Battery & Backup Planning
Calculate battery backup runtime, size a battery bank for power outages, convert Ah to Wh, or estimate charge times with transparent, editable assumptions.
Estimate how long your battery can power a load, with editable reserve, battery health and efficiency assumptions.
Estimate the battery capacity needed for a load and backup time, with clear planning assumptions.
Estimate how long a UPS can support your equipment from usable battery energy and load watts.
Calculate UPS battery Wh and Ah from load, backup time and editable planning assumptions.
Convert Ah, mAh, Wh and kWh using voltage, then estimate usable battery energy.
Estimate charging time from capacity, state of charge and charger output with editable battery-limit assumptions.
Estimate portable power station runtime or required capacity while checking continuous and startup output limits.
Calculate DC and AC wire gauge sizing, voltage drop percentage, and power loss in watts under NEC standards.
Calculate continuous and surge inverter wattage, DC battery amperage, fuse rating, and battery cable gauge.
Multi-source charging, chemical storage management, and pure sine wave inverted backup delivery.
Interactive Planning Journey
Follow our 4-step engineering workflow to calculate, size, convert, and verify battery performance for backup outages and off-grid living:
Calculate required nominal kWh and Ah for your connected load and target autonomy.
Convert between Amp-hours, Watt-hours, and system voltages (12V, 24V, 48V).
Simulate exact backup duration (hours/minutes) with inverter efficiency and SOH derating.
Estimate charging hours from AC chargers or solar power with CC/CV taper allowances.
Calculations, electrical losses, and design safety margins adhere to recognized engineering guidelines:
Requirements for battery storage disconnects, circuit sizing, and ventilation in residential installations.
Safety requirements for industrial and residential lithium energy storage systems and BMS controls.
Grid-tie inverter synchronization, anti-islanding protection, and voltage/frequency ride-through.
Use the Battery Runtime Calculator to estimate how many hours or days it can power your devices. For office equipment or servers, use the UPS Runtime Calculator, or check portable units with the Portable Power Station Calculator.
Use the Battery Size Calculator to find the required kWh or Ah for your backup duration, the UPS Battery Size Calculator for desktop setups, or the Home Battery Size Calculator for household outages.
Use the Battery Capacity Calculator to convert Ah, mAh, Wh, and kWh, or the Battery Charging Time Calculator to estimate recharge hours.
Use the Voltage Drop Calculator to determine copper wire gauge (AWG/mm²) and ensure DC/AC branch circuit voltage drop remains under 3%.
Use the Inverter Size Calculator to calculate continuous running watts, peak inductive motor starting surges, and DC battery cable fuse ampacity.
Explore our peer-reviewed technical reference guides, open empirical datasets, and research preprints for battery storage and electrical conductor sizing:
Real battery performance depends on depth of discharge, battery chemistry, inverter efficiency, and ambient temperature. Our calculators expose every assumption so you can adjust them to your exact equipment.
Read the calculation methodology, cross-reference engineering standards, embed tools via developer widgets, or review laboratory sources.