The battery power behind street sweeping
20 May 2020
EnerSys has provided a battery to power a pioneering electric street sweeper.
Founded in Italy’s Motor Valley, Tenax International has become, thanks to its modern production plant and international distribution network, one of the world’s leading companies focused on manufacturing, distributing and supporting ecological street sweepers for cleaning and road hygiene. City councils including Paris, Brussels, Krakow and Vigo have relied on these solutions, while users as diverse as major campsites, wineries and large factories have chosen Tenax’s electrical machine to care for their own spaces.
The machine, known as the Electra 01, is the culmination of thirty years’ experience for Tenax. While its electrical concept offered significant ecological and energy-saving advantages, it had to compete in an almost totally diesel-dominated market. To succeed, the electric street sweeper had to provide the same level of autonomy as a diesel solution. Accordingly, Tenax turned to EnerSys as a reliable partner that could consistently supply the battery solutions that they needed.
Opening the doors to electric
Right from the project’s start, both companies understood the challenges they faced. In the street sweeper market, the previous attempts to commercialise an electrical solution failed because the machines were unable to guarantee sufficient operating times. With this in mind, Tenax realised that an unreliable battery could compromise the quality of the entire project. Therefore, the first request to EnerSys was to provide energy to the sweeper machine for an entire shift of eight hours. EnerSys responded by performing a careful analysis, verification and elaboration of the new project. Based on this, EnerSys identified a solution based on a 48V 620Ah battery, which guaranteed coverage of an eight-hour shift. This guarantee was backed by an extended warranty period.
This solution not only completely achieved the target autonomy, but also improved operator safety. The full shift coverage eliminated the need for the operator to change batteries with related risks of acid spillage or recombination gases.
However, to assure market success, the vehicle needed to offer clear economic advantages as well as reliable autonomy. City authorities as main customers expected maximum efficiency and a very rapid return on investment. EnerSys batteries contributed to meet these expectations, as Tenax electric sweepers reduced operating costs up to 90 percent compared to its costs associated with diesel vehicles.
Savings in both energy use and maintenance costs contribute to this reduction.
Monitoring energy to measure performance
However, other factors besides the batteries themselves serve to maximise energy efficiency; EnerSys® also provided their Life IQ high frequency chargers, together with Wi-iQ® battery monitoring device, for checking each battery’s status. The data loggers communicate with the battery chargers and report data in a software package. This information is utilised in optimising charge profiles; this extends battery life, reduces charging times, optimises quality and increases efficiency.
Wi-iQ battery monitoring device also helps Tenax in pre-sales situations, as it allows them to verify the specific cost and performance figures they propose to their prospects. Sales propositions have the credibility of being based on real measured data rather than on estimates or claims.
Another key advantage that EnerSys provided was the possibility to define tailored solutions based on the customers’ requirements. As a standard solution, Tenax offers the Water Less lead-acid battery, with extended topping-up intervals, of up to 13 weeks depending on charger technology, to reduce labour costs. Alternatively, Ironclad batteries are available for long term rental and particularly demanding, heavy-duty applications. They provide higher operating voltages, up to 15 percent more power than other batteries, and rugged reliability for improved productivity and longer life. The battery's design life of 1,800 cycles equates to an extra year of life in many applications.
Other applications have special charging needs, and must run extended shifts. Tenax can fulfil these by using NexSys Thin Plate Pure Lead (TPPL) virtually maintenance-free batteries from EnerSys; NexSys batteries offer increased energy density and fast charging, and can operate in a partial state of charge. They can also take advantage of opportunity charging, for example during driver rest breaks.
International presence and support
Tenax' collaboration with EnerSys extends far beyond the battery technologies. Customers need a partner that can guarantee support across the world, with a portfolio of solutions that can be adapted not only for their differing application needs, but also with the demands of their various geographical contexts. EnerSys provides this, working with Tenax in developing joint consultative solutions for both companies’ international customers.
For example, some customers operate in countries where energy costs are high; they would be more willing to invest in an advanced battery solution like NexSys® batteries. While initial cost would be higher, the greater efficiency and reduced energy costs during the battery’s life cycle would reduce the total cost of ownership. Conversely, a user in a country with lower energy costs would seek a battery with a smaller purchase price.
“Our supplier relationship with EnerSys has been very important for us” commented Vincenzo Guareschi, CEO at Tenax, “EnerSys® support and consultancy has allowed us to offer our customers tailored, energy-efficient operational solutions where savings accrue from both increased battery life, and reduced energy requirements during charging. Additionally, the Wi-iQ® battery monitoring devices provided by EnerSys® allowed us to create a sales strategy based on technical awareness and verifiable data.”
Damiano Sandrini, sales manager Motive Power at EnerSys responded: “Our business relationship has developed into a continuous collaboration that gives us enormous satisfaction. Yet we can still improve and increase levels of energy sustainability by monitoring battery performance and by optimisation to create savings.