Electric Forklift Case Study: Freezer Warehouse at -22°C

A cold-chain operator was running six LPG trucks inside a sealed freezer block at -22 °C. The fumes had to be managed, the lead-acid fleet needed two batteries per truck per shift, and damp air was finding every terminal. We supplied six electric forklift units with lithium packs and sealed drive units. After nine days on site, each truck runs one battery for a full shift, and no battery leaves the freezer.

Project Snapshot

The Problem: A Sealed Box, Frozen Batteries and Fumes

Frozen food warehouses are sealed by design, because every door opening costs energy. That design decision creates three problems at once for material handling.

The first is air quality. LPG and diesel trucks release exhaust into a room with almost no air exchange. Operators work in there for a full shift, and the exhaust also condenses on frozen goods.

The second is battery behaviour. At -22 °C a lead-acid pack gives up a large share of its rated capacity, and it cannot be charged cold. That is why the site kept two batteries per truck and ran a change-over room outside the freezer, which costs labour, space and a forklift of its own.

The third is condensation. Trucks cross between the freezer and an ambient dock many times a shift, so moisture forms on terminals and connectors. Corrosion and intermittent faults follow.

Why We Chose Electric Forklifts Over LPG, Diesel and Lead-Acid

The operator compared four routes.

Keep the LPG fleet. Excluded. It was the cheapest option on paper, but the exhaust problem inside a sealed room does not go away, and fuel handling adds a second set of safety rules.

Diesel trucks. Excluded. Diesel is not an option indoors at all. It also produces more heat, which the refrigeration plant then has to remove.

Electric with lead-acid batteries. Excluded. The site had already proved that this works only with a battery room, a change-over routine and a spare pack for every truck.

Electric with lithium packs. Selected. The trucks emit nothing on site, the pack accepts opportunity charging, and a sealed pack does not need watering or a change-over room.

The Electric Forklifts We Supplied

The order was built around a 3-ton electric counterbalance forklift, which is the size that matches the site's 1,200 kg pallets on 9 m racking. Each truck uses full AC drive and AC lift motors, so there are no brushes to replace and no commutator dust on frozen packaging.

Masts were specified for the racking height with the load centres the site actually handles, and the forks were set for the pallet entry the operator uses. Sealed drive and hydraulic units, plus a sealed lithium pack, keep moisture away from the parts that condense first. The three powered pallet trucks cover the loading dock, where a counterbalance machine is simply slower.

For cold rooms the pack specification matters more than the truck. We sized the pack on the duty cycle the site gave us: lift height, travel distance, pallet weight and stops per hour, rather than on a nameplate figure.

Installation and Charging: How the Switch Ran

The changeover ran in two stages so the warehouse never stopped moving frozen stock.

In week one we commissioned three counterbalance trucks and trained the operators on the freezer side, then moved a full shift onto electric. In week two we repeated the process for the remaining trucks and the pallet trucks. Charging points went in at the dock edge and in a heated room next to the freezer door, which is the practice we recommend: keep the pack out of the coldest zone when it charges, then send it back in.

Operators now plug in during breaks and shift handover instead of swapping batteries. That single change removed the change-over room, the spare packs and the routine of hauling a discharged battery through a door that should stay shut. Our battery charging guide covers how to set those plug-in windows for a multi-shift site.

Testing and Quality Control

Every truck went through a pre-delivery check before it left us. That covered static lift with the rated load, mast drift, brake and steering response, travel and lift speed, and a full charge and discharge cycle with the readings recorded.

On site, we repeated the lift and travel checks with the customer's own pallets, at freezer temperature, with the refrigeration plant running. Each truck was then signed off against a written handover sheet, and the crew was checked off on charging, isolation and daily checks. The first 30 days of operation were logged for charge time and pack temperature so the site could see whether its duty cycle matched the specification. It did, with margin.

Results: What the Numbers Show

Six counterbalance trucks and three pallet trucks are now in service across three shifts. Battery swaps are down to zero. The change-over room has been cleared and reused for staging,.

Throughput held at about 22 pallets an hour on the freezer side. Energy cost per pallet fell once charging moved to off-peak windows, and the refrigeration plant no longer has to remove the heat and exhaust that combustion trucks added. Operators report that the trucks hold their lift speed at the end of a shift, which was the main complaint about the old fleet.

What This Case Means for Your Project

Cold rooms punish equipment that was not specified for them. Three decisions carry most of the result: match the truck to the real pallet and rack height, size the pack on the duty cycle rather than a catalogue number, and keep charging out of the coldest zone.

We build electric counterbalance trucks, pallet trucks and specialised handling units for warehouses, food plants and ports, and we configure masts, forks, packs and attachments to the job. Send us your racking heights, pallet weights, shifts and freezer temperature, and we will size the fleet and get in touch with our team with a quotation and a delivery plan.