When it comes to UPS batteries, not all are made equal. The Yuasa SWL series is one of the most trusted lines of sealed lead acid (SLA) UPS batteries in the industry, but with multiple models available, how do you know which one is right for your needs?
In this blog, we’ll break down everything you need to consider before choosing a Yuasa SWL battery. That includes key specifications, compatible systems, applications, and tips to avoid common mistakes.
Whether you’re supporting a single server cabinet or an entire data centre, the right battery can make all the difference.
What Makes Yuasa SWL Batteries Different?
The SWL (Superior Wattage Longlife) series from Yuasa is a performance-enhanced version of their standard NP range. They’re designed specifically for high-rate discharge applications, which makes them ideal for UPS systems, emergency lighting, and critical power backup scenarios.
Key features include:
- Longer service life (typically 10–12 years)
- High energy density in compact form
- Excellent discharge performance
- Maintenance-free and valve-regulated design
- Manufactured to ISO quality standards
Thanks to these traits, SWL batteries are often used in environments where consistent power is crucial, such as hospitals and banks.
Step 1: Know Your UPS System’s Requirements
Before selecting a battery, you need to understand your UPS unit’s technical specifications.
That means checking the following:
- Voltage. Most small UPS systems run on 12V batteries, but larger systems may use 6V or 2V blocks in series.
- Battery layout. Look at the existing battery configuration: e.g. 2x 12V 38Ah batteries connected in series.
- Battery dimensions. SWL batteries come in different sizes, and incorrect fitment can cause airflow or cabling issues.
- Discharge rate. What runtime do you need during an outage? Higher discharge rates require batteries with stronger watt-per-cell output.
If you’re replacing existing batteries, start by identifying the exact model already in use. If not, consult your UPS manufacturer’s spec sheet or manual for guidance on compatibility.
Step 2: Match Battery Capacity to Runtime
Yuasa SWL batteries are available in a range of Amp-hour (Ah) capacities, which directly affect how long your system can stay online during a power failure. Remember, bigger isn’t always better. Batteries which are too big cost more and may not improve runtime if the UPS system is not calibrated for them.
To calculate the required Ah, consider:
- Your UPS wattage load
- Required backup time (e.g. 10 minutes or 1 hour)
- Ambient temperature, as battery capacity degrades in extreme heat or cold
Use battery runtime calculators where available, or speak to our expert team for load-specific recommendations.
Step 3: Consider Your Environment and Operations
The performance of batteries is affected by the conditions in which they’re used. When choosing a Yuasa SWL model, keep the following in mind:
Temperature
The estimated lifespan (10–12 years) is calculated assuming there is a constant temperature of 20–25°C. Higher temps accelerate chemical degradation. If your system runs hot, opt for models with better heat resistance or factor in more frequent replacements.
Charging Regime
UPS systems use float charging to keep batteries topped up. Yuasa SWL batteries are built for this, but incorrect voltages or fluctuating input can reduce efficiency. Ensure your UPS is correctly configured for SLA batteries.
Installation Space
If you’re working in tight rack units or wall cabinets, make sure to choose a model with dimensions that fit the available enclosure. Overcrowding leads to overheating and premature failure.
Step 4: Source from Reputable Sellers
The battery market is full of copycats and dodgy imports, and using non-genuine or rebranded batteries in a UPS system can be dangerous.
With UPS Battery Shop, you can be assured our batteries are genuine Yuasa models.
That means they come with a valid manufacturing date code. The supplier also offers a warranty (typically 1–2 years for Yuasa SWL).
The battery is stored and shipped correctly, as long storage without charge can degrade performance
As an authorised UK distributor, UPS Battery Shop can help you avoid these pitfalls.
Step 5: Think Long-Term: Maintenance, Monitoring and Replacements
Even sealed lead acid batteries need some attention. While Yuasa SWL units require little maintenance in terms of topping up fluid, you should still plan for:
- Routine testing (e.g. impedance or load testing every 6–12 months)
- Planning for replacements before they actually fail
- Safe disposal via certified battery recycling services
With battery monitoring systems or UPS software that logs charge/discharge events can help you spot degradation early and extend your equipment’s life.
Choosing the right Yuasa SWL UPS battery isn’t just about grabbing the highest capacity on the shelf. It’s about aligning the right technical fit with your system’s load, runtime needs, installation environment, and long-term reliability goals.
If you’re unsure which model to pick, a specialist UPS battery supplier will be able to recommend the best match based on your specific setup.
Need help selecting or ordering? Get in touch with our team today. We stock the full range of Yuasa SWL batteries and offer same-day dispatch across the UK.
