This **18650 battery pack calculator** is used to determine the **optimal configuration** of **18650 lithium-ion cells** for a specific power requirement.

With a

12V battery packwith10Ah capacity, the calculator would determine how many18650 cellsto connect in series for voltage and in parallel for capacity.

## 18650 Battery Pack Calculator

Desired Voltage | Desired Capacity | Cell Capacity | Series Cells | Parallel Strings | Total Cells | Configuration | Actual Voltage | Actual Capacity | Total Power |
---|---|---|---|---|---|---|---|---|---|

12V | 10Ah | 3000mAh | 4 | 4 | 16 | 4S4P | 14.8V | 12Ah | 177.6Wh |

12V | 20Ah | 2500mAh | 4 | 8 | 32 | 4S8P | 14.8V | 20Ah | 296Wh |

24V | 15Ah | 3500mAh | 7 | 5 | 35 | 7S5P | 25.9V | 17.5Ah | 453.25Wh |

24V | 30Ah | 3000mAh | 7 | 10 | 70 | 7S10P | 25.9V | 30Ah | 777Wh |

36V | 8Ah | 2500mAh | 10 | 4 | 40 | 10S4P | 37V | 10Ah | 370Wh |

36V | 12Ah | 3000mAh | 10 | 5 | 50 | 10S5P | 37V | 15Ah | 555Wh |

48V | 20Ah | 3000mAh | 13 | 7 | 91 | 13S7P | 48.1V | 21Ah | *1010.1Wh |

48V | 40Ah | 3500mAh | 13 | 12 | 156 | 13S12P | 48.1V | 42Ah | 2016Wh |

72V | 5Ah | 2000mAh | 20 | 3 | 60 | 20S3P | 74V | 6Ah | 444Wh |

72V | 10Ah | 2500mAh | 20 | 5 | 100 | 20S5P | 74V | 10Ah | 740Wh |

60V | 15Ah | 3000mAh | 16 | 5 | 80 | 16S5P | 60.8V | 15Ah | 912Wh |

36V | 18Ah | 3500mAh | 10 | 6 | 60 | 10S6P | 37V | 21Ah | 777Wh |

## 18650 Battery Pack Formula

**Voltage calculation**:

**Total Voltage = Number of cells in series × Nominal cell voltage**

**Capacity calculation**:

**Total Capacity = Number of parallel strings × Individual cell capacity**

**Power calculation**:

**Total Power (Wh) = Total Voltage × Total Capacity**

Voltage: 18650 cells typically have anominal voltageof3.7V. To increase voltage, connect cells in series.Capacity: A single 18650 cell usually has2000-3500mAh capacity. To increase capacity, connect cells in parallel.Power: Measured inwatt-hours (Wh), it’s the product of voltage and capacity.

## How do you calculate 18650 battery pack?

To calculate an **18650 battery pack configuration**:

**Determine required voltage**: Divide target voltage by cell voltage (**3.7V**) to get cells in series.**Calculate capacity needs**: Divide desired capacity by single cell capacity for parallel strings.**Compute total cells**: Multiply cells in series by parallel strings.

For a **24V, 10Ah pack** using **3000mAh cells**:

Cells in series: 24V ÷ 3.7V ≈ 6.49 (round up to 7)

Parallel strings: 10Ah ÷ 3Ah ≈ 3.33 (round up to 4)

Total cells: 7 × 4 = 28 cells

Final configuration: **7S4P (7 series, 4 parallel)**

## How many 18650 batteries to make 1 kWh?

To calculate cells for **1 kWh (1000Wh)**:

- Choose a voltage (e.g.,
**48V**) - Calculate capacity: 1000Wh ÷ 48V ≈ 20.83Ah
- Determine series cells: 48V ÷ 3.7V ≈ 13 cells
- Calculate parallel strings (using
**3000mAh cells**): 20.83Ah ÷ 3Ah ≈ 6.94 (round to 7)

Result:13S7P configuration, totaling91 cells (13 × 7)

## How many 18650 batteries does it take to make 48V 20Ah?

For a **48V 20Ah pack**:

- Series cells: 48V ÷ 3.7V ≈ 13 cells
- Parallel strings (
**3000mAh cells**): 20Ah ÷ 3Ah ≈ 6.67 (round to 7)

Configuration:13S7P, totaling91 cells (13 × 7)

## How many 18650 batteries would make a 12v 20Ah battery?

For a **12V 20Ah pack**:

- Series cells: 12V ÷ 3.7V ≈ 3.24 (round to 4)
- Parallel strings (
**3000mAh cells**): 20Ah ÷ 3Ah ≈ 6.67 (round to 7)

Configuration:4S7P, totaling28 cells (4 × 7)

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