300-399W Solar Panels

Cost and fit. Lower-wattage panels cost less per panel and their smaller 60-cell/120-half-cell frames fit tight roofs, RVs, and ground mounts where 500W+ large-format modules are physically too big. They're also the right call when expanding an older array — matching electrical characteristics matters more than nameplate wattage.

Yes — this is the most popular class for off-grid cabins, RVs, and boats. A pair of 370-400W panels with an MPPT charge controller comfortably charges a 400-800Ah 12V battery bank, and the physical size is manageable for one-person installs.

You can, but match the electrical specs. Panels on the same string should have similar voltage (Vmp) and current (Imp) ratings, or the weakest module drags down the string. Send us your existing panel's model number and we'll confirm compatibility before you buy.

Single panels and small quantities ship parcel or LTL depending on size; pallet quantities (typically 30-36 panels) ship LTL freight on a single pallet with curbside delivery. Freight quotes are calculated at checkout or by our team for large orders.

Panels in this class carry manufacturer product warranties of 12-25 years and 25-year linear performance warranties guaranteeing roughly 80-85% of rated output at year 25. Exact terms vary by brand — check the datasheet on each product page.