Baterie UPS 12V/ 7.5AH Yuasa NPW45-12-TW, 3-5 years---https://www.yuasa.co.uk/npw45-12-npw-45-12.htmlCapacity Ah (10-HR) : 6.6Capacity Ah (20-HR) : 7.5Length (mm) : 151Width (mm) : 65Height (mm) : 97.5Weight (kg) : 2.7Nominal Voltage : 12Capacity Ah : 7.5