Yuasa NP12-12FR 12V 12Ah VRLA Battery, Flame Retardant UL94:V0 Case

Overview

VRLA means valve regulated lead acid. It is the type many people call a sealed lead acid (SLA) battery, because you never top it up with water.

This Yuasa battery has a flame retardant case, rated UL94:V0, for sites where the case material matters.

How it works

• Glass mat: the electrolyte is held in a mat rather than sloshing about as free liquid. That is why orientation is so flexible.
• Lead calcium grids: lead calcium is widely used because it limits water loss and self discharge.
• Valves: each cell has a low pressure release valve. Gas can escape and the valve then reseals.
• Float and cyclic: float means the charger holds the battery topped up on standby. Cyclic means the battery is regularly discharged and fully recharged, which needs a different voltage.

Where to use it

Batteries of this type are often used as standby back-up in equipment such as a small UPS.

Follow the battery size and type the equipment's maker asks for.

Keep it out of sealed enclosures. The gas it can release needs somewhere to go.

What the figures mean in practice

• 20-hr and 10-hr rates: Ah is charge stored. The 12 Ah figure is measured over 20 hours and the 11.1 Ah figure over 10, because a faster discharge gets less out of a battery.
• Correction factors: the -3 and -4 figures adjust the charge voltage when the temperature is not the standard 20°C. Chargers without this feature rely on a reasonably steady temperature.
• 3 A charge limit: this applies to cyclic or boost charging. On float charge there is no limit.
• 16 mΩ impedance: a lower value means the voltage sags less under load. It is a handy comparison when testing an old battery against a new one.

Installing it

• Terminals: match your leads to the FASTON 6.35 terminals before you start, and keep polarity right.
• Lifting: do not suspend the battery by any handles where they are fitted.
• Short circuits: tape or cover a loose lead while you work, since a battery can deliver a very high current through a dropped tool.

Planning your system

Work out the standby load of the system first, then check that this capacity covers the time your standard requires. Add margin for ageing, because capacity falls over the years.

You will also need a suitable charger or a charging circuit that matches the voltages above. A battery tester helps to spot a tired battery at each service visit.

Old batteries must go for recycling under local and national laws and regulations.

Standards and ratings explained

• EUROBAT Standard Commercial: an industry class that describes the expected life band, here 3 to 5 years. Treat it as a planning guide rather than a promise.
• UL94:V0: a flammability class for plastics. Material at V0 stops burning quickly once a test flame is removed, but the class says nothing about the battery as a whole.
• ISO9001: this covers the maker's quality management, not the performance of a single battery.