High powered partnership
February 1st 2009

EnerSys and Linde are keeping costs down, batteries optimised and utilisation high while improving safety at logistics firms such as Culina and Norbert Dentressangle

When we looked at plans for Haverhill we wanted something different," says Jim Seymour, Warehouse Manager at Culina, Haverhill.

"EnerSys worked with the truck supplier to deliver a solution to remove manual handling from battery changing and a management system that takes all the guess work away during charging. Looking at whole life cost benefits we believe the new system will save money over the five years of the contract." Culina has four chilled and five ambient distribution centres, with 1300 employees and 250 trailer units. The Haverhill development opened on schedule in August 2008 and covers 191,000 sq ft housing 17,500 pallets along conventional wide aisle high bay racking in a controlled 0-5C environment.

Culina expects that around 80 per cent of the picking will be by the case once the warehouse is fully operational and that it will be shipping up to 1.5 million cases a week.

This makes the choice of warehouse trucks vital to the operation. Linde and EnerSys had previously supplied Prime Point. Culina asked them to submit joint proposals for the new site while participating in a competitive tender. The requirement was for 15 reach trucks for high bay and general pallet handling and 70 other warehouse trucks to support low level picking and general tasks.

Despite the advanced operations at its existing facilities this was the first major distribution centre fully commissioned by Culina for its own requirements. The company was able to use its experience at Prime Point in particular to identify enhancements to the way it manages warehouse truck batteries.

One of Culina's requirements was to make battery operations efficient and safe by simplifying the change process and minimising the amount of manual handling required. EnerSys devised a layout with the three different types of batteries in separate zones. Batteries for low level order pickers and powered pallet transporters are charged at opposite ends of a single aisle. Reach truck batteries are charged alongside a second aisle that runs parallel to the first.

When one of the small trucks requires a battery change it enters the area and draws alongside the designated charging position. A simple rail-guided trolley is then positioned between the truck and the fully charged battery.

The depleted battery is disconnected from the truck and rolled onto the trolley platform and into the free charging position. The replacement battery is rolled out of its charging position and onto the trolley which is then repositioned before the unit is rolled onto the truck. The whole process takes just a few seconds and is completed without any lifting because the platforms on the truck, trolley and charging position are all at the same level. A simple one-way system eliminates congestion during busy periods and promotes safety.

A different operation is utilised for changing the larger, heavier reach truck batteries. Deciding powered puller changeover would take too long, the company specified a modified mobile powered pallet transporter to bring the batteries to the reach trucks parked adjacent to the chargers. The trucks do not need to enter the charging area or align themselves with specialist handling equipment which means the transfers are faster and more efficient for improved overall productivity.

Another priority was to optimise overall battery performance. This has been achieved by a computerised management system that works in conjunction with the intelligent diagnostic capabilities of the batteries to oversee every aspect of their utilisation.

Batteries are allocated in strict rotation which means that the best available unit, the one with the most charge, is always used.

Battery utilisation is spread more evenly so that none gets heavier usage than the others. The service life of the batteries is prolonged and the risk of unexpected maintenance issues is reduced.

EnerSys supplied its high-performance Perfect Plus batteries which deliver extended work cycles between charges. Charging is achieved by Hawker LifeTech high frequency chargers, with which energy efficiency is as much as 20 per cent higher than traditional 50 Hz chargers.

The charger automatically detects the battery's level of discharge and will supply only the amount of power needed and no more to restore full charge. Electrolyte levels are correctly maintained by the Aquafill system using deionised water manufactured by Culina at Prime Point.

A large display mounted above the charging area indicates where the correct battery, the one with the most charge, can be found. The combination of lift truck, batteries and efficient management ensures that changes are required just once every shift on average.

"The management system should help to ensure the batteries run for the full term," says Jim Seymour. "It reduces opportunity charging and the risk of random selection.

It's so simple it does the work for the guys."

Collaboration at Dentressangle EnerSys and Linde also recently collaborated to optimise power source utilisation and performance for 3PL, Norbert Dentressangle. With its 'Power for Life' service Enersys is able to monitor and manage batteries to ensure the electric lift trucks supplied by Linde continue to support Norbert Dentressangle's ongoing operations in the UK with the same levels of performance, efficiency and value for money over the entire length of a five year contract at each warehouse.

Power for Life is designed to match handling operations to battery resources so that they work as close as possible to their design parameters. Although experience and planning enable Enersys and Linde to predict the likely utilisation patterns very well, it is important to monitor operations during the first year in particular to optimise performance and reduce the risk of problems later in the contract.

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