A solar charge controller has to perform three primary tasks: protecting the batteries from overcharging, protecting the solar panels from reverse current when the sun goes down, and adjusting the solar voltage and current from the solar panels to the optimal battery charge voltage and current.
Solar charge controllers must be installed as close to the battery bank as possible in a well-vented dry compartment. For the charge controller to sense the state of charge (SOC) of the batteries, it needs to be connected by the shortest thickest, and most flexible wiring to make the connection.
The wire leads from the solar panels can be configured to be further away from the solar charge controller and the battery bank, but the charge controller and the battery bank must be as close as physical constraints will allow them to be.
- Close together but well vented
- Connected with upsizing copper wire connectors
- Well secured to connectors with identical metal fasteners
Let’s look at identifying the ideal location for installing the battery bank and solar charge controllers, and other parallel charge controllers.
The Best Location For The Solar Charge Controller
The best location for the solar charge controller is as close to the battery bank as possible. A dedicated power utility room or the garage near the electrical distribution panel is ideal.
We first need to identify the best location for the battery bank installation and allow space for the addition of other components such as multiple charge controllers and inverters.
Battery banks are not allowed to be installed in habitable rooms due to the production of gasses in lead-acid batteries and the risk of fire for Li-ion batteries.
Battery banks may also not be housed in ceiling crawl spaces, wall cavities, under stairs or walkways, in an escape route, or near combustible materials.
Battery Banks Locations
The best locations for battery banks are on the inside of an exterior wall of the house or garage. Ideally, a well-vented, cool, dry, and secure power utility room is needed. The ambient temperature in the battery utility room should never fall below the freezing temperature of the water.
Ideally, the batteries can be placed on wooden battery trays at floor level with at least four feet of clearance on either side of the battery bank. Above the battery bank must be sufficient space for the routing of cabling and the installation of charge controllers, inverters, and other system components.
If the battery bank is located inside the garage, install a bollard around the base of the battery bank and device panel above the battery bank to protect the installation from vehicles parked in the garage.
Design The Solar System And Utilities Room For Expansion
Underestimating the solar power system needs is a common mistake, and it is best to plan your system installation in phases allowing for expansion in subsequent phases. Plan to have space above the battery bank to install additional solar charge controllers.
The cable routing between the solar charge controllers and the battery bank must be as short as possible and allow for connecting cables of significant gauge.
As more solar arrays are added to the power generation, these must be connected to the batteries via dedicated solar charge controllers.
Also, plan to have space to install inverters from the solar panels or the battery bank to the main distribution panel. Allow for a well-thought-out layout for the cable routings and system components.
Label all cables and components clearly and identify safety protocols for the power utility wall.
Get professional advice for the design and sizing of your solar system. The potential that your future power demand will be higher than your current demand is very high. Home fast charging of your future electrical vehicles is a real possibility.
Expert solar system designers and installers are great at designing for future expansion.
The Solar Charge Controller – Close To The Battery Bank
The task of the solar charge controller is to sense the state of charge of the battery bank and regulate the charge voltage accordingly. The solar charge controller is programmed to optimally charge the battery during a state of discharge but to slow down the charge rate as the battery nears a full state of charge.
The solar charge controller also protects the solar array against a reverse current flowing back from the battery bank to the solar panels as the sunlight becomes too weak to push current into the charge controller.
The solar charge controller charges the battery bank as a stable voltage even when the sunlight intensity fluctuates by adjusting the charge current.
Wire Gauge and Cable Length
The wire gauge and cable length selected to connect the charge controller to the battery bank must be as short and thick as possible.
Short thick copper connections will eliminate voltage drop and allow a current of varying strength to flow to the battery. In very cold conditions, the solar panels will achieve optimal power production resulting in above-average power generated.
The solar charge controller has to maintain the stable charge voltage but increase the current strength to the battery bank. The connecting cabling and the Ampere-rating of the solar charge controller must be selected to cope with the extremes of the system.
Mount the solar charge controller in such a position above the battery bank connection terminals so that the positive and negative cables from the charge controller are easy to connect even when they are very thick and inflexible.
Solar Charge Controller Connections Made Easy
It is important that the wire connectors on the solar charge controller are big enough to accept the correct wire size between the battery bank terminals and the charge controller. The solar charge controller must accept 6AWG or 8AWG directly into the designated connectors and enable them to be tightly torqued.
The short thick 6AWG or 8AWG cables must the fitted with battery terminal connectors that are tightly crimped onto the wire and with heat shrunk sleeves protecting the connector junctions.
Before crimping the battery connection terminals into place, check on how to orient the battery connector to prevent it from placing strain on the battery terminal once fastened in position.