Date: Monday, January 8, 2006 From: Jeff Lord WHOI, MS #30 Subject: Batteries for Buoy Systems The following unit current draw represent the best experience / measurements we have over the last several years. Module Usage (milliamps, 1 year deployment) WND 12 BPR 4 SST 2 HRH 2 SWR 2 LWR 4 PRC 5 --- 31 Logger 5 PTT 11 Typical burn in is 90 days (this could include transit on a vessel), and safety factor of 20% is added on top of the minimum power requirement. These figures are conservative. A typical system would require xx 15 vdc, 120 ah batteries Modules = 4 batteries Logger = 1 battery PTT = 2 batteries Adding batteries for the possibility of defect in battery manufacturing, the system would be installed with this configuration. Modules = 6 batteries Logger = 2 batteries PTT = 3 batteries Per system (11) x 2 systems = 22 batteries for 1 year In this configuration, actual duration is calculated to be: Modules = 879 days (2.41 years) Logger = 1833 days (5.02 years) PTT = 1239 days (3.40 years) There is room in the well for 72 batteries. However packaging of electronics must be considered.