Battery Chargers

A battery charger is a device designed to push electrical energy through a secondary cell or a battery to recharge it. The specific voltage, current, and termination methods are dependent on the battery's chemistry and construction, as different battery types have unique charging requirements.

How Battery Chargers Work

A typical rechargeable battery can be charged many times. Once a current starts to flow into a depleted battery, the electrodes are recharged, and the battery's energy is restored. It’s important to cut off charging once the maximum capacity is reached. Overcharging causes batteries to expand excess energy, leading to overheating, which can result in rupture, chemical leaks, or even explosion.

Different types of rechargeable batteries respond best to specific charging methods. Therefore, a battery charger suitable for one battery type may not work well with another. For example, a car battery recharger should not be used for a mobile phone, nor should a NiMH battery be charged with a NiCd charger.

Charging Protocols by Chemistry

Battery chargers utilise distinct protocols tailored to different battery chemistries:

Lead-acid Battery Chargers

Chargers for lead-acid batteries typically employ a multi-stage charging process, commonly including Bulk, Absorption, and Float stages. During the Bulk stage, the charger delivers a constant current until the battery reaches approximately 80% of its full capacity. In the Absorption stage, the voltage is held constant while the current gradually decreases. After reaching full charge, the charger enters a Float stage, delivering a current that’s low enough to counteract self-discharge without overcharging or gassing.

Lithium-based Battery Chargers

Lithium-based battery chargers follow a specific charging protocol, most commonly Constant Current/Constant Voltage (CC/CV). The charger delivers a constant, high current until the battery voltage reaches its maximum set point. Once the maximum voltage is reached, the charger holds the voltage constant while the current gradually tapers down to a minimal level. Many lithium-ion battery chargers also incorporate cell balancing functions to ensure all cells within a multi-cell pack are equally charged, enhancing safety and lifespan.

Nickle-based Battery Chargers (NiCd and NiMH)

NiCd battery chargers use a constant current method and can detect full charge by a slight drop in voltage. They are somewhat tolerant to overcharging at low rates, but prolonged overcharging can cause damage. NiMH batteries are typically charged with a constant current, but the full-charge detection is more critical due to lower tolerance for overcharge. Often, temperature rise is also used as a termination criterion for NiMH batteries.

Features and Benefits of Battery Chargers

Battery chargers offer several advantages:

• Cost-effective: Batteries can be reused multiple times, extending their performance life.
• Eco-friendly: Recharging batteries reduces the number of batteries that end up in landfills prematurely, contributing to environmental sustainability.
• Versatile: Modern battery chargers can serve several chemistries including lithium-ion, NiCd, and NiMH, with universal chargers equipped with algorithms to handle various types.
• Convenience: Some battery charger models offer portability and adapters, allowing for charging on the move, such as in vehicles.
• Efficient and Timely: Charging times typically do not take long, depending on the battery's capacity and the charger's current output.
• User-friendly: Many chargers come with clear indicators, such as lights that change colour, to signal charging status and completion.

Key Characteristics of Battery Chargers

The design and functionality of battery chargers are highly specialised to match the unique characteristics of different battery types. Here's a breakdown of the common types of battery chargers, by feature:

Output Voltage

The output voltage of a battery charger is the voltage delivered to the battery to charge it. This voltage is always higher than the nominal voltage of the battery, as a higher potential difference is required to drive current and reverse any chemical reactions.

Input Voltage

The input voltage refers to the electrical power source the battery charger draws its energy from. This is typically the standard mains (AC) voltage available in a given region, or a DC voltage source in specific applications.

Chemistries Charged

Different battery chemistries have unique charging requirements due to their distinct electrochemical properties. Battery chargers are often designed to be compatible with one or more specific chemistries, and universal chargers are equipped with algorithms to handle multiple types.

