Electric forklifts powered by lead-acid batteries may cost about 3.5 times less on fuel than LPG but that does not mean that electric forklift operators can afford to be blasé over their running costs, which for the careless can prove much more expensive.
Battery companies have incrementally improved battery capabilities and their chargers to reduce costs significantly. These include, for example, Hoppecke’s Trak-Air system which cuts electrical use by over 30% and reduces battery filling requirements from 26 times a year down to 4 times. It also cuts carbon produced by 30%. High frequency Smart charging is another example. This saves on average 18-20% of mains electric use over a conventional 50 Hz charger and more than 30% when coupled to an air circulation battery. But less used and appreciated are the software management programs that can monitor battery use and changing systems to yield much longer battery life. Users should also consider battery suppliers’ full care packages, which can deliver paybacks in under two years.
A “Power for Life” contract from Hoppecke, for example, saved one its clients £165,125 over a 5-year period. Previously, the client used three full time people to change and fill batteries for the 73 assorted lift and pallet trucks in a 24/7 operation. Hoppecke took over responsibility for battery filling, lid cleaning and supply of all de-ionised water. In addition, it also supplied a battery changing and call forward system to allow drivers to safely and quickly change their own batteries correctly, choosing which battery to use. Broken down, the annual savings were £21,687 on battery changing and £11,338 on power consumption, giving a payback of 16 months.
Batteries are a major cost element in any electric forklift and conventional wisdom declares that in a multi-shift operation there should be standby batteries for each truck but a good battery and power management system to oversee all charging and changing operations, like Enersys’s PowerNet, can significantly reduce battery numbers and even upgrades to the power supply infrastructure in the charging area.
One advantage of this package is that it allows operators to manage their charging patterns to take advantage of off-peak rates for lower price electricity. The system runs on a standard PC and is completely configurable in software, so it can be set up with a wide range of user-defined parameters to provide a unique set of performance characteristics. A valued aspect of PowerNet is that the system can shut down chargers supplying batteries requiring the greatest amount of charge at times when available power is low. Power is then allocated to the remaining batteries to ensure they are fully charged as quickly as possible with Powertech HF chargers. Batteries are brought back on line for charging whenever power is available. The chargers automatically detect the battery’s level of discharge and will only supply the amount of power needed to restore full charge.
Another benefit of PowerNet is that a display in the charging areas shows the order in which batteries should be retrieved for each type of truck. This overcomes the problem of drivers taking the nearest available battery, regardless of its true state of charge.
Using such a system, John Lewis found that at its 800,000 ft2 Magna Park distribution centre using 50 warehouse trucks over extended shifts it needed only a 60% spare battery capacity, or six spares for every 10 trucks and avoided a £100,000 additional power supply infrastructure to the charging area.
Most battery customers are fully aware of exact fuel costs for running their road transport fleets but many have very little idea of the real cost of operating their materials handling requirements. Leading battery suppliers provide an energy audit to prospective clients to help them avoid committing to a lengthy contract that could cost them far more than is necessary. In recessionary times most of all, electric forklift truck users should pay more attention to smart battery management programs.
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