LiFePO₄ battery bank
Modular 16 kWh packs. Standard configurations from three packs (48 kWh) to nine packs (144 kWh), matched to your duty cycle.
Rigid-first electric refrigeration
Battery-electric power for Carrier rigid refrigerated trucks.
The Elmech eTRU is built first for South African rigid refrigerated trucks running Carrier Transicold units with electric standby. It feeds the existing standby input from an onboard battery, solar, and inverter stack; the refrigeration controls, compressor, and fans remain unchanged. Trailer applications are assessed separately.
Native Carrier integration · COP optimisation · Preemptive fault detection · Carrier diesel engine: near-zero run hours
Product at a glance
A hardware product, with the portal included.
The Elmech eTRU replaces the diesel engine driving your refrigeration unit with a battery-electric power source. It is a retrofit: the existing Carrier unit with an electric standby motor stays in place, and the eTRU connects to its electric standby supply input. The cargo stays at temperature; the diesel engine stays off.
- Vehicle class
- Primary fit: 4-ton to heavy rigid refrigerated trucks. Trailer systems assessed per application.
- Standard stack
- Battery · Solar · Inverter
- Build + install
- ~3 weeks (subject to truck availability)
- Warranty
- 5 years, within electrical specifications. Road accidents and similar external events are excluded.
- Service area
- Nationwide, South Africa
- Pricing
- Once-off purchase or Cooling-as-a-Service funding
- Company
- Elmech (Pty) Ltd, George. Startup, founded on 20+ years of solar engineering experience.
Retrofit, not replacement
How the eTRU connects to your truck.
Every Carrier refrigeration unit fitted with an electric standby motor accepts an AC power feed at the depot — that's the standby input. The eTRU plugs into that same input, but onboard, fed by a battery bank, rooftop solar, and a depot grid charger. The refrigeration unit's electronics, compressor, fans, and the diesel engine itself are left in place. The diesel engine simply stops being used.
What's in the unit
The hardware, component by component.
Rooftop solar array
2 to 5 kW of PV, sized to fit the rigid body roof area. Trailer roof layouts are assessed separately during fitment review.
Inverter / charger
Industrial-grade inverter/charger stack. Three-phase 230 V output, feeding the refrigeration unit's standby supply input.
Solar MPPT controller
MPPT controller manages the PV array and writes harvested energy to the battery bank.
Depot grid charger
Single AC input at the depot. Full charge in under four hours, regardless of pack count.
Edge controller
Reads telemetry from the battery, inverter, MPPT, and the TRU's serial bus. Streams the data to eTRU Insights for measured savings verification.
Specifications
Performance & specifications.
- Energy capacity
- 48 – 144 kWh, in 16 kWh increments
- Battery chemistry
- LiFePO₄
- Solar capacity
- 2 – 5 kW, sized to the roof area
- Grid charge time
- Under 4 hours, full charge
- Vehicle classes
- Primary fit: 4-ton to heavy rigid refrigerated trucks. Trailer systems assessed per application.
- TRU compatibility
- Any Carrier refrigeration unit with an electric standby motor
- Standard stack
- Battery · Solar · Inverter
- Build location
- George, Western Cape, South Africa
- Lead time
- ~3 weeks from order (subject to truck availability)
- Service area
- Nationwide, South Africa
Safety and commissioning
Safe energy, non-negotiable.
Elmech does not publish certification claims until formal documentation is issued. Every rigid-truck deployment is scoped through a practical engineering review before build and commissioning.
- Battery chemistry
- LiFePO₄ battery packs selected for stable thermal behaviour.
- Depot electrical review
- Charging supply, protection, parking layout, and overnight charging window checked before quote finalisation.
- Vehicle fitment review
- Carrier unit, standby input, rigid body layout, roof area, and payload impact reviewed before build.
- Commissioning
- First-trip telemetry, charging behaviour, cargo temperature, and diesel runtime displacement checked before handover.
Compatibility
If your TRU has an electric standby motor, it's compatible.
Most modern Carrier units sold in South Africa are already fitted with an electric standby motor — the motor used to drive the refrigeration unit from an AC plug at the depot. The eTRU uses that same input. There is no change to the refrigeration unit itself, no change to its diesel motor, and no change to the driver-facing controls.
Rigid use cases
Where the eTRU fits first.
The strongest early fit is a rigid refrigerated truck that returns to a depot, parks long enough to charge, and runs predictable chilled or frozen delivery routes.
Supermarket distribution
Regional depot-to-store routes with strict delivery windows and repeatable cold loads.
Frozen and chilled last mile
Frequent stops where diesel reefer idle time, noise, and fuel cost add up quickly.
