Yuasa SWL+1850-6FR Industrial VRLA battery - 6V / 148Ah (High Rate Monoblock)

The Yuasa SWL+1850-6FR is a powerful 6-volt monoblock from the proven SWL-Plus series. Unlike the widespread 12V blocks, this particular 6V battery is used in large UPS systems and industrial applications where high capacities (148 Ah) and robust thermal stability are required.

The addition "FR" (Flame Retardant) guarantees maximum safety thanks to a flame-retardant housing to UL94 V-0. With a service life classification of 12+ years (Very Long Life) this battery is the backbone for critical infrastructures where there can be no compromise on availability.

Highlights at a glance

• Specific 6V performance (148 Ah): This block delivers a nominal capacity of 148 Ah. Thanks to the 6V design (3 massive cells), it offers higher cycle stability and thermal stability than comparable 12V solutions.
• SWL+ High Rate Technology: The SWL+ series is not only focused on capacity, but is optimised for performance. It offers up to 40% more discharge current than standard batteries, ideal for short, intensive discharge phases in UPS systems.
• Maximum fire protection (UL94 V-0): The housing is made of flame-retardant ABS plastic. In the event of an internal fault or external fire, the material prevents the spread of fire – a mandatory requirement for public buildings and data centres.
• Eurobat "Very Long Life": Designed for a service life of 10 to 12 years (or 12+ years classification). Thanks to the special lead-calcium-tin alloy, corrosion is minimised.
• Maintenance-free operation: Thanks to AGM technology (Absorbent Glass Mat), the electrolyte is bound in the mat. The battery does not gas in normal operation (recombination >99%) and never needs topping up with water.

Advantages of 6-volt technology

Why use 6V blocks instead of 12V blocks?

1. Thermal management: As the housing surface area is larger in relation to cell number, heat can be dissipated better during high current discharges.
2. Robustness: The thicker lead plates in 6V blocks are often more resistant to corrosion than the finer plates in compact 12V batteries.
3. Error reduction: Fewer cells per block means statistically less probability of failure per unit.

Installation and safety instructions

• Observe weight: At over 32 kg, this block is substantially heavier than typical 12V server batteries. Use lifting aids or work in pairs when equipping racks.
• Tightening torque: The M8 terminal bolts are designed for high currents. The recommended torque is usually 6 Nm. Loose connections can lead to dangerous arcing with the currents flowing here.
• Ventilation: Although VRLA batteries are regarded as "sealed", battery rooms must be ventilated according to EN 50272-2 to remove any hydrogen that may escape in the event of a fault.
• Charging voltage: In float charging mode (Float) 2.275 V/cell is required. For the 6V block this corresponds to 6.825 Volt (±1%) at 20°C.

Features

FAQs about the Yuasa SWL+1850-6FR

Can I mix this 6V battery with 12V batteries?

Never in series. You must never mix 6V and 12V blocks in a serial string, as the internal resistances and charging voltages are completely different. This would lead to immediate destruction of the batteries.

What does "SWL 1850" mean?

This is a power value of the Yuasa nomenclature. The number often stands for the wattage per block (at a 10-minute discharge). It marks the enormous high current capacity of the cell, which far exceeds what a standard battery of the same size can handle.

Why is this battery so heavy (32kg)?

Lead is heavy. As this battery has a high capacity and massive plates for a long service life (12+ years), the high weight results from this. This is a sign of quality – lighter batteries of the same size often have thinner plates and a shorter lifespan.