How To Store Power Tool Batteries
Have you ever wondered how to properly care for and store your power tool batteries to maximise lifespan? Ensuring your batteries’ longevity and optimal performance is not only about how you use them but also how you store them. In this article, we’ll delve into the best practices on “how to store power tool batteries” to keep them in top-notch condition.
Nickel-Cadmium (NiCd) Batteries
Nickel-cadmium batteries, often called NiCd or NiCad, are rechargeable batteries used in various applications for decades, from power tools to emergency lighting. They were among the first widely adopted rechargeable batteries for consumer electronics.
Features and Specifications
Chemistry: As the name suggests, the main active components are nickel and cadmium. The positive electrode (cathode) is nickel hydroxide, and the negative electrode (anode) is cadmium.
Voltage: A single NiCd cell typically has a nominal voltage of 1.2 volts.
Cycle Life: NiCd batteries can typically be recharged and discharged 500 to 1000 times under normal conditions.
Temperature Tolerance: NiCd batteries have a good temperature tolerance, performing well in cold conditions compared to other battery types.
Discharge Rate: They can handle high discharge rates without significant loss in capacity.
Self-Discharge: NiCd batteries have a relatively high self-discharge rate, losing up to 10% of their charge in the first 24 hours after charging and then up to 10% a month after that.
Density: NiCd batteries have a lower energy density than modern batteries like NiMH or Li-Ion, meaning they are bulkier for the same energy storage.
Environmental Concerns: Cadmium is a toxic heavy metal. This has led to regulations and directives, like in the European Union, where selling NiCd batteries for most consumer applications has been prohibited due to environmental concerns. They are still used in specific industrial applications.
Storing And Care for NiCd Batteries
Memory Effect: NiCd batteries’ most widely known characteristic is their “memory effect”. If a storm is repeatedly only partially discharged before recharging, it “forgets” that it has the rest of its capacity. In essence, its power seems reduced. To counteract this effect, it’s recommended to periodically fully discharge NiCd batteries before recharging them.
Storage: Store them in a cool, dry place. While they have a robust temperature tolerance for operation, prolonged exposure to high temperatures can still reduce their lifespan.
Charge State: Keep them partially charged if you’re storing them for an extended period. Aim for about a 40-60% charge. This can help prolong the battery’s overall life.
Charging: Always use a charger specifically designed for NiCd batteries. Using the wrong charger can lead to overcharging, reducing the battery’s life and potentially causing safety hazards.
Disposal: Due to the toxic nature of cadmium, it’s essential to dispose of NiCd batteries properly. Many regions have specific recycling programs for NiCd batteries.
Thus, while NiCd batteries have been surpassed mainly in consumer electronics by newer battery technologies, they still hold relevance in specific applications due to their robustness and high discharge capabilities. Proper care and understanding of their characteristics can maximise their lifespan and performance.
Nickel-Metal Hydride (NiMH) Batteries.
Features and Specifications
Chemistry: NiMH batteries have a positive electrode (cathode) of nickel hydroxide, similar to NiCd batteries. However, their negative electrode (anode) is a metal hydride, usually made of a combination of alloys.
Voltage: A standard NiMH cell has a nominal voltage of 1.2 volts, the same as NiCd cells.
Energy Density: NiMH batteries offer a higher energy density than NiCd batteries. This translates to more power storage in a similarly sized package, making them preferable for many portable devices.
Cycle Life: They have a decent cycle life, generally offering between 500 to 1,000 charge cycles, depending on the quality of the battery and usage conditions.
Self-Discharge: Earlier NiMH batteries were known for having a high self-discharge rate, but newer “low self-discharge” NiMH batteries, often referred to as “pre-charged” or “ready-to-use”, retain their charge for much longer.
Environmental Impact: NiMH batteries are more environmentally friendly than NiCd batteries since they don’t contain toxic cadmium. However, like all batteries, proper disposal or recycling is essential.
Temperature Sensitivity: NiMH batteries can operate in a wide range of temperatures but are more susceptible to heat-related performance degradation than NiCd batteries.
Storage And Care for NiMH Batteries
Memory Effect: NiMH batteries are less prone to the memory effect than NiCd batteries but aren’t entirely immune. The capacity can appear reduced over time for applications where the battery is consistently used for short durations and then recharged (like cordless phones). It’s a good idea to occasionally fully discharge them before recharging.
Storage: Like NiCd batteries, NiMH batteries should be stored in a cool, dry place. If you plan to keep them for an extended period, aim for a 40-60% charge state. This can help in prolonging the battery’s overall life.
Charging: Always use a designated charger for NiMH batteries. Overcharging can lead to reduced lifespan, potential swelling, or even rupture in extreme cases. Some modern chargers are designed to detect full charge and switch to a trickle charge mode to avoid overcharging.
