Operator`s manual
34
Installation, Operation and Maintainance of Buoy Operated Automatic Meteorological Stations
Power Supply
4.1 General
The Met Station is equipped with electronic sensors and an electronic datalogger. Hence electronics play an
important role in the data acquisition process. Proper performance of electronic equipment depends to a large
extent on a stable and reliable power supply. Failure of electronic equipment is all too often the result of power
surges, power cuts, and related spikes.
The above clearly indicates the crucial role of the power supply in the Met Station. Proper installation, use, and
maintenance of this element will considerably improve the performance of the equipment, and significantly prolong
the life span of the electronic components of the station.
The Met Station is equipped with an adequate power supply, which comprises of the following elements:
• Sealedrechargeablebattery;
• Solarpanel;
• Chargingunit;
• Grounding;
• Wiring.
A rechargeable lead acid battery supplies a 12 V direct current to the electronic datalogger. The battery itself is
charged by a photovoltaic solar panel. A regulator on the charging unit controls the power drain and recharge of the
battery. This regulator can be perceived as the ‘command and control center’ of the power system.
Power Supply
Box 7: Only Use Campbell Scientific BP24 and CH12R
Never connect the system to any power source other than the Campbell Scientific BP24 and the CH12R, as
this may cause serious and irrevocable damage to the equipment.
The following paragraphs present the user instructions for installation, use, and maintenance of all hardware
components of the power supply. The appropriate wiring of the sensors is included in respective sensor
paragraphs.
4.2 Sealed Rechargeable Battery
4.2.1 General
The datalogger and sensors are powered by a YUASA 24AH sealed rechargeable battery. It concerns a lead acid gel
battery, which uses a non-liquid electrolyte. The battery is sealed at the factory and does not leak or spill. The user
should not open the battery at any time since this may negatively affect the life span of the battery.
Battery lifetime varies between 2 and 10 years, depending on maintenance and charge. Most common failure of a
battery is due to (a) prolonged deep discharge, (b) overcharge, or (c) fast charge. Experience in East Africa has shown
that the battery should function properly for at least three years if operated according to guidelines specified in this
text. Keep in mind that the performance of the whole system relies heavily on the state of the battery.
There are inherent hazards associated with the use of a sealed lead acid battery. Under normal operation, a lead
acid battery generates a small amount of hydrogen gas. This gaseous by-product is generally insignificant because
the hydrogen dissipates naturally before building-up to an explosive level (4%). However, if a battery is shorted or
overcharged, hydrogen gas may be generated at a rate sufficient to create hazard.