The Most Common Causes of UPS Battery Swelling

Why do UPS batteries swell?

A swollen UPS battery is not a simple malfunction .
This is a serious security issue requiring immediate action .

Let's be clear:

A swollen UPS battery should not be used continuously.

So why does a UPS battery swell, what does this mean, and what should be done?
Let's explain it step by step 👇

What does UPS battery swelling mean?

VRLA/AGM/Gel batteries used in UPS systems are sealed type .
Under normal conditions, it never loses its shape.

If the battery is swollen:

• There is gas formation inside.

• The chemical balance has been disrupted.

• The battery is no longer healthy.

👉 This indicates that the battery has reached the end of its lifespan or
This indicates that it was operated under incorrect conditions .

The Most Common Causes of UPS Battery Swelling

1️⃣ High Ambient Temperature 🌡️ (The Biggest Reason)

Heat is the biggest enemy of UPS batteries.

• Ideal temperature: 20–25°C

• If the UPS is placed inside a cabinet, under a desk, or in an unventilated area

• If there is inadequate cooling in the server room

📉 As the temperature increases:

• The internal pressure of the battery increases.

• The gas cannot be released.

• The battery swells.

2️⃣ Overcharging (Incorrect Charging Voltage)

If the UPS charging circuit is not working properly:

• The battery is overcharged.

• The electrolyte gases.

• Internal pressure increases.

This situation generally:

• In low-quality UPS systems

• On faulty UPS circuit boards

• This is seen in aftermarket batteries.

3️⃣ The Battery Has Reached the End of Its Lifespan

Average lifespan of UPS batteries:

• ⏳ 2–3 years (VRLA / AGM)

As the battery ages:

• The chemical structure breaks down.

• Charging and discharging become unbalanced.

• The risk of swelling increases.

📌 Most swollen batteries are old batteries .

4️⃣ Operation Under Excessive Load

If the UPS is constantly operating at its limit:

• The battery switches on and off frequently.

• It keeps getting hot.

• Internal pressure increases.

📌 Small UPS + large system
= premature battery swelling

5️⃣ Poor Quality or Incompatible Battery

• Unoriginal

• Seemingly compatible but unsuitable

• Low-quality batteries

It doesn't behave properly during charging.

Conclusion:

• Gasification

• Swelling

• Early failure

What happens if a swollen UPS battery is used?

⚠️ There are serious risks:

• ❌ The battery may explode.

• ❌ Acid leak may occur

• ❌ Damages the UPS and surrounding devices.

• ❌ Poses a fire risk.

👉 That's why a swollen battery should absolutely not be used .

What to do if a UPS battery is swollen?

✅ Things to do:

1. Turn off the UPS.

2. Disconnect the power supply.

3. Remove the battery before use.

4. Replace the battery.

5. Have the UPS charging voltage and ambient conditions checked.

❌ Things you shouldn't do:

• Using the battery by straining it

• It means "It'll manage for a while longer".

• Continuing to charge a swollen battery

How to Prevent Battery Swelling?

• Use the UPS in a cool, well-ventilated area.

• Choose a UPS with the correct VA capacity.

• Replace the battery before its lifespan ends.

• Use a high-quality and compatible battery.

• Have your battery tested at least once a year.

Are the risks greater in camera and server systems?

Yes.

• CCTV and server UPS systems

• It operates under constant load.

Because:

• Battery swelling is more common.

• It leads to more serious consequences.

📌 Battery checks should not be neglected in these systems.

What do we do at cctvburada?

As cctvburada;

• 🔍 We safely replace swollen UPS batteries.

• 📊 We are performing UPS charging and load analysis.

• 🔁 We determine the correct battery type and capacity.

• 🔧 We are conducting testing and commissioning after the replacement.

We're eliminating the risk, not the swollen battery.