SOLAR / BATTERY / CHARGING

Solar System Sizing Calculator

Estimate a solar array, battery bank, and charge controller from your daily energy needs.

For RV and off-grid planning
1

Off-Grid Solar System Calculations

Enter load power and daily run time. The worksheet estimate below and the configuration on the right use these same inputs.

W
h / day
h / day
days
Table 1 worksheet estimate—
Battery capacity—
Solar power—

Configuration options

These affect the recommended configuration on the right, not the worksheet estimate.

W / panel
Primary load type
Inputs are not saved

Recommended configuration

Based on your current inputs

Estimate
Recommended solar array
—W
Panel combination—
Calculated minimum—
Nominal battery bank capacity
≥ — Ah
—
Total MPPT output current
≥ — A
Use one or more suitably rated controllers
Estimated daily energy to loads—

—

SELECTED BY ACOPOWER

ACOPOWER Mono Solar Panel——100W,175W,200W Solar panel Mono Solar Panel 100W · 175W · 200W View product 12V 200Ah LiFePO4 Deep Cycle Lithium Battery Battery LiFePO4 Battery 12V · 200Ah View product ACOPOWER Midas MPPT Solar Charge Controller——30A, 40A, 50A, 60A Charge controller Midas MPPT 30A · 40A · 50A · 60A View product

These product examples are not matched to your inputs. Check voltage, ratings, and availability on each product page.

CALCULATION NOTES

How it is calculated

Recommendations are rounded up. Battery Ah uses the selected calculation voltage; MPPT current uses nominal system voltage.

01 / Solar array

Required watts = daily energy use ÷ load efficiency ÷ peak sun hours ÷ 75% solar yield. Round up to whole panels.

02 / Battery bank

Nominal Wh = daily energy use ÷ load efficiency × autonomy days ÷ 80% usable capacity. Divide by the selected calculation voltage for Ah.

03 / MPPT current

Total output current ≥ actual array watts ÷ nominal system voltage × 1.25 headroom. Round up to the next 10 A increment.

AC load efficiency: 90%DC load efficiency: 100%Solar yield allows for weather, temperature, and wiring losses
Before installationThis is an energy sizing estimate. Check PV input Voc / Isc, battery charging voltage and BMS limits, series and parallel wiring, inverter peak load, cable sizing, and protection against the actual equipment. Use peak sun hours for the less favorable season at your location.

FROM THE ACOPOWER WORKSHEET

Quick worksheet calculations

Tables 2 and 3 from the ACOPOWER spreadsheet. Table 4 is the main calculator above.

2

Calculating solar panel power based on the battery

Solar power—
3

Calculate charging time based on power supply capacity

Charging current—
Charge time—