High-Drain Devices: NiMH batteries perform exceptionally well in high-drain devices due to their high energy density and discharge capabilities. Devices like digital cameras, which can deplete alkaline batteries quickly, can benefit significantly from NiMH batteries.
Hence, NiMH batteries have become popular in many applications due to their increased energy density over NiCd and their more environmentally friendly composition. Proper care, understanding of their characteristics, and using suitable chargers can ensure they deliver optimal performance over their lifespan.
Lithium-Ion (Li-Ion) Batteries
Features and Specifications
Lithium-Ion (Li-Ion) Batteries: Lithium-Ion (Li-Ion) batteries are prevalent in modern electronics due to their high energy density, lightweight nature, and long cycle life. They power various devices, from smartphones and laptops to electric vehicles. Li-Ion batteries do not suffer from the “memory effect” seen in other battery types, meaning they don’t need total discharges before recharging. However, they require careful management to avoid overcharging and extreme temperatures, which can reduce their lifespan and pose safety risks.
- Chemistry: Li-Ion batteries have a lithium cobalt oxide (LiCoO2) cathode and a graphite anode, although there are variations with different materials for the cathode like lithium iron phosphate (LiFePO4), lithium manganese oxide (LiMn2O4), and others.
- Voltage: A single Li-Ion cell has a nominal voltage of 3.7 volts, much higher than NiCd or NiMH cells.
- Energy Density: Li-Ion batteries have a very high energy density, making them ideal for lightweight and compact applications like smartphones and laptops.
- Cycle Life: The number of charge cycles for Li-Ion batteries usually ranges from 300 to 500 complete charge cycles, though this can vary based on usage and the quality of the storm.
- Self-Discharge: Li-Ion batteries have a relatively low self-discharge rate compared to NiCd and NiMH batteries.
- Temperature Sensitivity: Li-Ion batteries are sensitive to high temperatures. Prolonged exposure can accelerate capacity loss. On the other hand, charging at too low a temperature can be harmful.
- Protection Circuitry: Most Li-Ion batteries have built-in protection circuits to prevent overcharging, over-discharging, and overheating.
- Variants: There are several types of Li-Ion batteries based on their cathode materials. For instance, LiFePO4 (Lithium Iron Phosphate) batteries are known for their safety and long cycle life. In contrast, LiPo (Lithium Polymer) batteries, a subset of Li-Ion, have a pouch format and can be thin and light.
Storage And Care for Li-Ion Batteries
Temperature: Avoid storing or charging them in extreme temperatures. They are especially vulnerable to heat, leading to accelerated capacity loss or pose safety risks. Cold temperatures, especially during charging, can also harm the battery.
Charge State for Storage: If you plan to store a Li-Ion battery for an extended period, it’s best to keep it at around 50% charged. Storing it fully charged for prolonged periods can reduce its overall lifespan.
Charging: Use chargers designed explicitly for Li-Ion batteries. Overcharging can be hazardous and lead to reduced battery life or thermal events. Many devices with Li-Ion batteries have built-in circuits to prevent overcharging.
Physical Inspection: If a Li-Ion battery swells, becomes hot, appears damaged, or leaks, it should not be used or charged. These can be signs of internal short circuits or other failures, which can be dangerous. Proper disposal at a battery recycling centre is essential.
Deep Discharge: Unlike NiCd batteries, Li-Ion batteries do not benefit from being fully discharged. Letting them release entirely too often can harm their lifespan.
Thus, Lithium-Ion batteries dominate the consumer electronics market due to their high energy density and lightweight nature. Proper care ensures they remain safe and maintain their performance over time.
Lithium Polymer (LiPo) Batteries
Lithium Polymer (LiPo) batteries are more common in the RC (remote control) hobbyist realm and some specialised gadgets due to their distinct advantages over traditional Lithium-Ion cells. Here’s an in-depth look at their features and specifications:
Features and Specifications
Chemistry: LiPo batteries use a polymer electrolyte instead of a liquid one in conventional Lithium-Ion batteries. This allows them to be packaged in a soft, flat pouch rather than a rigid cylindrical or prismatic cell.
Voltage: A single LiPo cell has a nominal voltage of 3.7 volts, similar to other Lithium-Ion cells. However, when fully charged, the voltage typically reaches 4.2 volts, and it’s considered discharged at around 3.0 volts.
Energy Density: LiPo batteries have a slightly lower energy density than standard Lithium-Ion batteries. However, this is often offset by their versatility in shape and lightweight properties.
Flexibility in Shape and Size: One of the main advantages of LiPo batteries is their adaptability. They can be made thin or into irregular shapes to fit the specific requirements of various devices, making them especially popular for mobile gadgets, drones, and RC vehicles.
