Solar Panels

It comes down to how much power you use each day and how long you're off mains. As a rough guide, a 120–200W panel keeps up with a typical fridge-and-lights touring setup, while heavier use or a bigger battery bank wants more. The best approach is to add up what your gear draws over a day and size the panel (and battery) to replace it — tell us what you're running and we'll help you work it out.

Fixed panels mount permanently to a roof or canopy and charge whenever there's sun, with no setup — ideal for caravans, campers and boats. Portable folding panels sit out on a lead and can be angled at the sun and moved into it while you park in the shade — great for tents, utes and topping up on demand. Plenty of people run both: a fixed panel for constant trickle charging and a folding one to add power when needed.

Yes — almost always. A solar controller sits between the panel and the battery and regulates the charge so the battery isn't overcharged or damaged. Only very small "maintenance" panels can safely connect direct. Some portable panels come with a controller built in; for a fixed panel you'll usually add a separate one sized to your panel's output.

MPPT controllers are more efficient — they can harvest noticeably more power from the same panel, especially in cooler weather or with larger or higher-voltage panels, so they're the better choice for most fixed and off-grid setups. PWM controllers are simpler and cheaper and are fine for small, matched 12V systems. If you're investing in a decent panel, MPPT usually pays for itself in the extra power it pulls.

Yes, and it's a tidy way to do it. Many DC-DC chargers have a built-in MPPT solar input, so your alternator and solar both feed the auxiliary battery from the one unit — charging on the move and topping up from solar while you're parked. If you've got (or are planning) a DC-DC charger with a solar input, you can connect a panel straight to it without a separate controller.

Yes. The panel itself doesn't care what battery it's charging — it's the controller or DC-DC charger that needs a lithium charge profile. Most modern MPPT controllers and DC-DC units let you select the battery type, so as long as that's set to lithium you're good to go. Tell us if you're running lithium and we'll make sure the controller suits it.

Less than the panel's rated wattage, and it varies with the season, weather and how the panel's angled — a panel only makes its full figure in strong, direct sun pointed at it. As a realistic rule of thumb you might get roughly 4–6 times the panel's wattage in watt-hours over a good summer day, and quite a bit less in winter or under cloud. That's why it pays to size a little generously and angle portable panels toward the sun.

Fixed panels bolt or bond to a roof, canopy or rack, with the cable run into the vehicle through a weatherproof gland to the controller and battery, fused close to the battery. Use correctly sized cable and MC4 connectors, and keep runs as short as practical to reduce losses. It's a manageable DIY job if you're comfortable with wiring and sealing — if not, we can point you to the right parts or you can have it fitted.