Pharma and vaccine delivery
Temperature-critical rigid trucks that need auditable cargo logs and route-level reporting.
Return-to-depot fleets
Vehicles with overnight depot parking, known charging windows, and measurable daily run-hours.
Rigid truck fitment guide
Sized around truck length, setpoint, and route profile.
The fridge.li brochure sells rigid-truck fitment with a simple table: truck length, setpoint, system, cooling capacity, and runtime. Elmech uses the same buying logic as a fitment guide rather than a fixed promise until enough fleet data is collected.
| Rigid truck profile | Typical setpoint | Fitment focus | What Elmech confirms |
|---|---|---|---|
| Short urban rigid | 0°C chilled or -20°C frozen | Door openings, stop density, depot charge window | Battery pack count, rooftop PV area, Carrier standby input |
| Mid-length regional rigid | 0°C chilled or -20°C frozen | Route duration, idle hours, cargo profile | Energy capacity, charger sizing, monthly savings model |
| Heavy rigid / high-duty route | Application-specific | Runtime target, payload impact, fallback strategy | Fitment review, first-trip telemetry, duty-cycle report |
Trailer applications follow the same review, but roof layout, axle loading, trailer switching, and depot charging access are assessed separately.
From order to running cold
On your fleet in about three weeks.
Each step is a discrete handoff. Operators see verifiable progress from quote through to the first trip running cold.
01
Quote
A 20-minute technical call to map your fleet, vehicle classes, and TRU models. We confirm fit and issue a written quote.
02
Workshop
The unit is built in George around the standard battery, solar, and inverter stack, sized to your duty cycle.
03
Fitting
Battery bank, inverter, MPPT, and solar array are fitted to the truck. The eTRU is wired into the existing standby input.
04
First trip
The truck runs cold on battery power. eTRU Insights starts streaming live telemetry from the first kilometre.
Verified savings
Measured, not estimated.
Every eTRU continuously measures the grid kWh consumed at charge and the energy delivered to the refrigeration unit on the road. The diesel litres displaced are calculated from those measurements — not estimated from generic assumptions. Each customer sees their own fleet's verified savings on eTRU Insights, the portal that ships with every unit.
Native reefer integration Live COP optimisation OEM-baselined diesel displacement Hosted in South Africa
Native Carrier integration COP optimisation Preemptive fault detection Carrier diesel engine: near-zero run hours
Lifetime cost comparison
A lifetime of more, for less.
Maxwell+Spark's rigid-truck brochure makes the value case visually: compare capital, energy, and servicing over the operating life. Elmech makes the same decision easier for rigid-truck fleets, using our own measured diesel displacement and quote-specific inputs.
Visual comparison is indicative only. Final payback and ownership cost are calculated from your Carrier unit, rigid-truck duty cycle, diesel price, depot electricity cost, and measured eTRU telemetry.
Two ways to buy
Once-off purchase or Cooling-as-a-Service.
An eTRU can be bought outright as a once-off capital purchase, or financed through our Cooling-as-a-Service programme: a fixed monthly fee per truck with no upfront capital outlay. At the end of the CaaS term, ownership of the hardware transfers to you. Terms and pricing are issued per quote and depend on fleet size and duty cycle.
Five-year warranty
Backed by Elmech, serviced nationwide.
Every eTRU carries a five-year warranty against electrical defects, within specification. Road accidents and similar external events are excluded. Service is delivered nationwide across South Africa by Elmech engineers, supported by the workshop in George where every unit is built.
Frequently asked
Questions we hear from fleet engineers.
Do you supply the hardware or only the portal?
Turnkey hardware. Every eTRU ships as a complete unit built and commissioned by Elmech: a LiFePO₄ battery bank (modular 16 kWh packs, 3 to 9 per unit), industrial-grade inverters and a solar MPPT, a 2 – 5 kW rooftop PV array, a variable-frequency drive that sits between the inverters and the refrigeration unit's electric standby motor, the edge controller, and the depot grid charger.
A depot AC upgrade and safety-compliance work is recommended where the existing depot supply doesn't meet the load. eTRU Insights — the savings-verification portal — ships with every unit.
Which TRU manufacturers are supported?
Any Carrier refrigeration unit fitted with an electric standby motor is compatible with the eTRU. The eTRU feeds the same AC input the standby motor already uses at the depot — onboard, from the battery bank — so no modification is made to the refrigeration unit itself, its controls, or its diesel engine.
Other manufacturers are not supported.
Talk to an Elmech engineer.
A 20-minute technical call to map your fleet, vehicles, and TRU models against what the portal can verify on day one.