Q&A

Every Banke system contains all the components that are required for its function - to take current from the grid and deliver hydraulic oil flow under pressure. Additionally, we mount the system in such way that each component or each individual battery cell can be exchanged in service. The major components are the battery cells, the battery management system, the power inverter, the electromotor, the hydraulic pump, the battery charger and the control system.

A full plug-in system can recharge with energy that is generated by clean sources like solar, wind or water. When recharging the batteries with a generator, the energy needs to pass a string of components that all have their inefficiencies. Even when the chassis is delivering energy at its optimal performance point and the generator/charger combination is best in class, the fuel consumption will increase. In fact, recharging batteries during driving costs more fuel then when using the normal (mechanical) power take off from the chassis. Unless sufficient fuel can be saved by switching off the chassis, Banke does not advise recharging of batteries during driving.

The Banke body communication is either based on CAN communication or is hardwired. In both cases the connection is made through a rugged 6-pole Harting connector. Interface specifications are available on request.

This was measured by DELTA (Denmark TC-100154) according to 2000/14/EC and EN ISO 3744:1995. Measurements proved a 7 dB noise reduction when using an E-PTO. The results are backed up by Lindholmen Science Park AB/Closer, Sweden. Their "SENDSMART" report is based on field testings in the city of Gothenburg, Sweden and indicate a 5-7 dB reduction. Source: Sendsmart D.nr. [2012-02392] - 2014-1015. A reduction of 6 dB means that only 25% of the original noise remains. Every 3 dB reduction equates to half the noise level.

Banke E-PTO systems can be delivered with a double-chamber pump or a load-sense pump. The double pump is of a special type which is close to noiseless at higher rpm of the electromotor. In principle, the body hydraulics determine the type of pump that is mounted on the Banke system as in most cases, both hydraulic systems are required to work in parallel. In this case the refuse body or crane can always be powered the classical way in case the battery pack is emptied before the tour is completed. The LS pump can only work with a load-sense hydraulic body system and has the capability of providing more system pressure. Cranes normally require more system pressure then the noiseless double pump can provide. Cranes using an E-PTO must therefore always be specified with load-sense hydraulics. The load-sense pump has an additional feature that prevents the electromotor from over-torqueing. Crane movements on low pressure benefit from full oil flow, whilst flow is automatically reduced when high pressure is required. Special combinations are available. Like a tandem arrangement of Load-sense pump and fixed flow pump. Or a closed-loop Load-sense pump coupled with a fixed flow pump. These combinations are however not available on the CM series due to space limitations in the Power-box.

This figure originates from the final report of the Danish Transport and Construction Agency. The figures are based on a combination of two years of field testings and laboratory testings under controlled conditions

The Banke system powers the body work functions independent of the chassis engine. The engine can therefore be switched off and this saves an additional 2.4 litres of diesel per hour (or 2.4 nm3 of CNG per hour). Please consult your chassis dealer for any restrictions on start/stop.

There is a practical limit to the size of any battery pack. Not only because of the costs but also due to the weight and dimensions. Some applications like mobile cranes can demand more energy than a real-world battery pack can deliver. Some combinations of chassis, maneuverability in city centres and weight restrictions can also limit the available space or size for batteries. For those applications, Banke supports recharging during drive.

Recharging during driving with a generator is available for the CM and TM series only. The 3-phase generator from Banke is attached to a chassis PTO which can deliver energy during driving. In practice, it recharges 5 kWh per hour to the battery system. The system is capable to recuperate kinetic energy from the drive train. This however depends on the type of chassis PTO used and possible restrictions of the chassis manufacturer.

With 700 Volt, you can make 400 Volt AC and that allows us to use a highly efficient and low weight permanent magnet electromotor. Higher voltage also lowers the current and reduces the losses caused by resistance.

The TM and CM series benefit from the latest development in electromotors that also have a high efficiency when operating on lower voltage levels. These systems are still not as efficient as the E-PTO large but offer significant improvements in other areas. The systems are less complex to control, are lower in weight and easier to service due to the absence of 700 Volt DC in the system.

Lithium Ion has a good energy to weight ratio. The daily energy can be taken along in the battery pack without overloading the vehicle. Lithium Ion can also be recharged between 2000 and 2500 times before the batteries have lost 20% of their initial capacity. There are, however, many chemistries on the market. Banke chooses Lithium Iron Phosphate which may not have the highest energy density. But it is highly stable, can be discharged to low levels on a daily basis and has a stable aging curve.

The on-board charger needs connection to 3 x 400 Volt 3-phase with Neutral and Protective Earth (5 wire) on a 16 Amp group. Depending on the system, the charger can draw 8 or 3 kW.

This depends on the capacity of the battery pack and how far these have been discharged during use. It also depends on the type of charger that is fitted. Charging may take longer at low temperatures as the on-board heating system will first increase the battery temperature before charging commences. Charging may also take longer when the batteries are not charged every day. In this case, the Battery Management System needs time to re-balance the cells.