Lithium Battery Calculator
Free lithium battery calculator for runtime, capacity, and system sizing. Estimate battery Ah, Wh, runtime hours, and solar-compatible battery size for 12V, 24V, and 48V systems.
Lithium System Sizing Tool
Enter voltage, battery capacity, load power, daily energy use, and chemistry to estimate runtime, battery energy, and suggested solar-compatible sizing.
Runtime, Capacity and Sizing Estimator
Use this calculator for 12V, 24V, or 48V lithium systems when planning RV, solar, backup, or portable power battery setups.
Calculation Results
These results show runtime hours, battery Ah and Wh, and a simple solar-compatible battery sizing estimate.
Educational Estimates Only: Real performance depends on inverter losses, temperature, BMS limits, wiring, charging profile, and true daily load patterns. Always verify with datasheets for critical use.
What it calculates
This lithium battery calculator combines runtime, battery energy, and system sizing into one simple planning tool.
This tool calculates runtime hours, battery Ah and Wh, solar-compatible sizing, and supports 12V, 24V, and 48V systems. To use it, enter voltage, enter capacity or load, choose chemistry, and get an instant result.
Battery runtime is calculated by converting battery amp-hours and voltage into watt-hours, then dividing by load watts. This is the standard way to compare battery capacity across different voltages and estimate how long a system can run.
For solar applications, LiFePO4 is generally the best chemistry choice because it is safer than many other lithium types and is known for long cycle life. Higher-voltage systems such as 24V and 48V are also common because they can move the same power at lower current than 12V systems.
What it calculates
- Runtime hours.
- Battery Ah and Wh.
- Solar-compatible sizing.
- 12V, 24V, 48V systems.
How to use
- Enter voltage.
- Enter capacity or load.
- Choose chemistry.
- Get instant result.
How do I calculate battery runtime?
Runtime = Battery Wh ÷ Load W, after converting Ah × V to Wh. In real use, usable depth of discharge and system losses should also be considered.
Which chemistry is best for solar?
LiFePO4 is the best choice for solar due to safety and long cycle life. It is widely used in off-grid, RV, backup, and storage systems.
Frequently Asked Questions
These are common questions about lithium battery runtime, chemistry, and battery sizing for solar-compatible systems.
How do I calculate battery runtime?
Runtime = Battery Wh ÷ Load W, after converting Ah × V to Wh.
Which chemistry is best for solar?
LiFePO4 is the best choice for solar due to safety and long cycle life.
Can I use this for 12V, 24V, and 48V systems?
Yes. The calculator supports common nominal lithium system voltages including 12.8V, 25.6V, and 51.2V.
Why convert Ah to Wh?
Because watt-hours show actual energy and let you compare batteries across different voltages more accurately.
Is LiFePO4 better than standard Li-ion for solar?
For most solar storage systems, LiFePO4 is preferred because of its longer cycle life, thermal stability, and safety-focused chemistry.
How do I size a lithium battery for solar?
Estimate daily energy use in Wh, divide by usable depth of discharge, then divide by system voltage to convert the result into required amp-hours.
Does a higher voltage system change battery energy math?
The core Wh math stays the same, but higher voltage systems usually reduce current for the same power and can be more efficient in larger setups.
Can I use this for RV or backup systems too?
Yes. The same runtime and battery-sizing math works for solar, RV, camper, marine, and backup battery systems.
Is the result exact?
No. It is a planning estimate. Real runtime and sizing depend on load variation, inverter losses, temperature, and battery condition.
What input should I enter first?
Start with voltage and chemistry, then enter battery capacity, load power, or daily energy use depending on what you want to estimate.
Size Lithium Systems More Clearly
Use this calculator to estimate runtime, energy, and battery size for lithium systems, then compare related tools to refine your setup more accurately.
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