Proper care and routine maintenance are essential to getting the best performance from your forklift batteries. Unfortunately, dirty or corroded terminals can significantly reduce their lifespan. Here’s how to spot the signs of bad battery terminals, so you’ll know when it’s time to replace your forklift batteries.
By design forklift batteries are large and heavy devices. They power the entire forklift to handle heavy lifting and proper placement and act as a counterbalance to stabilize the vehicle under substantial loads.
What are forklift battery terminals?
Forklift battery terminals serve as the connection point between the battery and the forklift’s electrical system. Each battery has two terminals: the positive terminal, indicated by a plus sign (+), and the negative terminal, marked with a minus sign (-).
When the forklift is in operation, electrical energy flows from the positive terminal to power the motor, hydraulic system, and other components, enabling the machine to move, raise and lower loads, and various functions. The circuit is completed as the energy returns through the negative terminal. During charging, this process is reversed to restore the battery's power.
Clean terminals ensure efficient energy transfer and smooth operation. However, dirt or corrosion on the terminals increases electrical resistance, potentially leading to significant performance issues.
Bad Battery Terminal Symptoms
It doesn’t matter whether the issue is with the positive or negative terminal. The symptoms of a faulty positive battery cable are similar to those of a damaged negative battery cable.
Decreased Performance
Decreased performance is one of the most common signs of a bad battery terminal. Common indicators include:
- Slow acceleration: A common early sign of faulty battery terminals is the forklift taking longer than usual to reach its desired speed.
- Reduced lifting capacity: The forklift might struggle to lift loads it previously handled with ease.
- Shorter runtime between charges: Inefficient power transfer can drain the battery faster, increasing downtime between charges.
- Inconsistent performance: Faulty terminals may cause intermittent connections, making it harder for the operator to maintain control.
- Frequent stalling: Bad battery terminals can trigger voltage drops or sudden interruptions in the electrical supply, causing the forklift to stall or shut down unexpectedly.
- Dim or flickering lights: Bad connections can affect lighting, reducing visibility and safety.
- Unusual noises: Electrical arcing or sparking from damaged terminals may cause strange sounds “under the hood.”
Corrosion Buildup
Corrosion is the buildup of gunk on battery terminals, caused by chemical reactions inside the battery producing lead sulfate crystals. Corrosion creates an insulating layer that disrupts the flow of electricity between the terminals and cables.
Corroded battery terminal symptoms include:
- White or greenish powder: Often lead sulfate, but it could be another byproduct of corrosion
- Flaky or crusty deposits: the terminals may appear irregular or rough to the touch.
- Discoloration: Metal may appear dull, dark, or blackened.
- Buildup around terminal clamps: Corrosion may spread to the clamps securing the cables.
Additional symptoms include shorter battery runtimes (due to electricity leaks), excessive heat, and flickering lights.
Sulfation
When a battery is undercharged or not fully charged, hardened lead sulfate builds up on the lead plates inside the battery. This process, called battery sulfation, worsens with each use. While the damage isn’t visible without opening the battery, its effects are noticeable.
Some everyday performance issues of sulfation include:
- Reduced runtime.
- Inability to hold a charge.
- Longer charge times due to increased internal resistance.
- Difficulty starting.
- Low battery voltage.
- Winter conditions naturally lower a battery's capacity, and when sulfation is also present, performance takes an even bigger hit.
- Corrosion.
- Bulging or swollen battery case, indicating severe damage.
These symptoms highlight the importance of maintaining proper charging practices to prevent sulfation.
Loose or Damaged Connections
The forklift’s entire electrical system relies on two cables connecting to the battery’s positive and negative terminals. All it takes is for one or both of those connections to become loose, and it can disrupt the electrical current throughout the forklift.
Loose connections often result from everyday wear and tear caused by a forklift’s near-constant movement and vibrations during daily use. Additionally, working in dusty, dirty, or damp environments can weaken these connections over time. Ironically, overtightening the terminal clamps can also damage connections, causing the cables to fit improperly.
Common bad battery connection symptoms include:
- Unstable power: Loose battery terminals cause erratic forklift behavior, including unexpected shutdowns.
- Battery drainage: The battery may lose charge even when not in use.
- Heat generation: Loose connections can create “hot spots,” potentially damaging nearby components such as terminals, cables, and other components.
- Voltage drops: Current trying to pass through a loose connection can result in insufficient power reaching the forklift’s electrical components, resulting in poor performance.
