Battery Bank Basics for Backup Power
Learn battery capacity, volts, amp-hours, watt-hours, usable energy, inverter limits and basic safety.
Capacity units
Amp-hours only become meaningful for energy when voltage is known. Watt-hours provide a more direct measure for comparing stored energy across voltages.
Usable capacity
The full nameplate capacity may not be available or desirable to use. Battery chemistry, battery-management settings and longevity targets affect usable energy.
Series and parallel connections
Series connections raise voltage; parallel connections raise capacity at the same nominal voltage. Mixing batteries or wiring large banks requires careful design.
Inverter sizing
The inverter must meet continuous load and short surge requirements while staying within the battery system’s discharge limits.
Protection
Large battery banks can deliver dangerous fault currents. Proper fusing, disconnects, cable sizing, enclosures and installation practices are essential.