April 9, 2018: TPPL battery manufacturer EnerSys has expanded its NexSys range of batteries for forklift trucks and automated guided vehicles, the firm announced on March 19.
AGVs are portable robots that follow wires or other guidance markers along floors in warehouses, or sometimes navigate by laser or magnet.
The NexSys 2-volt TPPL cells are built using pure lead plates that are much thinner than lead calcium/antimony grids, allowing many more electrodes to be fitted in the same space, increasing battery capacity and boosting power density.
The new range includes taller (370-675mm) cells, which means volume and capacity are increased, and because they can be charged over brief periods like rest breaks or even shift changes, the vehicles are in use virtually continuously and do not have to be parked to recharge or have their batteries removed while doing so.
Anssi Laitinen, senior director marketing EMEA at EnerSys Motive Power said the use of lithium batteries in industrial trucks, which was currently less than 2%, was bound to rise, especially when the price dropped as a result of the boom in electric car use.
“The share of lithium-ion technology is likely to rise in particular with small, manually operated industrial trucks with little space available in the equipment,” he said.
Lead acid, he said, would continue to score well in the heavy-duty sector.
“Modern advancements, such as TPPL batteries or the square tube design, can enable lead acid batteries to meet more stringent demands in the intralogistics sector for productivity, flexible charging and performance,” he said.
Laitinen said the complexity of lithium batteries meant there was more risk associated with the technology. The electronics within them, he said, meant the risk of faults and outages was far higher, and this unreliability came at the cost of greater technical complexity.
“A common aspect of all types of lithium-ion cells is that they are more sensitive to certain operating conditions and external factors than lead-acid batteries,” he said, which meant that they needed a battery management system to monitor charging and discharging.
“This BMS usually has a direct interface to the electric vehicle. A consequence of this close integration of lithium ion batteries into the vehicle electronics is that most industrial truck manufacturers make and install their own lithium ion battery systems.
“Manufacturers are reluctant to give external parties access to the CAN bus (controller area network) of their forklift trucks – a prerequisite for integrating batteries from ‘independent’ suppliers. For operators of industrial trucks, this means they have to buy their lithium ion batteries from the equipment manufacturer, not from the manufacturer of their choice.
“By contrast, lead acid batteries from different manufacturers are mutually compatible, so a wide variety of vehicles can be equipped with batteries from a single supplier.”
Laitinen also said the sustainability of lead batteries (which contain chiefly lead, sulphuric acid and plastic) meant they were almost completely recyclable, whereas lithium batteries first needed a chemical analysis before even recycling was even considered.
“The difficulty of recycling is also indicated by the target stated in the EU Battery Directive (2006/66/EC) – one of the most advanced recycling directives in the world – which sets a goal of just 50% by weight for lithium batteries,” he said.
The new batteries are available in standard and fast configurations so the right combination of battery, charger and monitoring system can be specified, the company says.