Types of Battery Floating Charges
The principle of floating battery charging is to maintain the full state of charge in the battery while minimizing corrosion of the negative plates. This is accomplished by controlling the charging current and voltage. The types of battery floating chargers are;
- Passive resistor-based chargers: These chargers use resistors to limit the charging current to each cell of the battery. They are simple and reliable but have some drawbacks, such as heat production and less efficiency due to energy loss in the resistors.
- Active Controllers: They dynamically adjust the charging current based on battery parameters using sensors and control circuitry. They provide optimal charging, improve battery life, and require more complex systems with sensors and control algorithms.
- Multipoint Terminal Chargers: These chargers have multiple charging terminals to ensure even voltage distribution across battery cells. They are suitable for large batteries and reduce the risk of overcharging by providing a more uniform charging profile.
- Smart Chargers: These chargers use advanced technologies such as artificial intelligence and machine learning to optimize charging based on battery usage patterns and operating conditions. They provide efficient and customized charging but require more sophisticated systems with intelligence and learning capabilities.
- Solar-powered chargers: These chargers use solar panel energy to charge batteries. They are environmentally friendly, reduce electricity costs, and require adequate sunlight for operation.
Functions and features of battery floating charge
Battery float charging uses a low-maintenance trickle charging method to keep batteries fully charged and avoid damage from overcharging. When a battery is constantly charged, the electrolyte is kept uniform and prevents the battery from stratifying. It also helps minimize sulphation, a major lead-acid battery issue.
Working principle: In a floated charging system, the battery charger primarily supplies the float or maintenance charge to the battery. If the battery gets too low, the charger will automatically switch to equalization mode to restore the battery's chemical balance. In some floated charging systems, there is a high-frequency charging stage that can be kept continuously and converted to direct current by a three-phase charger.
Functions:
- Maintain optimal capacity: Battery float chargers help maintain a battery's optimal capacity for longer by keeping the electrolyte in the lead-acid battery moving. This serves to prevent stratification and in the case of flooded batteries, discourages sulfation.
- Prevents self-discharge: Battery self-discharge occurs naturally within batteries as a normal chemical action that leads to the depletion of stored energy. Float charging counteracts this phenomenon by continually charging the battery to help reduce maintenance costs for those that require periodic electrolyte checking.
- Minimizes overcharging: Float chargers automatically control the charging current and battery voltage to prevent overcharging, which can shorten a battery's life in highly volatile situations during high-temperature environments.
- Enables equalization charging: Battery float charging enables the equalization charging process where all the battery's cells are charged equally, enhancing their longevity. This happens in lead-acid batteries where cell density needs to be avoided or minimized.
Features of floating charge:
- Automatic current and voltage regulation: This is important for prolonging battery life and preventing overcharging, which damages a battery.
- Low charging current: This ensures that battery cells are not overcharged and keeps float charging efficient.
- Simple design: Float battery chargers have a straightforward design and are efficient and economical.
- LED indicators: These visual indicators help understanding a battery's charging status and aids in troubleshooting if a problem arises.
- Microcontroller technology: It improves the battery charging process by making it more efficient and adding multiple safety features.
Applications of battery floating charge
Any application depends heavily on battery floating charging to ensure the best performance from the batteries. These include;
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Off-grid and grid energy storage systems
Batters play a crucial role in storing energy and managing power. They float charge to ensure optimum battery health and longevity. This prevents any battery deterioration or damage from the daily cycling of charging and discharging. Maintaining battery health is essential in off-grid and energy storage systems because they are responsible for supplying power when there is none.
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Uninterruptable power supply (UPS)
The UPS system helps provide emergency power when there is no electricity. It helps maintain floating battery charge to ensure battery readiness and prevent any damage from prolonged idling non-used.
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Telecom and networking
In avionic systems where floating battery voltage chargers are used, large batteries are used to avoid lengthy charging times and provide backup power. A floating charge is maintained to ensure battery readiness in case primary power fails.
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Marine and security applications
Boats, yachts, and water vehicles use floating battery charger cores to keep their batteries charged when not in use. These chargers prevent battery deterioration from idling or nonuser states. They are also used in security applications like CCTV cameras and fencing lights. Such applications use portable batteries to ensure security in remote areas. The batteries use floating charges to ensure they are fully charged and ready to power the system when needed.
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Emergency and smart grid backup
The smart grid charger floating battery is essential in maintaining the charge of backup batteries during an emergency. These batteries are fundamental during a power outage or failure. They can supply power to emergency response systems, hospitals, and critical infrastructure.
How to choose battery floating charges
Though a floating charger for batteries is useful for many applications, from the above, it is important to know how to choose one that will suit specific needs.
- Max charging current: This is the highest current the charger can use to charge the battery. This value must be calculated carefully. Since a floating charger gives a very small charging current, calculating the maximum charging current by dividing the battery capacity in Ah by ten works well. For example, a 100Ah battery will have 10A as its maximum recommended charging current. However, since we calculated this value under ideal conditions, we must consider the temperature effects and internal resistance. Due to these two factors, the maximum charging current must be adjusted downward by 20%. Using the previous example, the adjusted value will be 10A – (20% of 10A) = 8A. Hence, the charger should not exceed a maximum current of 8A.
- Minimum current: The battery will require a minimum current to keep it fully charged and prevent sulfation from occurring. The minimum current can be calculated in the same way as the maximum current, but the adjustment for temperature and resistance is not done in this case. Using the above example of the 100Ah battery, the minimum current would be 10A generally, but it could be more for different battery types. It is also important to note that for a floating charge to work, the minimum current must be less than the battery's self-discharge rate.
- Charging time: The time it takes to charge a battery is calculated using the formula: T = C / I; where T = time in hours, C = capacity of the battery in Ah, and I = charging current in A. Using the previous example, if the battery capacity is 100Ah and the charging current is 10A, then the time taken to charge the battery would be 10 hours.
Q&A
Q: What does floating charge mean?
A: This refers to a scenario in which the charging voltage is equal to the battery's open circuit voltage. Typically, batteries will release power in the form of DC power while simultaneously holding a charge by the power plant. The charging system in turn should provide the battery with sufficient power to perform its function.
Q: Can batteries be charged in floating mode?
A: Yes, batteries can be charged in floating mode. This is a common practice for lead-acid batteries, especially in applications like uninterruptible power supplies (UPS) and standby power systems. When floating charged, the battery maintains a full charge level by supplying a low-maintenance charge to avoid sulfation while it's connected to a consistent charging source.
Q: What does floating mean in battery?
A: Floating batteries means having the batteries on standby, where they can charge and discharge as needed. Float batteries are used to provide emergency power in case the main supply fails. They are kept fully charged while the system's power bus supplies the needed power for normal operation.
Q: What is a floating charger?
A: A floating battery charger is a type of battery maintainer designed to keep a rechargeable battery at its full charge state without overcharging it.
