The SWL 2500 FR Battery range from Critical Power Supplies is an enhanced NPL design resulting in an improved energy to density ratio, giving up to 40% extra discharge capacity. All other attributes and operational characteristics are the same, thereby maintaining the benefit of a common mechanical and electrical design for users of both products. h2. Features And Benefits – Yuasa VRLA batteries can be used in any orientation excluding continuous use inverted. – Standard case material is flame retardant to (UL94) HBØ. – FR option case material is flame retardant to UL94:VØ (oxygen index 30). – SWL batteries are manufactured in factories that comply with ISO9001:2000. – FR option SWL’s comply with BS6290 Part 4 (1997). – SWL batteries comply with IEC 60896-21+22.Charging Methods (At 20°C)Standby use: Float charging voltage 2.275vpch2. CAUTION.Avoid short circuit.Do not charge in a sealed container.Service life and operational characteristics will be affected by temperature.AC Ripple reduces service life.WARNING!SWL (Standard) and (FR) battery types SWL1850; SWL1850-6; SWL2500, must never be installed permanently suspended by their handles; they are not designed for this purpose.