Structured battery care for peak performance

Recharge your batteries with a spa treatment!

Effective management of truck batteries can save a lot of money – so give your batteries a bit of pampering!

Gian Schiava sees the results at Cat® Lift Trucks’ factory.

The project

Our latest visit to Cat Lift Trucks factory at Almere, the Netherlands, has brought us to the company’s carefully designed battery management system.

What we are going to be shown is how effective management of battery resources can extend their life and ensure that they deliver optimum performance, all the time. A bit of TLC (tender loving care) works wonders!

The end of the truck production line is the start of the battery management system. The origins of the project date back a number of years ago, when the need to tackle random use of batteries was recognised. When an electric counterbalance lift truck comes to the end of the assembly line, it will need a battery for two reasons. The fi rst is obvious; it needs power to drive to the next stage of the production process, where the mast will be assembled onto the chassis before inspection, programming and option fi tting. The second reason is that the truck needs the battery to become a ‘complete product’ and undergo final testing, before proceeding to the shipping area.

The batteries used in these final stages are owned by the factory and will not be shipped to the customer – so they are pretty much in continuous operation. In normal use, these batteries would probably last the standard 6 years or so. To make the most of this resource, Cat Lift Trucks’ engineers developed what they call the ‘8-8-8’ concept. A battery works for a full 8-hour shift, then it undergoes the 8 hour recharging cycle.

Finally, the battery is given 8 hours of complete relaxation, and this is a key element in the whole project.

Cat Lift Trucks formed a pool of about 200 lead-acid batteries, made up mostly of 48 Volt batteries, along with some 24 and 80 Volt units.

They wait at the end of the assembly line to be inserted in the next electric truck and are arranged according to the production schedule. The move-test-proceed to shipping cycle begins and when the truck arrives at the shipping area, the local manager determines whether the battery can return to the end of the line and undertake a whole new cycle, or whether it should go to the charging station.

“...Cat Lift Trucks’ engineers developed what they call the ‘8-8-8’ concept. A battery works for a full 8-hour shift, then it undergoes the 8 hour recharging cycle. Finally, the battery is given 8 hours of complete relaxation, and this is a key element in the whole project.”

Deep clean, recharge, relax

A cycle of treatment that looks like the equivalent of a VIP spa treatment for batteries begins when it is decided that charging is needed. The battery is first measured and is then completely cleaned, to remove exterior dirt, any corrosion, and acid residues. It also receives proper maintenance, such as refilling with clean water, cell replacement and repair or replacement of a broken main connector or cable. When this is completed, batteries are brought into the so-called nursery room to be charged. This area adheres to the highest safety standards, processes and behaviours being reinforced with warning and instruction signs everywhere. A special extraction installation operating with small openings in the walls behind the batteries keeps the air around the units clean. After being fully charged, the battery moves to a rest room, where it can enjoy the 8 hours of rest necessary for full revitalisation.

More than a nice idea

At first sight, it might be thought to be a waste of time to let the batteries wait so long before they are returned to work. In many companies, recharged batteries are put out to work again immediately. The explanation is that the process of charging and unloading is a chemical process and one that benefits from rest from time to time. Even in the apparent quiet time of loading, the chemical process is working as electrical energy is converted back to chemical energy again, which creates heat and other reactions. Letting the batteries rest for a while after charging positively affects battery life.

Batteries should always be fully discharged and recharged again. Ideally, a battery should discharge down to 20% before being recharged. Battery life is around 6 years, or 1500 loading cycles. Hook batteries onto a charging station too soon and you will end up with a ‘lazy’ battery, one that will release its energy faster and faster, resulting in a shortened life. Certainly, there are new technologies that fight this process of ageing and there are also systems that use air bubbles to enable earlier charging (e.g., at 60%) without the negative effects. But that does not take away that rest is good for a battery.

“Batteries should always be fully discharged and recharged again. Ideally, a battery should discharge down to 20%before being recharged.”

Amazing results

All of the above sounds logical but the question is always: does it really deliver positive results? Yes, it does, is the answer. One remarkable fact to note from this factory in Almere is that it is using batteries dating from 1994 – 17 years ago, almost three times normal battery lifetime – and they are still going strong! The initial investment in some extra batteries has resulted in significant savings, by hugely reducing the need for replacement units. The battery management process requires great discipline as it is so tempting and so very easy to take a battery that is fully charged but resting, but the benefits are clear.

“One remarkable fact to note from this factory in Almere is that it is using batteries dating from 1994 – 17 years ago, almost three times normal battery lifetime – and they are still going strong!”

Lesson learned

While this example may be a special, or particular case, it still demonstrates the value of wider, more effective battery management. It is a process that can be implemented in any company that has a fleet of electric forklifts. It requires an initial investment in additional batteries, as well as a battery recharging area that adheres to the highest standards. Fleet operators may also want to invest in initial training of staff, in order to ensure that they understand why certain activities – or lack of activity, in case of battery rest – need to be undertaken. Any professional supplier of materials handling products can help set up this system. It may sound a bit hard to swallow, but setting up this VIP treatment for your batteries will save you money in the end. It is well worth asking about.