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Solar Battery Energy and Whole-Unit Sizing

Size nominal battery Wh and Ah from AC/DC loads, conversion losses and the actual SOC window; compare finite whole-unit series and parallel arrangements.

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Inputs that matter
AC load energy per day (Wh), Direct DC load energy per day (Wh), AC conversion efficiency (%), Additional inverter standby power (W), and 14 more
Output to expect
Load-based battery Wh and Ah, Whole battery-unit arrangement
  • Check the units and required inputs before comparing results.
  • Keep the assumptions with a copied result so you can reproduce the calculation later.
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Reference & details

How it works

Load-based battery Wh and Ah

Convert AC and direct-DC load energy into battery demand, then account for the actual SOC window and available capacity. Report nominal energy and Ah at the entered nominal bank voltage.

Battery demand = days × (AC Wh / conversion efficiency + DC Wh + additional standby W × hours); nominal Wh = demand / (SOC window × available-capacity factor); Ah = nominal Wh / nominal V.

Whole battery-unit arrangement

Compare a chosen series count of identical approved battery units and calculate the exact whole parallel-string count needed for the load case. Apply the manufacturer's finite series and parallel limits.

Energy per string = series count × unit nominal V × unit Ah; minimum parallel strings = ceiling(required nominal Wh / energy per string).

Updated: September 2026

Example Scenarios

Try this example to see the calculation, then enter actual documented values and preserve the measurement conditions. A failed or unresolved comparison is part of the record.

→ 151.851852 Ah nominal capacity

Try this example to see the calculation, then enter actual documented values and preserve the measurement conditions. A failed or unresolved comparison is part of the record.

→ 4 series × 2 parallel strings

FAQ

Convert AC and direct-DC load energy into battery demand, then account for the actual SOC window and available capacity. Report nominal energy and Ah at the entered nominal bank voltage. Compare a chosen series count of identical approved battery units and calculate the exact whole parallel-string count needed for the load case. Apply the manufacturer's finite series and parallel limits.

Use the exact equipment data, measurement point, operating conditions and units described in the selected mode. Record source documents, dates and unresolved conditions in Sources and assumptions. Built-in examples illustrate arithmetic; they are not manufacturer ratings or approved designs.

Use Save planning case for an explicit local history entry. Copy MD keeps current inputs and notes; Download CSV exports the result breakdown. Export portable copies before clearing storage and save a separate case after changing equipment, conditions or measurements.

About Solar Battery Energy and Whole-Unit Sizing

Convert AC and direct-DC load energy into battery demand, then account for the actual SOC window and available capacity. Report nominal energy and Ah at the entered nominal bank voltage. Compare a chosen series count of identical approved battery units and calculate the exact whole parallel-string count needed for the load case. Apply the manufacturer's finite series and parallel limits.