The Water Battery is an old smooth bore battery locate on the foreshore below Fort Charlette. This appears to have had four guns on traversing carriages. The Battery is shown on plans for the nearby Fort Charlotte dating back to the Napoleonic Wars. It is believed to have been armed with four 32-pdr SB guns. Accroding to the plans (TNA MPHH 1.541) there was a small wooden building to the rear of the battery for storage of equipment. There is no record of any magazine for the battery.