Unik Techno • November 24, 2023

The Crucial Connection Between Demineralised Water for Battery Efficiency

New ParagraphAt UNIK, we are often asked about the role of demineralised water in battery maintenance. This blog aims to serve as a guide for replenishing your battery’s water levels. Regularly replenishing your batteries with demineralised water is a crucial maintenance routine to ensure safety and maximise performance. 

 

What is Demineralized Water, and How is it Different from Regular Water? 

Demineralised water is clear of most mineral and salt ions. This is often achieved through ion exchange, reverse osmosis, or electrodialysis. 

 

Regular water, in contrast, contains a heavy load of impurities and dissolved minerals such as sodium, magnesium, and calcium which are detrimental to the health of batteries.  

 

Where is Demineralized Water Used in Batteries? 

Every lead acid battery, irrespective of its type, is immersed in an electrolyte solution comprising demineralised water and sulphuric acid. The amount of electrolyte is to be calculated and filled for optimum performance. 

 

While the battery is being operated, the demineralised water undergoes a chemical reaction and is broken down into hydrogen and oxygen. 

 

Why Does Demineralized Water in Batteries need to be Regularly Topped up? 

 

Over time and with consumption, the water level in the battery drops and no longer covers the electrode plates, reducing the battery’s conduction capacity. Therefore, regular top-ups with demineralised water are essential to ensure the longevity and effectiveness of the battery. While tap water or RO-purified water may seem like a viable alternative, they are not recommended for optimum battery performance and maintenance due to its impurities and minerals. 

 

With time, the dissolved minerals in non-demineralized water could clog the battery's electrodes by forming a layer of sediment. This eventually inhibits the battery from generating current. 

 

When Should You Top up the Demineralized Water in your Batteries? 

 

Overwatering and underwatering your battery can be equally harmful to your battery’s performance. 

Ideally, a battery should be topped up with demineralised water after charging. However, ensuring that the electrode plates are covered with adequate fluid before charging is also important. 

The frequency of demineralised water top-ups depends on the amount of usage. For instance, a sparingly used golf cart may need water top-ups monthly, while a forklift may need a weekly top-up. An inverter battery used as a back-up power source in urban areas could be topped up quarterly. 

 

Old batteries and hot weather warrant more frequent demineralised water level top-ups. 

 

Precautions to Follow while Topping up Demineralized Water in Your Batteries 

  • Before undertaking any maintenance work yourself, always check the warning labels to confirm if your battery can be opened for servicing. 
  • Although topping up demineralised water for batteries is a relatively safe maintenance procedure, always wear protective gear to prevent any accidents and injuries. 
  • Never add sulphuric acid to your batteries during top-ups. Batteries only consume water during normal usage; hence, sulphuric acid can compromise the safety of batteries and imbalances different cell specific gravities.  
  • Avoid overwatering your batteries as the electrolyte levels expand during the operations and cause the battery level to overflow, which damages the cell 

 

Incorporating demineralised water for battery maintenance, along with regular servicing and checkups, can significantly enhance the performance and longevity of your battery. 

 

Need more information on topping up demineralised water in batteries? 

Contact us for more details on maintenance procedures for UNIK batteries. 


By Unik Techno August 1, 2025
Sulfation is a widespread yet often overlooked issue in the world of lead-acid batteries. Frequently dubbed the “ silent killer” , it operates without obvious warning signs, quietly reducing both battery performance and service life. Whether used in industrial machinery, UPS systems, or off-grid energy storage, sulfation poses a serious risk to any application reliant on reliable battery power. What is Sulfation in Lead Acid Batteries? At its core, sulfation refers to the accumulation of lead sulphate crystals on the battery’s internal plates. This occurs naturally during discharge as the active material on the plates reacts with sulphuric acid. In a properly maintained battery, these crystals dissolve again during the charging process. However, when a battery is left undercharged, stored in a discharged state, or routinely subjected to deep discharge cycles, these sulphate crystals begin to harden. Over time, they become dense and irreversible, severely inhibiting the battery’s ability to hold and deliver electrical charge. What Causes Sulfation in Lead Acid Batteries? Understanding the root causes of battery sulfation is the first step to avoiding it. One of the most common contributors is infrequent or incomplete charging. A battery that is not brought back to a full state of charge after use may retain a residue of sulphate on the plates. This residue becomes the starting point for permanent sulfation, especially if the battery is neglected over repeated cycles. It is not just charging habits either—environmental conditions also play a significant role. High ambient temperatures accelerate the electrochemical reactions inside a battery, increasing the likelihood of crystal formation and growth. In warmer climates, or in confined battery enclosures without proper ventilation, this risk is amplified. Prevention of Sulfation in Lead Acid Batteries Prevention begins with proper charging practices. Always use a smart charger that can automatically adjust the charging voltage and current based on the battery’s state-of-charge. These chargers typically include bulk, absorption, and float stages that ensure a complete and balanced charge. Some models even include pulse or maintenance modes that help dissolve early-stage sulphate deposits, reducing the onset of crystallisation. Routine maintenance is another critical factor. For flooded lead-acid batteries, it’s important to regularly check electrolyte levels and top up with demineralised water when necessary. Low electrolyte levels expose the upper portions of the battery plates to air, causing oxidation and increasing the likelihood of sulphate build-up. In addition to fluid checks, make sure to clean terminal posts, check for corrosion, and tighten connections to ensure efficient current flow. Equalisation charging is a powerful tool in the prevention arsenal. This is a controlled overcharge applied periodically—usually once every 30 to 90 days that helps equalise the voltage between cells and reverses mild sulfation. Equalisation charges are particularly effective in larger battery banks where cell imbalance is common. However, they should only be performed according to the manufacturer’s guidelines, as excessive overcharging can damage the battery. Storage practices also matter. If a battery is left unused for extended periods, it must be stored fully charged and kept in a cool, dry environment. Batteries in storage should be recharged every 60 to 90 days to prevent the slow self-discharge that can lead to sulphate crystallisation. Even sealed lead-acid batteries are vulnerable if stored improperly. While some specialised de-sulfation chargers claim to reverse sulfation through high-frequency pulse technology, their effectiveness is generally limited to early-stage sulphate deposits. Once the crystals become hard and dense, recovery is unlikely, and battery capacity is permanently reduced. Prevention remains far more effective than any attempted cure. The consequences of ignoring sulfation can be expensive. Reduced runtime, increased charging times, and eventual failure can disrupt operations and require premature battery replacement. For businesses, this translates to higher operational costs, increased downtime, and reduced energy efficiency. At UNIK Batteries, we believe that prevention is the smartest investment. By manufacturing high-quality lead-acid batteries and state-of-the-art charging components, we help customers protect their power infrastructure from day one. Whether you operate forklifts , golf carts , maintain a solar backup system , or manage a unit of UPS batteries , we have the right solution to keep you powered and protected from sulfation. Contact us to explore our range of batteries and charging components today!
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