Begin with the following:
1. Determine the lift truck manufacturer’s battery requirements. For some trucks, you may be able to choose either a 36 or 48-volt battery and charger set. Other trucks, intended for hazardous environments, require a special battery rated EE or EX. Check the battery weight range specified for the truck and meet this specification to provide adequate lifting counterweight.
2. Decide whether the application requires a new, full capacity battery. If the user does not operate the truck for a full, hardworking shift, a used battery may be an option.
Battery Selection Pointers
If a used battery is what you need, you can proceed to the next checklist:
1. If you already have a charger that you intend to use with an electric truck, review its name plate data to make sure that it is indeed suitable. Its rating will have to match the battery’s nominal (as manufactured) ampere– hour capacity. If it is difficult to find a used battery that matches the existing charger, you may find it economical to negotiate a charger swap with your battery supplier. Always make sure that battery and charger match up in all specifications.
2. Determine how much the lift truck will be used between charging. Always allow time for a full eight-hour charge. Many used batteries are available that still have years of service left in them – although at a diminished capacity. Figure the operating time of the truck as a percentage of the truck’s workday (six hours of truck run time = 100%) and find a used battery with a percent remaining capacity that matches.
3. After battery voltage, weight requirements and dimensions (measure interior of battery compartment rather than the existing battery), determine other physical requirements. Does the battery case require a steel lid? What style connector is required? What is the length and position of the battery cable set?
Used Battery Guidelines
After all other specifications have been met, inspect the used battery that you intend to buy. If age can be determined, this may be useful information, but consider this in context with other battery factors. Some batteries have been known to provide acceptable service for more than 10 years, while others, due to abuse or deficiencies in design, fail after two or three years.
Use the following checklist to help in your determination of used battery quality:
1. Complete a full– scale capacity discharge test that shows on-charge voltages as
well as hourly readings of cell voltages under proper load at the six– hour rate. The constant current test load that should be used is battery ampere hour capacity divided by 6. The test reveals battery capacity by measurement of individual cell voltages under load. A 100 % capacity battery shows 1.72 volts per cell at the end of 6 hours under load. Cells that reach this voltage earlier in the test are correspondingly less that full capacity.
2. Inspect the mechanical condition of the battery case. Is it badly eroded due to corrosion? Look carefully at the lifting ears to see that their strength has not been compromised. Also, try to see if the steel case bottom is intact. Either of these areas can cause safety problems when lifting the battery, for delivery or installation.
3. Look at the cell covers and check for cracks that may allow acid spray to promote corrosion during battery use. Do not put a battery into service that is not properly sealed.
4. Battery cables should be intact without any bare copper conductor revealed. A cable with cut insulation can arc when it comes in contact with connector straps on top of the battery. This can cause an explosion.
5. After a full equalizing charge, use a hydrometer to check specific gravity of each cell. Readings should reach 1.280. Variation should not exceed 20 to 25 points. If specific gravities vary by more than this, either individual cells have failed to come up to a full charge, or acid dilution has occurred. In either case, the battery needs attention before it can enter service.
Here is a master checklist:
- Check the truck manufacturer’s battery requirements.
- Can the truck owner operate with a used battery?
- If you already have a charger, make sure it matches the battery.
- How much battery capacity does the user need?
- Measure compartment size, note connector type, cable position and length.
- Does the battery require a lid?
- Get discharge test results on the used battery you are considering.
- Inspect the battery case for severe corrosion damage.
- Check for cracks on top of the battery.
- Make sure cables and connectors are intact.
- Check for uniform specific gravity in all cells.
These guidelines can help make your work with electric lift trucks a little easier, but the best assurance of used battery quality and compatibility comes with dealing with an experienced, reliable battery shop. Their expertise can simplify your electric truck concerns and let you concentrate on your business.
For more information, contact Arcon Equipment Inc. (440) 232-1422.