They may be big, heavy and full of corrosive liquid, but lead acid batteries still rule the roost. However, new technologies, such as fibre nickel cadmium and lithium ion, are now becoming available. And new battery technologies could mean new designs of pallet truck.
As the power source that doesn’t churn out fumes its not surprising that batteries are viewed as a cleaner option. But recent environmental developments have focused on driving further efficiencies through such technology.
Fibre nickel cadmium, lithium ion and hydrogen fuel cells all have relative pros and cons. But lithium ion seems to have been picked up by manufacturers, particularly for machines such as pallet trucks that don’t rely on the battery to act as a counterweight when lifting heavy loads.
EnerSys has extended its XFC range with lithium-ion technology designed for low-duty pallet truck applications. The batteries can be recharged at any time irrespective of the state of charge without degrading their long-term performance or reliability. They have an on-board charger and are ideal for applications with duty cycles lasting up to 45 minutes where periods of inactivity can be used for rapid opportunity charging.
Sainsbury’s has trialled Toyota’s lithium ion battery technology at one of its largest distribution centres. Toyota commercial director Sam Coles said: “Understanding the practical application of a distribution centre of this size is extremely important to the project. What we have found has aided the development of an efficient battery management system by Toyota which will work with lithium ion batteries to ensure higher levels of productivity.”
And Tesco has run a trial of Jungheinrich’s lithium-ion powered pallet truck, the EJE112i which takes just 30 minutes to deliver a 50 per cent charge and a full charge within 80 minutes, at its a main distribution centres.
Richard Ash, Tesco’s corporate purchasing manager, said: “With its low energy consumption, we believe that the new Jungheinrich EJE112i truck could play a significant role in helping to reduce carbon dioxide emissions across our materials handing fleet.”
With all these strides forward in terms of technology, there is still a long way to go before it is an easy choice for operators. These pilots with major supermarkets are encouraging, but the business case for lithium ion only seems certain for such large scale operations. The technologies cost. Fibre nickel cadmium batteries are around three times more expensive than lead acid, while lithium ion batteries can be nine times more costly.
However, the efficiencies are difficult to dispute. Gus Whyte of Hoppecke points out that if an FNC battery was discharged to 50 per cent and recharged, it would offer around 8,000 cycles compared to just 1,500 with a lead acid battery. And a lithium ion battery could achieve up to 10,000 cycles. Similarly, capacity reduction on a lead acid battery is around 32 per cent, whereas FNC offers between zero and two per cent degradation and lithium ion batteries don’t degrade at all.
“Looking to the future – and this is what excites many in the industry – because they are light and small, lithium ion batteries offer manufacturers of power pallet trucks and multi-pickers the option of designing equipment that is radically different to what is currently in use,” says Whyte.
Craig Johnson of Jungheinrich foresees electricity influencing multiple truck functions. “When it comes to electric powered trucks, forklift manufacturers will continue to develop their electronic controls to ensure faster lift and drive speeds while, at the same time, providing greater efficiency, less battery charging up and longer, more productive shifts.”
One of the key attractions of lithium ion has to be its low maintenance requirements, and Johnson says there a trend for low maintenance batteries in general. He cites the popularity of Jungheinrich’s electrolyte circulation charging system. This enables air to be pumped into the battery to thoroughly mix the battery acid, allowing faster charging and less servicing work because water consumption is lowered.
Hawker has developed the low maintenance Hawker LifePlus, a specially designed charging regime for its high frequency chargers which provides a safe and gentle full charge of the Hawker evolution battery with a low charging factor. Charging time can be reduced to eight hours with 60 per cent depth of discharge. With a complete charge each working day, and a weekly equalising charge, they promise to eliminate water top-ups, and reap energy savings of up to 30 per cent.
Aside from the technologies being developed for fleets of the future, the future of existing traditional batteries cannot be overlooked.