Battery Type Charged

Beyond chemistry, batteries are also categorised by their application and form factor. Battery chargers are designed to accommodate these different battery types:

• Automotive batteries
• Small device batteries
• Power tool batteries
• Uninterruptible Power Supplies (UPS) batteries
• Rechargeable household batteries

Essential Considerations for Choosing a Battery Charger

To make an informed purchasing decision, consider the following factors before you buy a battery charger online or in-person:

• Smart vs. Basic Battery Chargers:
  • Basic Battery Chargers: Often simpler and less expensive, delivering a constant current or voltage without advanced monitoring. Suitable for less sensitive battery chemistries or situations where strict control isn't critical.
  • Smart/Intelligent Battery Chargers: Incorporate microcontrollers for optimised charging, multiple protection features, and battery health monitoring. They can often detect battery type, condition, and automatically adjust charging parameters for optimal performance and longevity. They may also feature trickle charge, float charge, or desulfation modes for specific battery types.
• Charging Speed and Current (C-rate): The charging current (often expressed as a C-rate, e.g., 1C means charging at a rate equal to the battery's capacity) directly impacts charging time. While higher currents offer faster charging, excessively fast charging can reduce battery lifespan or cause damage, to prevent this, ensure the battery charger's output current matches the battery's recommended charging rate.
• Safety Features: Critical for preventing damage to both the battery and charger, as well as ensuring user safety. Look for features like overcharge, short-circuit or over-heating protection.
• Indicators and User Interface: Besides simple LEDs, advanced industrial battery chargers may feature LCD displays showing charge percentage, voltage, current, and error messages.
• Portability and Form Factor: Battery chargers come in various form factors, including wall-plug units, desktop chargers, multi-bay chargers for multiple batteries, and compact car chargers for on-the-go use.
• Environmental Factors: Some advanced battery rechargers incorporate temperature compensation to adjust charging parameters based on ambient temperature, optimising charging efficiency and battery life in varying conditions.
• Efficiency: Consider the charger's energy efficiency. More efficient chargers waste less power as heat, leading to lower energy consumption and cooler operation.

Industrial Applications of Battery Chargers

Battery chargers are critical components in a vast array of industrial applications, ensuring the continuous operation, reliability, and safety of equipment and systems in Singapore and beyond.

Material Handling and Warehousing

Battery chargers are the lifeblood of motive power equipment such as forklifts, electric automated guided vehicles (AGVs), automated mobile robots (AMRs), order pickers, and more. Chargers for this sector are often high power and capable of rapid charging to minimise downtime.

Manufacturing and Automation

Battery chargers are used to power AGVs and AMRs for internal logistics, backup power for critical control systems, charge power tools, and support industrial robots. Chargers for automation are often integrated into charging stations or directly onto the AGVs/AMRs for seamless operation.

Telecommunications and Data Centers

Central to the integrity of backup power systems, battery chargers are critical in maintaining charge on large battery banks for Uninterruptible Power Supplies (UPS) that provide immediate backup power to servers and networking equipment. These chargers often include advanced features like remote monitoring, precise float charging, and temperature compensation for maximum reliability.

Transportation and Logistics

Battery chargers are vital for charging electric vehicles (EVs) that range from passenger cars and buses to electric trucks, ground support equipment (GSE) at airports, electric rail systems, and marine vessels. Chargers in this sector vary widely and must be robust to withstand demanding operational environments.

Utilities and Power Generation

Battery chargers play a critical role in ensuring the stability and reliability of electrical grids and power generation facilities, providing critical DC power for switchgear control, protective relays, emergency lighting, and communication systems in substations. Large lead-acid (flooded or VRLA) battery banks are traditional for these critical backup roles.

RS SG is Your Trusted Distributor for Battery Chargers

Looking to buy battery chargers online to meet your industrial and commercial needs in Singapore? Let RS be your trusted distributor – in our shop, you will find products from brands that include Mascot, MEAN WELL and Ansmann.

If you also require jump starters, power banks, and solar chargers, we have got you covered as well. Purchase your battery rechargers, industrial battery chargers and other accessories online today. To find out more about our ordering process, delivery services and delivery fees, please refer to ourdelivery page.