purchase of ups batteries for cad lab in mechanical engineering department , cat ( a ) -items to be supply and installation , ups battery: tubular battery ( buy back ) capacity: 100ah voltage:12v type: normal lead acid type battery life: minimum 4 years unconditional replacement guarantee make: any reputed brand shelf life: a fully charged battery should stand storage for minimum 6 months period of manufacturing: the battery should not be manufactured six months earlier than the date of supply distilled water requirement: distilled water addition of once in six months frequency should be sufficient to maintain the electrolyte level. , cat ( b ) - buy back items , less buy back: old tabular battery :135 ah 12v