What you need before you start
A complete solar kit generally includes four parts: one or more panels (with MC4 cables already crimped on), an MPPT or PWM charge controller (or a micro-inverter for a grid-tied balcony kit), a storage battery if the kit is stand-alone, and a fuse or breaker between the controller and the battery.
How to install a solar kit, step by step
The connection order matters as much as the connections themselves: a controller that receives current from the panel before it's wired to a battery can be damaged, having no voltage reference to regulate the charge.
- 1. Mount the solar panel. On a van roof, a pergola or a portable stand, ideally facing due south with a tilt close to your latitude for year-round fixed use, or simply laid flat for a portable kit.
- 2. Connect the controller to the battery first. Wire the controller's + and - terminals to the battery through the protection fuse, with the panel still disconnected. The controller powers up and detects the battery.
- 3. Then connect the panel to the controller. Click the panel's MC4 connectors into the controller's solar input: the charging light should come on if there's enough sunlight.
- 4. Check the charging voltage and current. Most modern controllers display these figures on a screen or via a Bluetooth app, to compare against the panel's specifications and confirm everything's working normally.
- 5. Secure and protect the wiring. Fix the cables away from friction and prolonged UV exposure, and check the seal on any cable run through a wall or roof.
Balcony plug-and-play kit or portable kit: what changes at install
A balcony solar kit (often called 'plug-and-play') connects directly to the home's mains supply through a micro-inverter and a standard socket, with no battery step: the energy produced is used directly or fed back, with no storage stage to manage. Installation is limited to mounting the panel, wiring the micro-inverter, and plugging it in.
A portable kit (van, camper, off-grid camping) runs as a closed circuit with a battery: it's the controller-then-panel sequence detailed above that applies, plus the choice of the right controller (MPPT outperforms PWM, especially above 100W of panel capacity) based on the battery's voltage.
The connections you should never reverse
On screw terminals (battery, some entry-level controllers), always double-check polarity before tightening: unlike MC4 connectors, nothing physically prevents a reversal there. A correctly sized protection fuse between the controller and the battery limits the damage from a mistake, but doesn't replace care at connection time.
How do you check a solar installation is working correctly?
A multimeter across the battery terminals should read a charging voltage slightly above its resting voltage while the panel is producing (roughly 14 to 14.4V for a 12V lead-acid battery on charge, a bit more for lithium depending on the charge profile). The controller's screen or app, where available, shows the panel's real-time output directly, to compare against its rated power adjusted for current sunlight.
Noticeably lower output than expected in full sun usually points to an orientation issue, a loosely seated connector, or partial shading on the panel, often a bigger hit than expected on panels without bypass diodes.
