14.8 V
Nominal Pack Voltage
4S × 3.7V per cell. Full-charge reference: 16.8V for a standard 4.2V/cell LiPo.
LiPo Battery Calculator
The LiPo Battery Calculator estimates pack voltage, watt-hours, label-based continuous current, average battery current, load C-rate and practical runtime for standard lithium-polymer packs. It is built for drone, FPV, RC car, RC aircraft and other high-discharge setups where cell count, mAh and C rating all matter.
Enter your series cell count, battery capacity, continuous C rating and average load. The tool uses the standard 3.7V nominal LiPo cell model, then applies your chosen usable-capacity and efficiency assumptions so the runtime result is more realistic than simply dividing nominal energy by watts.
LiPo Battery Calculator for Voltage, Wh, C Rate and Runtime
Use the calculator for transparent pack math, then check the result against the specifications printed on your battery, ESC, motor, charger and connector system.
47.36 Wh
Nominal Pack Energy
Calculated from nominal pack voltage multiplied by amp-hours.
96 A
Label-Based Continuous Current
Capacity in Ah × entered continuous C rating.
5 min 51 sec
Estimated Runtime
Based on usable energy, efficiency and the entered average watt load.
26.28 A
Estimated Battery Current
Average battery-side current at nominal voltage after the efficiency assumption.
8.21 C
Average Load C-Rate
About 3.65× below the entered 30C label-based current level.
Result interpretation: This 4S 3200mAh 30C example stores 47.36Wh nominally. At 80% planned usable capacity and 90% efficiency, about 34.10Wh reaches the modeled load.
Current check: The estimated average current is below the entered label-based continuous current figure. Peak current, voltage sag and component limits still require separate verification.
How to Read Your LiPo Battery Calculator Results
The numbers are most useful when you understand what they represent, what they leave out, and which follow-up checks matter for an actual drone or RC power system.
Cell Count Sets Voltage
A standard LiPo cell is commonly treated as 3.7V nominal, so 2S is 7.4V, 3S is 11.1V, 4S is 14.8V and 6S is 22.2V. That nominal value is useful for energy math, but live terminal voltage changes through the discharge cycle.
Compare battery voltage rangesmAh Becomes Ah and Wh
Capacity in mAh becomes amp-hours by dividing by 1,000. Multiply Ah by nominal pack voltage to get watt-hours, a more useful energy figure when comparing different cell counts or estimating runtime from a watt load.
Convert mAh to Wh directlyC Rating Scales With Capacity
A C rating is not an amp value by itself. A 30C 1.3Ah pack gives a very different label-based current figure from a 30C 5Ah pack. The calculation is capacity in Ah multiplied by the continuous C rating printed for the battery.
Open the C rating calculatorRuntime Needs Realistic Losses
Nominal Wh divided by load watts is an ideal upper-bound calculation. The LiPo Battery Calculator also applies usable-capacity and efficiency percentages, which makes it easier to model a reserve and system losses without hiding those assumptions.
Cross-check battery runtimeLiPo Battery Calculator Formulas
Every main result can be checked by hand. Keeping the formulas visible helps you spot incorrect inputs and makes the output easier to compare with product datasheets.
Nominal pack voltage (V) = cells in series × 3.7V
For a conventional 4S LiPo, 4 × 3.7V = 14.8V nominal. A standard full-charge reference is 4.2V per cell, so a 4S pack is 16.8V when fully charged. Some high-voltage lithium-polymer products use different ratings, so do not apply the 3.7V/4.2V model to a pack whose label or charger specifies another chemistry or charge voltage.
Capacity (Ah) = capacity (mAh) ÷ 1,000
A 3,200mAh pack is 3.2Ah. This conversion matters because current and watt-hour formulas use amp-hours. If you only need conversion math, the Battery Capacity Calculator can help compare Ah, Wh and related capacity units.
Nominal energy (Wh) = nominal pack voltage × capacity (Ah)
A 4S 3,200mAh pack gives 14.8V × 3.2Ah = 47.36Wh. This matches the published 47.36Wh specification of a 14.8V 3,200mAh 4S Spektrum LiPo example. The same Wh formula is also used by aviation authorities when battery labels need a watt-hour rating.
Label-based continuous current (A) = capacity (Ah) × continuous C rating
A 3.2Ah pack rated 30C gives 96A from the label math. The LiPo Battery Calculator deliberately describes this as a label-based figure because the real sustained current you should use is still constrained by the exact pack, temperature, voltage sag, connector, wiring, ESC and manufacturer instructions. The Gens ace / Tattu LiPo guide shows the same Ah × C relationship. A burst C rating should not be entered as a continuous rating.
