Real RC LiPo C Rating Calculator
What this calculator does
The Real RC LiPo C Rating Calculator helps RC hobbyists move beyond the printed C rating on a battery label. A label C rating suggests how much current a pack should supply, but many packs do not deliver the same real-world performance under continuous load. Internal resistance, cell count, capacity, voltage sag, temperature, and pack age can all change the current a battery can realistically support. This calculator is useful for RC cars, EDF jets, airplanes, boats, and any setup where battery load matters. Enter the pack capacity, label C rating, and internal resistance when known. The result gives a practical current estimate and helps show whether a battery is likely to be a strong match for the setup. Example: a 5000mAh pack labeled 100C may look like a 500A battery by label math, but real voltage sag and heat may show a much lower useful current. Use this calculator with RCexplained battery testing data for a more realistic battery decision.
In practical terms: It estimates practical LiPo current capability using more than label C rating so a pack can be matched to the load more realistically.
How to use it
Enter pack capacity, advertised C rating, internal resistance if known, and setup current. Compare the result against measured RCexplained battery data when available.
Example calculation
Check whether a 5000mAh pack is suitable for a 100A setup by comparing label current, IR-based current, and expected voltage sag.
FAQ
What does LiPo C rating mean?
C rating is a current multiplier based on capacity. A 5000mAh 50C pack has a label current of 250A, but that number may not represent real continuous performance.
Why is the advertised C rating often misleading?
Advertised C ratings are often used as a marketing number and can be wildly overstated. Packs with the same label C rating can perform very differently under real RC load, especially when voltage sag, heat, and delivered capacity are measured.
How do I estimate real-world current capability?
Use capacity, internal resistance, loaded voltage behavior, delivered capacity, temperature behavior, and RCexplained performance data when available. The label C rating should be treated as a loose marketing reference, not the main sizing method.
Should I use internal resistance or label C rating?
Use internal resistance and measured performance data first. Label C rating can identify what the manufacturer claims, but it is often misleading and should not drive the final battery decision.
How does RCexplained battery testing compare to manufacturer ratings?
RCexplained focuses on loaded voltage, delivered capacity, internal resistance, current behavior, and temperature under practical RC-style testing so packs can be compared by real performance instead of label claims.