A battery charging room strategy is needed to see that battery charging requirements are not ignored in the rush to meet other production goals. The following plan is a simple outline that provides for proper use, handling, and re-charging of electric lift truck batteries in one customer’s s 2-shift operation.
The goals:
- Full utilization of all lift trucks at all times through “on demand” battery charging and rack charging.
- Minimum use of space and man-hours, and low lift truck traffic in the battery charging area, through rack charging.
- Safeguarding of valuable battery investment by providing ideal battery conditions that maximize battery life and support manufacturer’s s recommendations (thereby protecting warranty coverage).
Demand Charging Benefits When forklift operators change out and place their lift truck batteries on charge at the indication of a “low battery” signal from a battery discharge indicator truck gauge, they are supporting the best strategy for efficiency in a multi-shift operation. Under this system, batteries are removed from the lift trucks and tucked away on racks for charging, and trucks are in and out of the area with a fresh battery in a matter of minutes. This means that parking space for a large number of lift trucks in the battery room is not necessary. Trucks can be left in their designated work area during shift change or off hours – employees avoid wasting time returning or picking up the truck from the charging area when they leave or arrive at the workplace. This is accomplished by dedicating two batteries to each truck, one of which is on the charging rack at all times. The typical changeout and charging cycle begins with the truck operator seeing an indication of a “low battery” on his lift truck battery gauge. Within 15 minutes, the truck’s s lift interrupt circuit will disable the lifting mechanism to ensure that the driver does not over discharge the battery. At this point, the lift truck can be driven to the battery changing and charging area. Using a portable battery transfer cart, or hoist, the driver, without assistance, can quickly exchange his truck battery for a fully charged battery from the rack. The discharged battery is placed on the rack and connected to a charger for an uninterrupted 8-hour charge. A weekly equalizing charge for each battery (an 11 to 12 hour extended charge – every Friday for example) is also handled in the same way. Importantly, because the lift truck batteries are brought out into the open for charging, routine maintenance tasks such as watering and cleaning are facilitated. The benefits of improved truck availability and proper battery cycling provided by this “charging on demand” system remain in effect despite any changes that may occur in workload, duty cycle, and number or lengths of shift. Because the charging schedule is determined by the battery requirements alone, no one needs to make up a battery charging schedule.
Protecting Your Battery and Lift Truck Investment Under this plan, electric forklift batteries have an excellent chance to receive proper cycling – without harmful undercharging or over-discharging. Electric forklift batteries are “deep cycle” industrial lead acid batteries that must receive a full 8-hour charge after a work cycle that discharges the battery to its “80% discharge ” level (the “low battery” point indicated by lift truck panel gauges and lift interrupt circuits). Any deviation from this charging protocol such as pulling batteries off the charger after only an hour or two of charge, or running the battery completely “dead”, has a damaging effect that shows up in premature battery aging. Improper battery charging also voids the manufacturer’s warranty under the “abuse” exclusion. Operating a lift truck with a battery that is over discharged is harmful to truck electrical components. Low voltage operation is known to overheat truck control circuits, relay contacts, and motors. Too much charging is unwise as well. This battery management plan is designed to prevent battery abuse and its effects on efficient lift truck operation, as well as significantly improve the availability of fully charged lift truck batteries during all work shifts.
Implementation Requirements:
- Outfit battery charging area with appropriate hoists, transfer carts and racks to allow quick and safe changeout of truck batteries.
- Ensure that a spare battery is available for every truck that must work two full shifts.
- Equip lift trucks with battery discharge indicator gauges and lift interrupts.
- Clearly designate (stencil) each lift truck’s s battery set to ensure that the operator exchanges with only the battery specified for his truck. (In operations with a large number of identical batteries, this allows the operators to keep track of batteries with recurring problems, and flag them for maintenance or warranty attention. It also ensures that the battery being taken off the rack has had a full charge and a cooling off period.
For more information, contact Arcon Equipment Inc. (440) 232-1422.
