Storage

Understand usable battery kWh before Ah

Start with usable energy in kWh. Convert it to Ah only after choosing a nominal system voltage, then verify the battery BMS discharge and charging limits against the planned inverter and charger.

Use usable energy, not a label alone

A battery label is not the same as the energy you can safely plan to use. Chemistry, temperature, discharge limit, and BMS settings all affect the usable result.

Choose voltage after the load picture is clear

Higher voltage reduces current for the same power, but component availability and existing DC loads also matter. Treat voltage as an architecture choice, not a marketing preference.

Check the datasheet limits

Before buying, compare continuous discharge current, charge current, temperature limits, communication requirements, and warranty conditions in the actual manufacturer documentation.

Continue planning

Turn this decision into a power plan.

Carry the planning question into the system sizer, then verify the component specifications it makes relevant.

Build a power plan

Start here

Separate daily energy from peak power

AC loads

Plan an inverter around the loads that overlap

Editorial record

Maintained by Make Your Own Tools to turn “Size off-grid power” into a defined daily wh, battery reserve, panels, and inverter. The references below provide the technical context for this planning path. Its calculation rules and planning assumptions are documented in the methodology, and affected calculations pass regression checks before the review date advances.

Last reviewed
Evidence set
1 primary reference
Calculation coverage
2 affected rules checked
Read methodology →View change history ↗
Planning scope
Early off-grid power planning before component comparison.
Next check
Carry the resulting storage and current specification into the selected battery, BMS, charger, and installation documentation.
U.S. Department of Energy homeowner solar guidePlanning sequence, site constraints, energy use, and solar decision context.Open source ↗