Should you count solar recharging in an outage plan?
Solar can help replenish a compatible battery. The available energy depends on conditions, so the planner starts with no solar contribution.
Start with the battery-only case
Calculate how long your essentials can run before any recharging. This gives you a clear fallback if weather, shading, placement, or a damaged cable prevents charging. A panel’s labeled watts do not mean it produces that power continuously all day.
Keep energy accounting honest
If you actually measure 300 Wh entering the battery during a test, that is a useful observation for those conditions. Do not multiply a panel’s rated watts by all daylight hours and present the result as guaranteed stored energy. Charging losses and power limits can change the outcome.
Compatibility comes first
Check the battery’s permitted solar-input voltage range, current limit, maximum input power, and connector requirements. Follow both manufacturers’ instructions, including temperature and placement rules. A connector that fits mechanically does not establish electrical compatibility.
Treat the result as a scenario
Record what happened in a realistic trial and repeat when conditions change. Keep a plan for a day with little usable sunlight. The current calculator intentionally excludes solar charging, so its runtime estimate is a battery-only scenario with the usage schedule and assumptions you entered.
Make it a plan for your home.
Choose your devices and edit the assumptions.
Open the backup planner