You will need to identify a suitable location for the batteries. This could be a room within a building, or a separate building for battery housing.
It is important to try to keep the entire solar system - solar array, batteries, controllers and inverters - as close together as possible in order to keep the lengths of required cable as short as possible. The length of the cable is an important consideration for efficiency.
You are looking for a location that fits the following criteria:
Water and weather proof
- Unaffected by direct sunlight
- Insulated to protect against extremes of temperature
- Allows for the ventilation of gases
- Protected from sources of ignition
- Away from children and pets
Lead acid batteries give off very small quantities of explosive gases when charging, so they must have adequate ventilation. You must ensure that wherever your batteries are stored, the area receives adequate external ventilation in order to ensure that these gases cannot build up.
Because of the extremely high potential currents involved with lead acid batteries, the batteries need to be stored in an area that is secure from children and pets. Batteries should not be installed directly onto a concrete floor. In extreme cold weather concrete can cause an additional temperature drop inside the batteries, adversely affecting their performance.
For all of these reasons, batteries are often mounted on heavy duty racking, which is then made secure using an open-mesh cage.
If you are installing your batteries in an area that can get very cold or very hot, you should insulate your batteries. Extreme temperatures do adversely affect the performance of batteries, so if your batteries are likely to be in an area where the temperature drops below 0°c (32°F) or rise above 45°c (113°F), insulation is highly advised. Polystyrene (styrofoam) sheets can be used beneath and around the sides of the batteries to keep the batteries insulated. DO NOT INSULATE THE TOP OF THE BATTERIES, as this will prevent the batteries from venting properly and may cause shorts in the batteries if the insulating material you use is conductive.
Controllers and inverters need to be mounted as close to the batteries as possible. These are often wall mounted, but can also be mounted to racking. They need to be mounted indoors. Large inverters can be extremely heavy, so if you are planning to wall mount an inverter, make sure that the wall is a load-bearing wall and is capable of handling the weight securely.
While you are on site, consider the likely routes for the cables - especially the heavy duty cables that link the solar array, controller, batteries and inverter together. Try to keep the cable lengths as short as possible, as longer cables mean lower efficiency. Measure the lengths of these cables so that you can confirm the correct specification for cables as you begin planning for your solar installation.