Energy Calculator

solar · battery · DC systems

Quick converters

Single-purpose calculators. Type in any field, the rest update.

System builder

Define a complete system. Sources → Battery → Loads, with conversions and wiring. Everything below updates as you type.

Battery

Pick a pre-built pack, or design one from cells.

Sources

Solar arrays, AC chargers, alternator. Energy in.

Loads

Devices drawing power. Pick from library or add custom.

Conversions

Auto-suggested where source / battery / load voltages don't match. Override efficiency if you know better.

Wiring

Per-leg cable length. AWG auto-recommended for < 3 % drop and 1.25 × ampacity headroom.

Results

Updated live as you change anything above.

Load Planner

Add up equipment consumption and get back the right battery and solar array. Compares 12 / 24 / 48 / 96 / 120 V banks, sizes panels in series-vs-parallel, projects sustainability over 14 days.

Equipment

Add devices from the library. Counts and duty-cycles let you describe a real deployment.

Targets

Runtime requirement, sun availability, depth-of-discharge, and cell type for the cell-count math.

Bank voltage comparison

Each candidate sized for the same load and runtime. Click a card to pin a voltage; otherwise the highest-efficiency winner is auto-selected.

Pack runtime scenarios

For the selected bank, here's the pack you'd need to run 12 / 24 / 48 hours on battery alone (no solar input).

Solar array

Pick the panel you have access to. The table compares all valid S × P layouts — boost-mode rows are flagged as the inefficient option.

Sustainability projection

14 days of pack state-of-charge, given the recommended solar input and the daily load draw. If you're net-negative, the bars decay — and we show how many days until empty.

Why isn't this working?

Every blocking issue with the current configuration, with a specific fix for each.

Recommended build

Final spec for the selected bank voltage and panel.