Specifications

86
The rechargeable cell requires a recharger. Please check the manual of the recharger for optimal
use of the rechargeable cells. In short: keep the cells fully charged as much as possible.
5.10.2 Battery status
With help of Table 5.10.3 the battery status bits may be translated into weeks left before the
buoy runs out of energy. There are two methods to determine the remaining operational life.
One is to measure the voltage and to relate this to the battery discharge curve. However, on a
nearly horizontal part of the discharge curve this is not very accurate.
The second method in fact integrates the discharge curve yielding energy delivery or
consumption versus time. This method is applied in the power consumption meter of the DWR-
MkIII, DWR-G and WR-SG buoys.
In case the buoy is equipped with the solar system this operating lifetime can be regarded
as absolute minimum. Note that the operational life t
ol
is also given directly in word 6 of the
system file, see Table 5.7.4.
Table 5.10.3. Translation of battery status in the system file to remaining operational time.
Lifetime prediction is based on primary cell use only In case the buoy is equipped with the
solar system this life time can be regarded as absolute minimum.
Battery
status
Remaining operational
life (weeks)
0 0 – 6
1 7 – 15
2 16 – 22
3 23 – 27
4 28 – 41
5 42 – 49
6 50 – 60
7 61 - or more
5.10.3 Hybrid power option
On the DWR-MkIII and WR-SG buoys, a solar system can be installed. Together with the
primary cells this makes the hybrid power system. The purpose of the hybrid power option is to
reduce primary battery drainage.
The solar system consists of a solar panel on the hatchcover and a set of Boostcap
capacitors in the hull for temporarily solar energy storage. This concept combines the reliability
of primary cells with the availability of solar energy.
The life time expectancies as presented in this manual and in the messages of the buoy are
always without solar energy contribution, and thus can be regarded as minimum life
expectancies. When installed, the lifetime expectancy of a hybrid buoy presented in the
W@ves21 software can fluctuate. This depends on the total amount of sunlight
5.10.3.1 Solar panel
The solar panel array converts the captured sunlight into electrical energy. Due to the low power
consumption of the Waverider only a small solar panel is required. The array comprises a flat
circle of 5 x 5 cm2 solar cells on top of the stainless steel hatch-cover and is protected by a layer
of polycarbonate. This rugged construction, fully integrated within the original spherical design
of the hull, makes the panel extremely robust. Using only 16 of these small cells, the array
generates a peak power of 15 times the continuous power consumption of a Directional
Waverider (specified at air mass 0).