To charge it from 10 to 90 percent, it would take just over 2 hours and 47 minutes at a constant power output. Estimate how long it takes your solar panel to charge a battery based on panel wattage, battery capacity, voltage, and charge efficiency. Formula: Charging Time (h) ≈ (Battery Ah × V × (Target SOC / 100)) ÷ (Panel W × (Eff% / 100)). Adjust for sunlight hours to find daily charging duration. Optional: If left blank, we'll use a default value of --- 50% DoD for lead acid batteries and 100% DoD for lithium batteries. Note: The estimated charge time of your battery will be. Example: A battery storage system with a storage capacity of 6.