When it comes to Uninterruptible Power Supply (UPS) systems, one of the most common questions is: “How long will the batteries last during a power outage?”
While manufacturers often provide backup runtime specifications, the reality is more complex, especially in the UAE’s challenging climate. Many myths and misconceptions can lead to unrealistic expectations and even critical system failures if not properly understood.
In this article, we’ll separate fact from fiction, helping businesses and individuals in the UAE better plan and manage their UPS battery runtime for reliable operation.
1. What is Battery Backup Runtime?
Battery backup runtime is the duration a UPS can supply power to connected loads after utility power fails. In the UAE, where power continuity is critical for data centers and essential services, understanding runtime is paramount Battery backup runtime is the duration a UPS can supply power to connected loads after utility power fails.
It depends on three main factors:
Load Size – More devices drawing power reduce runtime.
Battery Capacity – Measured in Ah (Ampere-hours) or kWh (kilowatt-hours).
UPS Efficiency – Conversion losses between battery DC and UPS output AC.
Understanding these factors is essential for realistic expectations.
2. Common Myths About UPS Battery Runtime
Myth 1: “UPS will run for its rated time regardless of load.”
Reality: Runtime is directly proportional to load.
Example: A UPS rated for 30 minutes at 50% load may last only 15 minutes at full load. Always check runtime curves in the datasheet.
Myth 2: “New batteries always provide full runtime.”
Reality: Even new batteries can provide less runtime if:
Batteries were stored for a long time before installation
Temperature is above optimal range (25°C for VRLA)
UPS is operating below recommended charging voltage
Myth 3: “UPS runtime is fixed.”
Reality: Runtime varies with:
Ambient temperature
Battery age and condition
Load type (resistive vs reactive)
UPS efficiency
Myth 4: “Adding more batteries always doubles the runtime.”
Reality: Only additional batteries connected in parallel with proper configuration increase runtime.
Incorrect connections can cause uneven discharge or system instability.
Myth 5: “UPS runtime is enough for long outages.”
Reality: Most UPS systems are designed for short-term backup (5–30 minutes)—sufficient for a graceful server shutdown or, critically in the UAE, for bridging the gap until the diesel generator starts up and stabilizes. Extended backup requires dedicated battery rooms or external systems
3. Critical Factors That Affect Actual Battery Runtime in the UAE
For the UAE, temperature and load profile are the most significant threats to achieving rated runtime
a) Load Profile
High starting currents (like servers, motors, or HVAC) can temporarily draw more than rated power, reducing runtime.
b) Battery Age
Batteries degrade over time, losing capacity.
Typical lifespan:
Lead-Acid (VRLA): 3–5 years
Lithium-Ion: 10–15 years
c) Temperature
Each 10°C rise above 25°C reduces battery life by ~50%.
Cold environments also reduce capacity temporarily.
d) UPS Efficiency
Energy conversion in the inverter results in losses of 5–10%, reducing actual runtime.
Step 1: Determine load in kW or kVA. Step 2: Check UPS datasheet for runtime curves at different loads. Step 3: Factor in battery age and temperature corrections. Step 4: Use formulas to estimate backup time:
For a simplified approximation:
Example:
Battery: 12V, 100Ah
UPS Efficiency: 90%
Load: 600W
Always check manufacturer curves — this is a rough estimation.
5. Tips to Maximize UPS Runtime in the UAE
Reduce unnecessary load on the UPS.
Maintain optimal battery temperature (20–25°C).
Regular battery testing and maintenance.
Use batteries with higher Ah rating if longer runtime is required.
Implement modular UPS systems for scalability.
Monitor UPS in real time using SNMP or BMS systems.
Why Choose ACDCIS?
Expertise: Specialized in supplying uninterruptible power supplies (UPS), batteries, measuring instruments, and data center solutions.
Quality: Offering high-quality, affordable solutions for critical data center infrastructures.
Reliability: Aspiring to be the reliable partner in your seamless critical operations.
Our Products & Services
ACDCIS provides a wide array of products and services tailored to meet the specific needs of data centers:
UPS Systems: Ensuring continuous power supply during outages.
Batteries: Offering various types of batteries for backup power.
Precision Cooling Units: Maintaining optimal temperatures for equipment.
Power Distribution Units (PDUs): Efficiently distributing electrical power.
Environmental Monitoring Systems: Monitoring critical parameters to safeguard infrastructure.
Contact Us
For inquiries or to request a quote, please contact us at:
ACDC Integrated Electrical Solutions is your trusted partner for data center solutions in the UAE, committed to ensuring the reliability and efficiency of your critical infrastructure.
a) Load Profile
