SIZING OF M-SOLAR INSTALLATIONS
It is recommended that the battery be sized to limit the daily depth of discharge to
20% of the 100-hour rate capacity. This caters for up to 5 days of cloudy weather
whilst giving optimum life expectancy.
The daily consumption can be calculated by taking each electrical item’s wattage
and estimating the maximum time in hours that it is likely to run each day. The
product of these two figures will give the Watt-hour consumption each day. Totaling
the result for each item will give the system consumption per day. Alternatively many
web sites give the expected consumption for household appliances.
The total daily Watt-hour consumption divided by the overall nominal battery voltage
will give the Ampere-hours required each day. Multiplying this by 5 will indicate the
size of battery required.
The solar array must be able to deliver sufficient power to supply the load and
recharge the battery on an average day of irradiation plus have reasonable excess to
cater for the recharge over a few days when the battery is more deeply discharged
due to consecutive days of poor weather.
PREPARING THE BATTERY FOR SERVICE
UNPACKING
Clean off any packing material from the cells and trays. Examine carefully to see if
there has been any damage in transit.
Check that all components have been supplied.
Cells may be supplied loose or pre-assembled in 4 volt (2 cell) or 6 volt (3cell)
trays. If in trays, inter-tray cables and two take-off cables will be supplied. If
loose cells, inter-cell cables and two take-off cables are supplied.
One electrolyte level indicator per cell.
One Installation and Maintenance Manual (this document).
One battery log book.
One hydrometer.
Important: Any damage or shortages must be reported to the carrier and First
National Battery must be notified.
PREPARING THE CELLS
•
Open all vent filler plugs and examine the electrolyte levels in all cells.
•
Check all specific gravities (25°C).
•
Batteries can be put into service immediately, provided the specific gravities are
above 1.240 (25°C) and electrolyte levels are correct.
If the specific gravities are below 1.240 it is necessary to give the battery an
equalizing charge. This consists of charging at a constant current of 2.5% to 5% of
