... 7.0 or 5.5mm6 pcs button batteries (digital watch style), battery life:10-12monthsSpecification(cm): 7(height) X 9( ... stop alarm at once ,that means the battery will be worn out,you need to replace ... then take away the top cover and replace the battery. Please pay attention to the anode and cathode.4 ... . Warning:in order to repleace battery easily later on ,please keep this usage direction ...