Weight: LiPo batteries are often lighter than conventional Lithium-Ion batteries with similar capacities.
Discharge Rate: LiPo batteries are renowned for their high discharge rates, a critical feature for applications like RC cars and drones, where bursts of power are required.
Cycle Life: The cycle life of LiPo batteries varies but tends to be shorter than traditional Lithium-Ion batteries. A LiPo battery typically offers 300 to 500 charge cycles, depending on the usage, quality, and charging conditions.
Self-Discharge Rate: LiPo batteries have a self-discharge rate comparable to other Lithium-Ion batteries, which means they retain their charge relatively well when not in use.
Storage And Care for LiPo Batteries
Storage Voltage: Storing LiPo batteries at approximately 3.8 volts per cell or about 50% charge is crucial. This helps maintain the battery’s health and longevity.
Physical Integrity: Due to their soft pouch construction, LiPo batteries are vulnerable to punctures, crushing, or other physical damage. Any compromise in their integrity can lead to dangerous situations.
Swelling: The swelling of a LiPo battery indicates gas buildup inside, which is a sign of internal damage or failure. Such batteries should not be charged or used and must be appropriately disposed of.
Charging Safety: Always use a LiPo-safe bag when charging. These bags are designed to contain any fire or explosion that might occur in the rare event of a battery failure during charging.
Temperature Sensitivity: LiPo batteries are sensitive to extreme temperatures like other Lithium-Ion batteries. Both charging and storage should ideally happen at room temperature. Exposure to high temperatures can accelerate degradation, while cold temperatures can hinder performance.
Over-discharge: Never allow a LiPo battery to be discharged below its minimum safe voltage (typically around 3.0 volts per cell). Over-discharging can irreversibly damage the battery.
In summary, while LiPo batteries have certain advantages in flexibility and weight, they also demand meticulous care and handling. Their unique characteristics make them especially suitable for specific applications, but users must be well-informed and cautious to ensure their safe use and prolonged lifespan.
Improper Storage Causes Negative Impact On Batteries
Improper care and storage of batteries can lead to various adverse outcomes, some of which can be hazardous. Here are the potential consequences:
Reduced Lifespan: Batteries stored or misused can have reduced charge cycles, meaning they will only last for a while before they need replacement.
Decreased Performance: A battery might not hold its charge as effectively or might provide power inconsistently, causing the device it powers to malfunction or shut down unexpectedly.
Leakage: Batteries, especially older alkaline types, can leak acid or electrolyte. This corrosive substance can damage the device they’re stored in and pose a risk to the user handling them.
Swelling: A battery can swell up, Especially in Lithium-Ion and lithium-polymer batteries, due to gas buildup inside. This is typically a sign of battery failure and can cause physical damage to devices, incredibly tightly packed ones like smartphones.
Corrosion: Battery terminals can rust over time, especially if exposed to moisture or if the battery leaks. Corroded terminals can lead to poor connections and reduced performance.
Memory Effect: As seen in Nickel-Cadmium (NiCd) batteries, repeated partial discharging can cause the battery to “remember” a reduced capacity, leading to shortened run times.
Explosion or Fire: In extreme cases, especially with Lithium-based batteries, improper care (like punctures, extreme temperatures, or using the wrong charger) can cause thermal runaway, leading to an explosion or fire.
Environmental Harm: Improper disposal of batteries can be harmful to the environment. Many batteries contain toxic chemicals that can leach into the soil and groundwater if thrown away with regular trash.
Economic Impact: Replacing damaged or worn-out batteries more frequently due to improper care can become expensive over time.
Physical Harm: In some cases, especially with larger batteries or those in critical devices (like medical equipment), battery failure can lead to physical harm or endanger life.
To avoid these consequences, it’s essential to follow manufacturer guidelines for using, storing, and disposing of batteries. Proper battery care ensures the safety of both the user and the devices the batteries power.
In conclusion, batteries can offer long, reliable service when cared for and stored correctly. Understanding their characteristics and needs is critical to maximising their potential and ensuring safety. Some knowledge and precautions can go a long way, whether using them in daily devices or more specialised applications.
How often should I charge my power tool batteries?
Charge them when they are near depletion. Frequent short charges can reduce their lifespan.
Can I store my batteries in the garage during winter?
Cold temperatures can harm battery performance. Storing them in a cool, dry place away from extreme temperatures is best.
Is it safe to store batteries near other metal objects?
No, metal objects can short-circuit the terminals. Store batteries away from any metallic items.
How long can I store a fully charged power tool battery?
It’s best to store batteries at 50-60% charge for long-term storage. A fully charged battery can lose its capacity faster when stored for extended periods.
Do old batteries affect the performance of the power tool?
Yes, as batteries age, their ability to hold charge decreases, which can reduce the tool’s performance. Regularly check and replace old batteries.