Disposal of old batteries is being governed by increasingly stringent rules. New regulations from the DEFRA state that exhausted industrial batteries must now be recycled and not sold to unregistered scrap dealers. Scrap dealers must have a valid licence or the transaction will be considered illegal.
David Millet of Hoppecke, which has a licence for reselling exhausted batteries, and a factory that recycles them said: “These latest changes mean that in the future it will no longer be enough for companies with a fleet of fork lift trucks to hand their spent batteries to a ‘guy’ who has a garage down the road. Now they need to take real responsibility for what happens to their batteries.”
And some battery components could enjoy an unanticipated second life, according to the FLTA, which warns that the price of heavy metals is making materials handling equipment a target for thieves.
Over the past decade the price of new lead has nearly tripled, from around £300 per tonne to more than £900, which has resulted in a rise in the number of battery thefts.
David Ellison of the FLTA said: “Many of the victims so far have been easy prey for criminals because they simply didn’t realise they were targets. Quite simply, if you use an electric truck, you are.
“Thieves don’t care about the retail or rental cost of the battery – the scrap value alone is what they’re after – so any fork lift truck battery is potentially at risk. Our strong advice is to carefully check the identification and authority of any ‘engineer’ visiting your site – and to ensure batteries are kept very secure when not attended.”
Derek Anderson, managing director for PowerCell Industrial Battery Engineers said: “Any piece of battery-operated equipment could be carrying an asset that has risen significantly in value. But when it comes to protecting that investment, many businesses simply carry on as they always have.
“At PowerCell, we recommend that anyone using an industrial battery review their procedures as a safeguard.”
So with the mounting value of battery components, costly disposal requirements and emerging technology still at a premium, the subject of batteries is something of a minefield, and an expensive one at that. Whether you prioritise output, uptime, running costs or whole life costs, there’s certainly more to it than just those familiar weights that need recharging.
Case study- Hawker for Expert Logistics
White goods home delivery company Expert Logistics has selected Hawker batteries, chargers and management systems from EnerSys to power the lift trucks at its new national distribution centre in Crewe.
Last February Expert consolidated multiple sites into a 360,000 sq ft facility in Crewe. It took a fleet of 22 counterbalance trucks from Toyota with 1.0, 2.0 and 2.5 tonne capacities. A key consideration in choosing batteries was that they must provide enough power to support shift-long performance across such a large site.
The Hawker Perfect Plus range incorporates the Hawker Electrolyte Circulation System which introduces an airflow into the battery to dissipate heat and moves the electrolyte continuously during charging so that it maintains a uniform specific gravity.
As a result, the plates inside the battery are charged more evenly and efficiently with no need for over-charging which would lead to increased gassing. This improved efficiency and presence of the airflow helps to reduce battery temperatures by as much as 10 degrees C.
Charging times can be up to 30 per cent shorter and energy consumption is reduced by up to 20 per cent compared with conventional batteries. Minimised gassing and less sludging help to reduce water consumption by up to 70 per cent which means topping up is required less often.
Chris Adamson, project manager at Expert Logistics who was responsible for commissioning the new facility, said: “These batteries seem to hold their charge for longer which is important because we need our trucks to work hard during every shift”.
The batteries were supplied as a pool which effectively provides two units for each truck. Batteries are charged with Hawker’s LifeIQ high-frequency chargers. Charging and changing is overseen by the Hawker battery management system which communicates in real-time with the chargers to manage the entire process.
Batteries are changed using a Hawker Tugger mounted onto the truck. “The whole operation only takes a few minutes and can be completed by one person with no lifting or stretching,” says Adamson.
The machine pulls up alongside the truck and pulls the depleted battery onto its built-in platform. The battery is placed into a free charging position and the designated fully-charged unit is transferred to the truck. This is simpler and safer than at the previous warehouse where changes required a chain lifting rig.
The company anticipates that the advanced facilities will support its growth plans well into the future. Adamson says: “We know the batteries are being used evenly, that we have enough capacity to run the fleet and have good power management. The tracker system gives greater ownership to the staff who are then more responsible with their trucks.”