Interest is high in reducing battery maintenance time?
This is reflected in some forklift owners’ interest in the newly available sealed “maintenance-free” style batteries. These batteries are finding customers despite factors such as very limited field experience for this technology in deep-cycle industrial use, high cost, and a requirement for special chargers that take hours longer to charge than conventional systems. At considerably less cost, many forklift owners are equipping their standard lead-acid batteries with watering systems that meet the goal of reduced maintenance without sacrificing charging time or potential battery life.
Currently, nothing matches the conventional “flooded” lead-acid cell for cost-effective long life in heavy duty applications. This battery type does not require the regular addition of plain water to replace that lost due to evaporation and electrolysis. A battery in good condition operated at normal temperatures is a very low-maintenance power package that does not use large quantities of water, but occasional monitoring is necessary. In some applications battery watering will be required weekly, in other situations watering sessions may be less often.
The most basic approach to battery watering involves nothing more than a handheld water container or hose. The operator removes all cell vent caps, judges electrolyte level by eye, manually adds water, and replaces all vent caps. In some plants this is considered a safety issue as well as time-consuming. This manual approach does require that the battery be out in the open for easy viewing of the electrolyte level during filling. Battery watering systems have been developed that effectively address these concerns.
Watering system plumbing (installed on top of the battery) is composed of valve-equipped filler caps (which replace the standard cell vent caps) and tubing that connects the caps to the water supply through a quick-connect fitting which can be accessible from outside of the battery compartment. Filler caps must stop the flow of water reliably so that each cell maintains the proper electrolyte level.
Filler caps may have float mechanisms of varying degrees of complexity that provide level control, or may accomplish the same result with designs that use no visible moving parts. Those caps with unprotected floats must be handled more carefully during installation or when removed from the battery.
Hooking up: Different methods Different battery watering systems accomplish the same ends by different means. In some designs water is supplied by a gravity-feed tank suspended above the battery charging area. In other systems, a garden hose with a quick-connect fitting uses the local water pressure to fill the battery, via a regulator, through the watering system plumbing. The filling method is not interchangeable— each system must be designed to accommodate the specific flow/pressure characteristics of the water supply method used.
Each approach has its advantages, for example a system that fills the battery directly from the local water line or from a pump-pressurized tank has the potential to be a much faster fill method than a gravity-feed system. Systems that operate at lower pressures may have simpler, more flexible, tubing connections on top of the battery. A gravity fill or pump-equipped tank system can be used to dispense purified water in those rare cases where local tap water is unsuitable for battery watering due to very high mineral content. (In-line water deionizers are also available for tap water hose systems). Some see an advantage in a cart-mounted, pump-pressurized tank that can be moved easily to water batteries at any point in the plant.
The battery watering procedure is simple with any of those systems in place. Connect the single point watering fitting to the water supply. High pressure/flow systems bring the battery electrolyte up to the proper level in seconds, gravity-fill or low-pressure systems can take several minutes.
Pressure and flow is not an issue in one fully automated system that is routinely connected to its water supply at the same time the battery is plugged into its charger. A control box mounted next to the charger starts water flow to the battery at an appropriate time late in the charging cycle, and batteries end up with both charge and electrolyte topped off.
Regular attention still needed
Attention to the battery and its electrolyte status is still required on a regular basis. No battery watering system is entirely fail-safe. Over time, there is always the possibility of individual failure of a valve cap or its connections— which can result in either starving or overfilling a cell. An additional port can be installed in each cell cover to give the operator quick access with a hydrometer without disturbing the watering system. Such access is an important part of any watering system— it allows quick verification that the water level is correct in each cell. And remember, hydrometer readings are vital measurements that can reveal problems before they cause major downtime.
Hands-on: Cheaper, less plumbing
Let’s not forget the simpler approaches to battery watering that require less up-front investment. Automatic shut-off hose nozzles are wielded by the operator the same way one would use a garden hose nozzle at home. Although the water flow shuts off automatically at the proper level without the need to stand directly over the battery to eyeball the level in the cells, the operator must still remove each vent cap and replace it- if he is using conventional vent caps on the battery. Aftermarket vent cap designs that permit filling without removal are available in two forms, a flip-top design, and a cap that features a slit rubber membrane.
For more information, contact Arcon Equipment Inc. (440) 232-1422.
