Linde forklifts with their own Li-Ion solution
The first counterbalanced trucks with lithium-ion battery from Linde Material Handling have been launched on the market. Their great benefit is that they make fleet operators much more independent with regard to power supply – especially in multi-shift operation. This is thanks to the higher energy density and efficiency of the incorporated battery cells, as well as the fact that interim charging is possible any time – factors which result in significantly longer uptime. Moreover, the multi-stage safety concept installed by Linde ensures that the operator and warehouse environment are all safe when using lithium-ion forklift trucks.
For each of the five truck models in the load range from 1.4 to 1.8 tonnes, there are two battery capacity choices, one with smaller and one with larger capacity. If interim charging is easily possible during operations, the smaller battery usually suffices, according to Daniel Butte, Head of Product Management Forklift Trucks at Linde. In the case of the Linde E14 and E16 C (compact), it has a capacity of 13.1 kWh, while the battery for the larger three-wheel models, Linde E16 and E18, and the four-wheel model, E16 P, comes with a greater capacity of 16.3 kWh. However, it is advisable to use the more powerful batteries with a capacity of 39.2 kWh and 45.7 kWh respectively if the operating conditions demand above-average performance from the trucks or if there is a need for vehicle availability over two shifts. Two charging devices of different capacities are also on offer, which form a closed system together with the batteries. “The power of the charger and the battery size determine how fast a battery is charged,” explains Butte. “It takes about 50 minutes to charge a completely flat small-capacity battery with the large charger. Charging a maximum capacity battery with the small charger can take more than six hours.”
System matched to forklift operation
However, horses for courses as the saying goes. All forklifts are not all the same and starting immediately, this also goes for the battery technology used. Customers who buy a Linde E14 to E18 ION, will receive a CE-certified complete system consisting of the truck and the battery, which is exactly matched to the application requirements, and together with the charger supplied by Linde, the advantages of the new battery technology can be fully exploited. 2,500 full charging cycles with a subsequent remaining capacity of the battery of at least 80 percent are guaranteed. Another characteristic is the simple handling: All it takes is for the driver to open the flap at the rear and connect the charger and socket – done! The extensive safety features and measures are a further exemplary attribute, emphasizes Butte. These start at the cell, module and battery levels and prevent damage caused by excess pressure, overheating as well as overcharging or deep discharging. Additional protection is provided by the installed shock sensor that monitors impact on the battery and prevents misuse, and by a patented system that burns up regenerative braking energy instead of feeding it back into the battery when there is a risk of overcharging.
The battery management system takes over the function of a control centre and thus has an important role in the trucks’ high safety level. It monitors all battery-relevant parameters, informs the operator about possible, battery-damaging behaviour and ensures that the vehicle is placed in a controlled state in the event of a technical defect. A battery compartment of 25 mm thick steel protects the battery cells against damage from the outside. Numerous trials have been carried out to verify that the system is efficiently protected against external influences.
Extensive tests confirm robustness and safety
As usual, the trucks were also put through their paces in a roundabout-test – and there was a debut: “For the first time ever, we tested the functionality and stability of the complete system – electric truck including battery,” says Butte. The test result was extremely satisfactory: “With lithium-ion electric trucks it’s no longer necessary to use external power supply to carry out this test. Unlike with trucks fitted with lead-acid batteries, where this is not possible to date, since the constant vibrations would damage the battery,” says Butte. Furthermore, the truck with li-ion battery mastered the crash test, in which a fully loaded 8-tonne forklift driving at top speed crashed into the side of a 3-tonne electric forklift. The fork did not penetrate the rugged Linde lithium-ion battery compartment.
Following the successful trials on Linde’s own test ground, the trucks were sent off to field tests at customers in a wide range of industries. “All the customers enthused over the benefits of the new battery technology and were completely satisfied,” Butte sums up the initial feedback from the market. “Consistent performance during operations, time gained through interim charging, the elimination of a replacement battery, and obsolete battery maintenance were among the most frequently cited advantages.”