Delivered usable energy (Wh) = nominal Wh × usable % × efficiency %
With 80% planned usable capacity and 90% system efficiency, the 47.36Wh example gives about 34.10Wh of modeled load-side energy. This is a planning choice, not a universal recommendation for every LiPo pack. If you want to model a larger reserve, lower the usable percentage.
Runtime (hours) = delivered usable Wh ÷ average load watts
At 350W, 34.10Wh produces about 0.0974 hours, or roughly 5 minutes 51 seconds. This is only as good as the average-load input. Drones, RC cars and aircraft rarely draw constant power, so telemetry or measured average battery power is better than guessing from motor or ESC maximum ratings.
Practical LiPo Pack Planning
Voltage, capacity, C rating and runtime are connected, but they answer different questions. Use them together instead of choosing a battery from one headline number.
What C Rating Really Changes
C rating scales the pack's current figure with capacity. For example, 1.3Ah × 75C gives 97.5A, while 5Ah × 20C gives 100A. The two packs have similar label-based current figures despite very different C ratings because capacity is part of the equation.
That is why comparing C numbers alone is misleading. Start with expected current, confirm that the continuous battery rating is appropriate, then verify the connector, leads, ESC and motor limits. The Wire Gauge Calculator can help with an initial conductor voltage-drop check, but RC wiring and connectors still need application-specific manufacturer guidance.
Why Runtime Is Usually Shorter Than Ideal Math
High-discharge applications spend much of their time at changing power levels. Throttle position, propeller load, acceleration, tire grip, vehicle weight, flight style, wind and voltage sag can all change battery current. A simple Wh ÷ W result assumes one average load from start to finish.
Use telemetry when possible. If you know average watt draw from a flight log or power meter, enter that rather than the motor's maximum watt rating. The LiPo Battery Calculator will then apply the reserve and efficiency values you chose instead of pretending the full nominal Wh is always delivered to the load.
Series and Parallel Mean Different Things
Cells in series add voltage while capacity in Ah stays the same. Parallel cells add capacity while voltage stays the same. A 4S2P pack therefore has four cell groups in series and two cells in parallel within each group. Pack construction is not something to improvise with loose cells unless you have the required design and safety expertise.
For general battery-bank arithmetic, see the Series / Parallel Battery Calculator. For a finished commercial RC pack, use the S count and mAh printed on the label rather than trying to reconstruct internal cell details.
Charge Rate Is a Separate Specification
Discharge C rating does not tell you the allowed charge C rate. A battery may advertise a very high discharge rating while the standard charge rate is much lower. Use the battery label and manufacturer instructions, choose the correct LiPo balance-charge mode, and do not infer a safe charging current from the discharge C number.
If you need a charging estimate, use the Lithium Battery Charge Time Calculator only after identifying the battery's permitted charge rate and your charger's real power limit.
| Pack | Nominal Voltage | Capacity | Nominal Energy | Example Continuous C | Label-Based Current |
|---|---|---|---|---|---|
| 2S | 7.4V | 2,200mAh / 2.2Ah | 16.28Wh | 30C | 66A |
| 3S | 11.1V | 1,300mAh / 1.3Ah | 14.43Wh | 75C | 97.5A |
| 4S | 14.8V | 3,200mAh / 3.2Ah | 47.36Wh | 30C | 96A |
| 6S | 22.2V | 5,000mAh / 5Ah | 111Wh | 50C | 250A |
LiPo Safety and Accuracy Limits
LiPo packs can deliver high current and can be hazardous if damaged, overcharged, short-circuited or used outside their limits. Charge with equipment intended for the exact battery type, use the balance connection when required, inspect packs for swelling or physical damage, protect terminals from short circuits, and follow the manufacturer's storage and disposal instructions.
For air travel, watt-hours matter. The U.S. FAA says spare rechargeable lithium batteries up to 100Wh are generally allowed in carry-on baggage, 101–160Wh may require airline approval, and spare batteries must be protected from short circuits; airlines and international rules can be stricter. Check the current FAA PackSafe lithium battery guidance and your airline before traveling.
The LiPo Battery Calculator does not model internal resistance, cell imbalance, temperature, aging, voltage sag, connector heating, ESC switching losses, motor efficiency, propeller efficiency or burst current duration. Treat every result as a screening estimate and confirm final limits from the exact products in your system.
