A solar system is a five-to-twenty-year relationship. Teach the customer: panels rinsed monthly in dry season, battery terminals clean and tight, electrolyte topped with distilled water only (flooded type), controller lights meaning, and what NOT to do — no new big loads without asking, no 'helpful' rewiring. Your maintenance schedule and contact number on the power-room wall turn a one-time job into a career of referrals.