths.
  4. Connect QuadPhase power: MPPT, DC-DC (alternator), shore and LiFePO₄.
  5. Commissioning: pull-down test, zone tuning, fault-free run.

What you keep

Cabinet, doors, fascia, interior shelving. Minimal visual change — maximum function.

What you gain

Stable temps, no gas, lower running cost, quieter nights, autonomy off-grid.

TwinDrive Cooling™

  • Independent fridge/freezer circuits
  • Flexible modes (dual-fridge, freezer-only, swap)
  • Faster recovery, fewer cycles

QuadPhase Power™

  • AC shore • Solar • Alternator • LiFePO₄
  • Smart priority of free energy
  • Seamless switchover, protected

Energy & Autonomy

  • Avg draw ~35–45 W (typical use)
  • Base battery ≈500 Wh; solar 200–300 W
  • Alt boost 30–50 A ≈ 0.36–0.60 kWh/h

FAQ

Is a 12 V compressor retrofit really quieter?
Yes — no burner or flue noise, and the compressor runs in short, efficient cycles.
Can I keep using gas?
The retrofit is an all-electric path (12 V + AC). If gas is mandatory for you, we can first stabilise the OEM system — see Diagnostics Hub.
What battery do I need?
Start with ~500 Wh LiFePO₄ (≈40 Ah @ 12 V). Add solar (200–300 W) and alternator DC-DC for your travel pattern.
Will doors/shelves change?
No — cabinet, doors and interior stay. The work lives behind the fridge.

Ready to make the switch?

Tell us your model and use-case. We’ll map the shortest route: repair, board swap, or full retrofit.