Charging without load peaks - Behrens-Wöhlk GmbH & Co. KG
Fronius battery charging technology improves operating procedures at timber wholesaler Behrens-Wöhlk.
In order to supply its customers reliably and on time, smooth intralogistics processes are indispensable for timber wholesaler Behrens-Wöhlk – in particular at the central warehouse in Drensteinfurt, North Rhine-Westphalia. Here, electrically-powered forklift trucks ensure efficient and emissions-free goods transport. However, in the past the battery charging technology has been a source of problems, with unwanted load peaks causing frequent malfunctions in operating procedures and resulting in high costs. Fronius Perfect Charging has not only overcome this challenge with its Selectiva battery chargers, but it has also enabled the Behrens Group to achieve considerable cost savings and extend the service life of the traction batteries.

Worktops and doors, steps, wall and ceiling elements, boards and parquet: at the central warehouse of BERO Holzhandelsgesellschaft mbH in Drensteinfurt near Münster, countless wood products are stacked as far as the eye can see. At the nearby site of Seiling GmbH & Co. KG in Ahlen, construction and insulating materials, floors, carpentry supplies as well as a comprehensive range of accessories are stored. The noticeable thing about both sites? The characteristic smell of the material in the air, and the low level of noise. Although numerous forklift trucks move back and forth between the aisles of the high-bay warehouse, it is pleasantly quiet. The typical diesel smell outdoors in many locations? Also non-existent.
Both companies are part of the Behrens Group, which - with a total of 14 sites - is one of the leading wholesalers of timber and construction elements in Germany. The supply region covers extensive areas of federal states North Rhine-Westphalia, Lower Saxony, Bremen, Hamburg, Brandenburg, Saxony-Anhalt, Thuringia and Saxony. With roughly 850 employees, the Behrens Group generates a turnover of around 250 million euros per year. Andreas Jedamzik reports that the industry is booming even during the coronavirus pandemic: “We haven’t recorded a drop in sales since the beginning of the crisis.” Building work is continuing as usual and renovations during periods of lockdown and curfew have even been going ahead more often than before.
The timber wholesaler is now focusing on sustainability
As fleet manager at the Behrens Group, Andreas Jedamzik is responsible for the vehicle and forklift truck fleet. The Group operates 115 forklift trucks, 16 of which are electrically-powered lateral stacking trucks and special devices used for picking at Drensteinfurt. These transport goods (sometimes weighing tons) reliably and efficiently from goods in into the warehouse and then for dispatch. “The subject of sustainability is extremely important to us,” explains Jedamzik. “We use modern, economical drives in our vehicles and it is possible that we may switch to hydrogen technology in the near future.” And the truck-mounted forklift? “Here, 40 percent of our forklift trucks are electrically driven. We are now investing exclusively in electric truck-mounted forklifts, and by 2022, we will be the first timber wholesaler in Germany to have a fleet that is 90 percent electrically driven.” The Behrens Group is therefore also considered a pioneer in the industry in this regard.

Unwanted frequency interference due to outdated charging technology
In the past, the company had used different high frequency (HF) battery chargers from other manufacturers, which sometimes led to major problems. “We had heavy frequency interference in our grid,” recalls Jedamzik. “This was due to load peaks and harmonics, which occurred when we had connected several forklift trucks to the devices for charging at the same time. The high power consumption at the beginning of the charging phase meant that our IT system crashed regularly and we were always having to call on our technicians to perform special tasks.”

The result was significant limitations regarding operating procedures and unnecessary costs - a situation that the fleet manager did not wish to and was no longer able to longer accept.
Jedamzik discovered the extremely cost-effective and stable Fronius charging technology, which offered a good technical solution and decided to test it out. As early as the testing phase with the first Selectiva devices, the interference was reduced significantly. The in-house developed Ri charging process is responsible for this, which the Fronius battery chargers are equipped with. Compared to conventional processes, this enables steady distribution of the energy demand throughout the entire charging period. The devices also have a special calendar function, which can be used to set charging to start at a defined time. “Fronius charging technology allows the customer to charge forklift trucks at different times and avoid dreaded current peaks, even when several vehicles are connected at the same time in the evening,” explains Matthias Leibold, technical support expert at Fronius Perfect Charging. This solution impressed across the board, and the entire Behrens Group has switched to Fronius charging technology.
Reduced electricity consumption and longer service life
The Selectiva battery chargers offer a whole host of additional benefits. The Ri charging process is not only able to reduce load peaks, but the innovative charging technology also allows for extremely energy-efficient operation. Unlike other processes, this process works according to the effective inner resistance (Ri) of the connected battery and adapts the characteristic accordingly. “Each charging process is therefore unique and the battery characteristics are detected automatically. This means that each battery receives the exact amount of energy it requires,” says Leibold. “This reduces energy consumption and harmful heating of the batteries during charging, extending the service life of the battery by up to 30 percent. In addition, capacity is maintained for longer.” The Behrens Group can therefore save on energy costs and has to replace the expensive traction batteries less frequently – a real bonus for the company concerned with sustainability. “What’s more, thanks to the automatic voltage detection, we can connect any battery to any battery charger,” adds Jedamzik. “This makes handling easier and, coupled with the extremely high quality and low failure rate of the Selectiva battery chargers, ensures a particularly high level of availability for our forklift truck fleet.”
The electrolyte circulation system (ECS), which earlier battery chargers were equipped with, is no longer required for the new Fronius technology. “Many manufacturers offer the ECS as additional equipment to reduce the temperature during charging and in turn extend the service life of the batteries, reduce energy consumption and increase availability,” explains Matthias Leibold.

Forklift trucks powered from the company’s own roof
The collaboration between the Behrens Group and Fronius doesn’t stop there either: the specialist in wood materials has already equipped some of its sites with a photovoltaic system. “Our aim is to be able to generate a significant amount of the required energy ourselves, as this is another key aspect of our sustainability strategy,” explains Jedamzik. The inverters used, which convert the direct current produced in the PV modules into usable alternating current are also from Fronius. “Here in Drensteinfurt we are also working on the construction of a photovoltaic system as part of site development,” says Jedamzik, providing an insight into the near future of the company. “This will then be equipped with Fronius inverters.” The highlight is that BERO can then use the self-generated solar power directly for operating the forklift truck fleet and thus also reduce energy costs. “The intelligent solution from a single source, which we can use to save costs and reduce our ecological footprint at the same time, has thoroughly impressed us,” says the extremely satisfied fleet manager.