United Biscuits has specified EnerSys's Hawker Motive Power brand of batteries and chargers for the lift truck fleet at its Midlands Distribution Centre (DC) in Ashby de la Zouch. The battery installation, which includes a smart 'call-forward' battery management system and a special battery handling arrangement, is crucial in sustaining truck uptime in the DC, which operates round the clock and is annually despatching more than 80 million cases of product.
United Biscuits' Midlands DC says it specified Hawker products and systems because they represent the “very leading edge” in current battery technology in terms of efficiency, energy savings and IT-driven diagnostic and management data methodologies. The Hawker system has also brought great improvements in battery 'housekeeping' and significantly reduces the risk of cell damage – hence extending battery life.
Founded in 1948 United Biscuits is the UK's foremost manufacturer of biscuits and snack products, including such household names as McVities, Jacobs and KP. The company's sales exceed £1.3 billion per annum. The 28,000 sq m Ashby DC, on an 8.8 hectare site, acts as a hub covering the whole of the country. At the heart of the complex are two fully automated 18m high-bay stores, with 40,000 pallet locations served by 22 cranes. Adjacent to these areas is a low-bay store with 11,000 pallet locations and 1,500 ground-level picking faces – orders are picked onto hand pallet trucks.
The low bay store is served by 12 reach trucks, for full pallet putaway and pick face replenishment, and six powered pallet transporters for general handling tasks. Seventeen electric counterbalance trucks are used for loading and offloading. All the electric lift trucks are equipped with Hawker's PerfectPlus high performance batteries, two batteries being allocated for each truck.
Hawker has refurbished the two battery charging areas that are located around the warehouses. One area is for the counterbalance trucks, where the batteries are changed using overhead cranes. The other area is for the reach trucks and pallet transporters, for which Hawker has installed its ProSeries 'Tugger' battery change cart. This is a powered manually operated vehicle that uses an extending electro magnetic ram to transfer batteries between the charging beds and the trucks. This arrangement is quicker and easier, with less manual handling, than United Biscuits' previous chain-drive system. United Biscuits says the system is also safer.
All the battery charging areas have been equipped with Hawker Powertech high frequency (HF) chargers, which offer outstanding energy efficiency – as much as 20 per cent higher than 50 Hz chargers. Powertech chargers automatically detect the battery's level of discharge and will supply only the amount of power needed – and no more – to restore full charge. This means less mains power is required to charge a battery. Thus the energy costs per charge are considerably reduced, leading to significant savings in electricity costs.
Battery Management Systems are installed in both charging rooms. The 'smart' diagnostic software in the Powertech chargers transmits data to large 'Call Forward' display screens that clearly indicate the order in which batteries, for each type of truck, should be retrieved, ensuring that only fully-charged units are taken. This makes certain that all batteries receive the correct amount of charge before being used, and that the batteries are systematically rotated, overcoming the potential problem of operators simply taking the nearest available battery, regardless of its true state of charge.
“Previously each truck was allocated its own pair of batteries,” explains Mike Howells, United Biscuits' Site Operations Manager at Ashby. ” Depending on how hard each truck was working this meant that some batteries were being over-used whilst other were laying idle. Batteries were suffering cell damage as a consequence.
“With the new Hawker Battery Management System we no longer have to allocate individual batteries to specific trucks, because having the smart HF chargers linked to the call forward display will ensure that all batteries always receive the correct charge, and that all are effectively rotated. Cell damage is minimised and battery life significantly extended. The Hawker system is a major benefit.”
Hawker has made the screen-based call forward operation virtually foolproof by devising a system whereby a loud alarm sounds if an operator disconnects a battery that has not been fully charged. Information on unauthorised disconnections, plus a host of other operational data, can be downloaded from the Powertech chargers. All this data is invaluable not just for diagnostic troubleshooting, but also for establishing key performance indicators (KPIs) such as battery availability.
“When seeking a new battery supplier for the Ashby site we were swayed less by traditional, nationwide supply deals than by what was the best available technology on the market, and the safest ” says Mike Howells. “We looked at which supplier was thinking most creatively about factors such as safety, battery fleet management, battery handling systems, energy savings, diagnostic and management data.
“The decision wasn't too hard. When it comes to battery technology, out of all the suppliers Hawker is clearly at the leading edge.”