Worked LiPo Battery Calculator Examples
These examples show how the same formulas behave across common RC-style pack sizes. They are arithmetic examples, not product recommendations.
1
3S 1300mAh 75C FPV Example
Nominal voltage is 3 × 3.7 = 11.1V. Capacity is 1.3Ah, so nominal energy is 14.43Wh. The label-based continuous current calculation is 1.3 × 75 = 97.5A.
If the average load is 180W, usable capacity is 80%, and efficiency is 90%, modeled delivered energy is about 10.39Wh. Runtime is roughly 3.46 minutes. Actual flight time can differ substantially because power varies throughout a flight.
2
4S 3200mAh 30C Aircraft Example
Nominal voltage is 14.8V and capacity is 3.2Ah, giving 47.36Wh. A 30C continuous label gives 96A by the standard capacity × C formula. Spektrum publishes a real 4S 3,200mAh 30C aircraft pack with the same 14.8V and 47.36Wh ratings, which is a useful reality check on the energy math.
See the Spektrum 4S LiPo specifications for that product example.
3
6S 5000mAh 50C High-Power Example
Six standard LiPo cells in series give 22.2V nominal. A 5Ah capacity stores 111Wh nominally. The label-based current figure is 5 × 50 = 250A, but that number alone does not approve a 250A installation.
At a 900W average load, 80% usable capacity and 92% efficiency, modeled load-side energy is about 81.70Wh and runtime is around 5.45 minutes. The battery-side average current is about 44A at nominal voltage after the efficiency assumption.
LiPo Battery Calculator Frequently Asked Questions
Use these answers to avoid the most common mistakes with cell count, mAh, C rating, watt-hours, runtime and charging assumptions.
A standard 3S LiPo is commonly treated as 11.1V nominal because 3 × 3.7V = 11.1V. A standard full-charge reference is 12.6V, or 4.2V per cell. Always use the values stated for the exact pack and charger, especially for high-voltage LiPo variants.
First divide mAh by 1,000 to get Ah. Then multiply Ah by nominal pack voltage. For example, a 4S 3,200mAh pack is 3.2Ah × 14.8V = 47.36Wh. You can also use the site's Watt Hour Calculator for a direct conversion.
For the standard label calculation, multiply capacity in Ah by 50. A 2Ah 50C pack gives 100A. Treat that as a battery rating input, not a guarantee that every connector, ESC, wire or operating condition can sustain the same current. Manufacturer instructions remain the controlling reference.
No. Enter the continuous C rating when one is provided. Burst ratings are tied to manufacturer-specific time and thermal limits, so using a burst number as a continuous value can make the current check dangerously optimistic.
The model assumes one average watt load. Real flight power changes with throttle, wind, propeller load, maneuvers, battery temperature and voltage sag. Use telemetry-derived average watts when available. The Drone Battery Calculator can also provide a more application-focused cross-check.
No. Runtime is driven mainly by usable energy and average power demand. C rating describes current capability relative to capacity. A higher-C pack may have the same Wh as a lower-C pack if voltage and capacity are the same, so its ideal energy-based runtime can be similar.
Use a planning value that reflects your battery instructions, cutoff strategy and desired reserve. The calculator's 80% default is an editable example, not a universal rule. If your application needs more reserve, use a lower usable percentage and compare the runtime change.
No. The calculator estimates average battery current from load watts and voltage, but ESC and wiring selection must consider peak current, duty cycle, voltage rating, temperature, connector limits, cooling, conductor length and manufacturer guidance. Use the result only as one input to that design check.
It is the conventional nominal value used for standard LiPo pack arithmetic and is also listed by RC battery manufacturers such as Spektrum and Gens ace/Tattu. Some LiHV products use different nominal and full-charge values, so follow the exact pack label and charger profile when the battery is not a standard 4.2V-per-cell LiPo.
Rules depend on watt-hours, whether the battery is installed or spare, airline policy and jurisdiction. In the U.S., the FAA requires spare lithium-ion batteries to be carried in carry-on baggage and protected from short circuits; higher-capacity batteries can have additional approval limits. Check current rules before travel.
Plan Your LiPo Pack With Better Numbers
Run the LiPo Battery Calculator with the ratings from your actual pack, then compare the result with battery, ESC, motor, connector and charger specifications. Use the related tools to refine runtime, C-rate and capacity decisions before you power the system.
Calculate Another LiPo Pack