Spilled Acid
A bad battery terminal can lead to acid buildup on the exterior of the battery. Corrosion or loose connections may create gaps between the terminals and cables, allowing acid to leak, especially when the forklift is in use and the battery is vibrating. Damaged terminals, perhaps due to overtightening, can also cause acid leaks. Finally, if the terminal clamps are not secure, they may allow acid to leak from the terminals.
Battery acid is a highly corrosive and toxic substance posing significant risks to both equipment and people. If acid spills from a forklift battery, it requires immediate attention and safety precautions. If you are not adequately trained or equipped to handle the cleanup and disposal, it's crucial to contact a professional hazardous materials team. Always prioritize safety when dealing with hazardous substances.
Excessive Heat Generation
Overheating terminals pose several safety concerns, primarily the potential for fire. Excessive heat can cause battery acid to vaporize, releasing flammable gases. If this gas builds up in the battery compartment, it can result in a fire or worse, an explosion. Several factors contribute to excessive heat generation, including:
- High electrical resistance: A faulty battery terminal can cause energy to be lost as heat.
- Overcharging: When the battery is overcharged, it releases more energy than it can handle, resulting in heat buildup.
- High current draw: Heavy loads or prolonged usage can cause a forklift to draw a higher current from the battery, increasing heat at the terminals.
- Internal battery problems: Damaged cells or faulty internal connections can cause the terminals to overheat.
Continued overheating can cause terminal and component damage, potentially melting parts of the electrical system. This not only shortens battery life but jeopardizes the forklift operator’s safety.
Difficulty Starting
When bad battery terminals impact the electrical system, one major function of the forklift is often compromised: starting. Instead, a clicking sound may be heard, indicating the electrical current isn't reaching the starter motor properly.
A forklift that won’t start majorly affects overall warehouse productivity. When the machine is unable to perform its necessary tasks, the operator and other personnel are diverted to troubleshooting to repair the situation.
Preventing a Bad Battery Terminal
Staying ahead of the situation with routine maintenance is one of the best ways to avoid issues caused by bad battery terminals. Setting up a regular inspection schedule for corrosion, loose connections, and other potential problems can help avoid major issues. Forklift operators should visually inspect battery terminals before each shift and conduct a more thorough inspection weekly or as recommended by the manufacturer. If you're unsure about any aspect of inspecting, cleaning, or repairing the forklift battery terminals, consider implementing a preventive maintenance program to maximize battery performance.
As part of regular maintenance, be sure that the battery terminals are clean and free of debris. If you notice corrosion beginning to build up, clean and neutralize the affected areas. Always wear personal protective equipment (PPE) like acid-resistant gloves and safety goggles, and keep a fire extinguisher nearby in case of emergencies. Always avoid direct contact with battery acid. If battery acid contacts your skin, immediately wash the affected area with water and seek medical attention.
Acid can be neutralized by using a mixture of baking soda and water (the ratio is typically one tablespoon of baking soda per cup of water). Commercial battery terminal cleaners are also available. Clean the terminals with a nylon brush to remove corrosion. After cleaning, make sure the terminals are completely dry before reconnecting the cables. Ensure the terminals are tight, but avoid overtightening to prevent damage.
Work in a well-ventilated area to ensure that any fumes generated during cleaning can disperse safely. Do not allow the baking soda solution (or professional cleaning product) to enter the battery cells. It can dilute the battery’s chemicals and negatively affect its performance.
If you notice terminals that are cracked, damaged, or corroded beyond repair, they must be replaced. Extensive damage, severe corrosion, or recurring terminal issues despite regular maintenance, may indicate a significant electrical problem that requires professional diagnosis and repair.
Be sure that your staff is properly trained on how to maintain good battery terminal connections. It is the employer’s responsibility to ensure that their staff is trained on proper battery handling, inspection procedures, and safety procedures.
Proper charging practices can also help maintain clean, efficient terminals. Avoid undercharging or overcharging the battery to prevent heat buildup and corrosion. Consider using terminal protectors or terminal caps to shield terminals from moisture, dirt, and other contaminants.
Lastly, using high-quality forklift batteries ensures better performance and reduces frequent maintenance needs. High-quality batteries can withstand the demands of daily forklift operations and are less likely to develop issues.
Using a forklift with faulty terminals can lead to electrical damage and costly repairs. Fortunately, Concentric offers fully managed service offerings that place all battery management duties in the hands of on-site experts. Finding the perfect fit for your needs sets your organization up for success in material handling and guarantees uptime.
We also offer an extensive range of high-quality forklift batteries to meet your replacement requirements. Give us a call at 888-691-8710, or you can complete this form to learn more about our services.