Specifications

85
5.9.11 Radar reflectors
Radar reflectors are available for the DWR MkIII, DWR-G and Waverider SG buoys with a
475 mm hatchcover.
Two radar reflectors can be fitted on the hatchcover in order to gain an omnidirectional
radar reflecting system. This radar reflecting system doubles the buoys visibility on a 3 GHz
radar while on a 10 GHz radar the buoy will be ten times better visible.
The radar reflectors are made from corrosion resistant stainless steel.
Please follow the mounting instructions as delivered together with the radar reflectors and
note that we recommend 1 week for the lute which glues the radar reflectors to the hatchcover
surface to cure before the buoy can be deployed.
5.10 Power supply and consumption
The standard power supply for Datawell buoys are non-rechargeable, (= primary) batteries to
guarantee autonomous operation under all conditions. Optional a solar system can be installed
consisting of a solar panel and Boostcap capacitors for temporarily solar energy storage.
Datawell supplies two types of primary alkaline cells, magnetic and non-magnetic cells. The
DWR-MkIII buoy specifically requires non-magnetic batteries in order not to disturb the
magnetic compass.
Operational life of the buoy on a standard set of batteries depends on the number and
energy content of the batteries, on the set of buoy functions and options and, most important, if
the batteries are used in a continuous period. If the batteries are used with large intervals
than the battery life will rapidly deteriorate.
Table 5.10.1 Operational life based on Datacell batteries
WR-SG7 WR-SG9 DWR-7 DWR-9 DWR-G7 DWR-G9 DWR-G4
Standard 1.3 years 2.7 years 1.0 years 3.0 years 1.0 year 2.1 years 30 days
O N/A N/A 1.0 years 3.0 years N/A 2.1 years N/A
O/C N/A N/A 0.6 years 1.9 years N/A 1.7 years N/A
A 2.8 years 5.7 years 1.6 years 5.0 years 1.2 years 2.5 years 34 days
A/C 1.1 years 2.2 years 0.8 years 2.5 years 1.0 years 2.0 years 28 days
GSM 2.8 years 5.7 years 1.6 years 5.0 years 1.2 years 2.5 years 34 days
GSM/HF 1.1 years 2.2 years 0.8 years 2.5 years 1.0 years 2.0 years 28 days
I N/A N/A 1.5 - 2.3 years 4.5 - 6.5 years N/A N/A N/A
I/C N/A N/A 0.8 - 1 year 2.4 - 3 years N/A N/A N/A
5.10.1 Datacell primary and secondary cells
At the moment Datawell supplies 4 cell models as listed in Table 5.10.2. The voltage per cell is
about 1.6 V for fresh cells and 0.7 V for exhausted cells. Self discharge of the cells is less than
2% per year. All cells have a cylindrical shape with a diameter of 65 mm and a height of 205
mm ( including connectors). Different connectors are used for the anode in the centre and the
cathode near the edge to prevent reversed cells in a series connection. Batteries have a best
before date imprinted on it which also serves as a batch number. Type RC25GS is especially
designed for the DWR-G4.
Table 5.10.2. Overview of batteries for Datawell buoys.
Manufacturer Cell
colour
Type Technology Energy content
(Wh)
Magnetic* Primary or
Secondary
Datacell Green RC25G alkaline 250 yes Primary
Datacell Green RC25GS alkaline 250 yes Primary
Datacell Black RC20B alkaline 200 No Primary
Datacell Red RC16R alkaline 160 No Secondary
*magnetic cells should not be used in DWR-MkIII buoys