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Articles & Info

October 31, 2012
31 Oct 2012

What to look for in an electric forklift

Electric forklift traction batteryWithout doubt the biggest innovations and improvements in the last 20 years in materials handling have been in the electric equipment industry. While LPG and diesel forklifts remain a mainstay in factories and loading facilities Australia and world-wide, electric lift equipment has increasingly become a mainstream choice. But to many people, even industry insiders with extensive experience, electric forklifts remain a mystery. We’ll try to explain here what to look for when purchasing, what sort of equipment to buy to meet your needs and the common pitfalls to avoid.

Electric Forklifts – the basics

Electric forklifts are used just as internal combustion forklifts are – to move goods from one place to another. The method in which they go about this can be very different though. All electric forklifts vary in some way, however the basic electric forklift will have the following features:

Battery

This is the power source for operating the forklift. The battery is charged overnight, usually using a separate charger, and then plugged into the forklift. The battery is used for 3 purposes: Operating the drive motors to move the forklift forward and back, operating the hydraulic motor to power the lifting and tilt operations of the mast, and operating ancillary equipment (lights, dashboard, horn etc). The power will be divided among these and governed by a sealed industrial computer located in the dash or counterweight areas.

Forklift batteries are called traction batteries, and are typically of lead-acid construction. They are characterised by their division into many large cells. Usually the voltage of the forklift can be determined by multiplying the cell count by two. 12 cells = 24 volt battery. 24 cells = 48 volt battery etc. However this is merely a guide and many variations exist.

Drive motor

The drive motor is just a big electric motor. It receives power from the battery and speed control from the computer and drives the wheels forward or backward accordingly. One of the advantages to electric forklifts is that the drive motor is next to the wheels and drives them directly, minimising driveline power losses and lag, and simplifying the driveline system. Less parts = better reliability and reduced servicing cost.

Hydraulic motor

The hydraulic motor usually sits under the floor in a counterbalance forklift. It serves a similar purpose to the hydraulic motor in a internal combustion forklift – to power the hydraulic system, however it is driven by electric current from the battery rather than belt or flywheel driven from the motor in a diesel or petrol powered forklift.

Hydraulic system

This is the part of an electric forklift most like a conventional forklift. powered by hydraulic fluid from the hydraulic motor, the hydraulic system makes the hydraulic rams operate, raising and lowering the mast, tilting the mast and performing other similar load functions.

Counterweight

The counterweight on a counterbalance forklift serves to keep the heavy load on the tynes at the front of the forklift from tipping the unit over. It is typically cast solid steel. Electric forklifts in general have a much smaller counterweight as the battery makes up so much of the mass of the vehicle and eliminates much of the need for a larger counterweight

Wheels

As per a normal forklift, the wheels enable the forklift to drive and steer. Because electric forklifts are designed for interior use, the wheels are often made from special compounds, such as non-marking rubber or urethane

Model variations

This is where it can get interesting (and confusing). Unlike conventional forklifts which have relatively few type variants, electric forklifts and lift equipment can come in a huge variety of types and sizes. Here are a few of the most common ones

Pallet mover

common in cold stores and large warehouses with rapid turnover, this is the electric version of the venerable pallet jack. It can raise up from the ground about 100mm, carries a large load for it’s size (1-2.5 tonne) and allows quick transport of goods around a factory, or into a pallet or truck. Typically it has a 12-24 volt battery and an integrated 240 volt charger

Walkie stacker or straddle stacker

Popular for light use and surprisingly versatile, the walkie stacker has 2 straddle legs that extend out either side of the load. These enable the operator end to be very compact – avoiding the need for a large counterweight (though counterweight versions are available without the straddle legs if required). Walkie stackers are often used in situations where there can be a lot of different operators, minimal training is required to operate one and no operator license is usually necessary. (Please check with your local OH & S authority)

Walkie stacker with reach

An attempt to negate the disadvantage of the straddle legs on a walkie stacker, the ‘walkie-reach’ is becoming more popular over time. This type of forklift incorporates a normal walkie stacker with an additional hydraulic circuit which powers a reach facility. This is a scissor type boom that the carriage and tunes are mounted on. When the reach button is pressed, the carriage extends out from the forklift. The best known use for this feature is avoiding the wheels of a truck when loading (a frustration operators of conventional walkie stackers can relate to)

Reach truck

Available in stand up or sit down models, Reach trucks are a step up from walkie stackers in every dimension. The operator is mounted sideways, enabling easy vision forwards and backwards, and the operation is controlled by a steering wheel and joystick (typically). Larger straddle arms and a heavyweight mast mean that reach trucks can lift up to 2 tonnes at a time. A larger 36 or 48 volt battery is necessary, along with a separate, often 3 phase charger. Reach trucks are able to lift to enormous heights, up to 12 metres in modern specialist models. This, along with their tight turning circle mean that they are a popular design.

Order pickers

A variation on the reach truck theme, order pickers raise the driver up with the carriage – enabling him or her to pick goods from a pallet without moving it to the ground. This can be of enormous advantage in certain industries.

Counterbalance

Most like a traditional forklift, counter balance electric forklifts are well regarded for their similar operation to a conventional engine powered unit, enabling drivers to quickly hop from one to another. They have excellent speed and better ground clearance than most other electric forklifts. 3 wheeled variants are available that have very good turning circles

Other less common models

Work assist vehicles, tow tractors, narrow-aisle turret reach trucks and more are available to you if you need them. Keep in mind the rarer the unit, the higher the initial and ongoing cost, and often you can have difficulty reselling the forklift privately.

Pros and cons to owning and running an electric forklift

Pros Cons
Lower daily running costs – no lpg or diesel consumption Restricted to level, even concrete or asphalt operation – no gutters or driveways
Simplified servicing – reduced costs and less frequent servicing required Larger and more complex computerised parts, greater chance of electronic failure
Quieter, smoother operation No towing ability
Zero emissions – essential for operation around food products No easy ability to quickly recharge or hot swap batteries
Smaller motors and no physical drivetrain or transmission means vastly more flexibility in body style and configuration generally limited in capacity to 2.5 tonnes or below, with most electric forklifts below one tonne

Summary

We hope this guide has been helpful to you in selecting the right type of forklift. Electric forklifts come in many shapes and sizes, but with a little knowledge selecting the right type of forklift for your needs can be easy. Why not contact us today for great advice and prices on all types of forklifts – electric or otherwise!