Yuasa SWL+850 Industrial VRLA battery - 12V / 28.8Ah (High Rate Performance)

The Yuasa SWL+850 is a compact high-performance monoblock from the proven SWL+ Series. With a nominal capacity of 28.8 Ah (C20), this 12-volt battery offers one of the highest energy densities technically possible in this housing format.

It is the powerful upgrade to the standard models (such as SWL750 or NPL24-12). By optimising the internal plate structure, the SWL+850 delivers significantly more energy and higher discharge currents without taking up more space in the battery cabinet. Thanks to the Eurobat "Very Long Life" classification, it is the ideal choice for UPS systems that need to run reliably for over a decade.

Highlights at a glance

• Maximum capacity (28.8 Ah): With almost 29 Ah, this block offers approx. 20% more energy than standard batteries in the 24Ah class. This enables longer autonomy times on the same footprint.
• SWL+ power upgrade (850 watts): The code number "850" stands for the increased power output (watts per block during short-term discharge). It is specially designed for modern UPS systems that have to cope with high inrush currents.
• Eurobat "Very Long Life": Classified for a service life of 12+ years (design life up to 15 years). This significantly minimises maintenance and replacement costs (TCO).
• HT Element X technology: The advanced lead-calcium-tin alloy of the grid plates reduces internal corrosion and self-discharge. This ensures maximum reliability even in years of standby operation.
• Maintenance-free AGM technology: VRLA design (valve regulated) with electrolyte bound in glass fibre. The battery is leak-proof, vibration-resistant and can be installed in any position (except permanently upside down).
• Compatible housing: Despite the increased capacity, the SWL+850 uses the standard housing size (approx. 166 x 175 x 125 mm), making it a direct "drop-in upgrade" for weaker batteries.

Areas of application

The SWL+850 is ideal for compact systems with maximum energy requirements:

• UPS systems (UPS): Ideal for rackmount systems and external battery packs (EBM).
• Telecommunication: Mobile radio stations and outdoor cabinets.
• Emergency lighting: Central battery systems (CBS) with high load.
• Starting applications: Generators (gensets), provided the cold cranking current is sufficient.
• Security technology: Intruder alarm systems and fire alarm panels.

Technology & Advantages

The SWL+850 differs technically from standard batteries:

1. Dense packing: Thinner, but more corrosion-resistant plates fit more active lead mass into the housing. This results in the high capacity of 28.8 Ah.
2. Low internal resistance: The internal structure is optimised for fast current flow (High Rate Discharge). This means the voltage remains stable even under sudden high load (mains failure).
3. Recombination: The VRLA system ensures that gases generated inside are recombined into water. No electrolyte escapes, and the battery does not dry out.

Assembly & Operating instructions

• Connection: The battery has M5 female thread. The recommended tightening torque is 2.5 Nm. Use a suitable tool to avoid damaging the thread in the soft lead.
• Charging voltage: Float charging (standby) at 2.275 V/cell (±1%) at 20°C. This corresponds to 13.65 V for the block.
• Temperature: The service life is based on 20°C. Permanently higher temperatures (e.g. 30°C) chemically reduce service life by approx. 50%.
• Storage: Thanks to low self-discharge (<3% per month) storable. Recharging should take place at the latest after 6 months.

Features

FAQs about the Yuasa SWL+850

What is the difference to the SWL750?

The SWL+850 is the more powerful successor model or the high-performance variant.

• SWL750: approx. 24-25 Ah capacity / 750 watts output.
• SWL+850: 28.8 Ah capacity / 850 watts output. The dimensions are identical. You can use the SWL+850 to give an old UPS "more life" (runtime).

Is the SWL+850 also available in a flame-retardant version?

Yes. The model SWL+850FR has a casing complying with UL94 V-0. If you install the batteries in public buildings or data centres, you should check whether the FR version is required.

Is the thread M5 or M6?

In this housing size (up to approx. 30Ah), Yuasa generally uses M5 as standard. Only from larger models (such as SWL1100 / 40Ah) does the standard change to M5 or M6, and for the very large to M8