Battery Pack Calculator
DIY Battery Pack, BMS Configuration and Cell Calculators
BatteryPackCalc is a free toolkit for designing and validating DIY lithium battery packs for e-bikes, electric scooters, EV conversions, and home power walls. Each calculator solves one piece of the build. The S/P configuration tool turns a series and parallel count into pack voltage, capacity, and energy in watt-hours; the C-rating tool converts a cell's rated C into maximum continuous current and power; and the BMS cutoff tool maps NMC, LFP, or LTO chemistry onto the over-voltage, under-voltage, and over-current thresholds your protection board should use. The nickel strip tool sizes interconnects against a conservative ampacity, while the internal resistance, charge time, and cell heat tools predict voltage sag, CC-CV charging duration, and the heat each cell sheds under load. Every result is derived from the same formulas shown in each tool's guide, so you can follow the math, plug in your own cell datasheet figures, and cross-check a design before you ever pick up a spot welder.
- S/P Configuration — Calculate pack voltage, capacity, and energy from cell configuration
- C-Rating Calculator — Calculate maximum discharge current and power from C-rating
- Nickel Strip Current — Calculate nickel strip current capacity and resistance
- Pack Internal Resistance — Pack impedance, voltage sag, and power loss
- Charge Time Calculator — Estimate CC-CV charge time
- Cell Heat Calculator — Cell and pack heat dissipation under load
- BMS Cutoff Voltage — OVP/UVP/OCP settings for NMC, LFP, LTO
Read More
- Series vs Parallel Battery Connections Explained | BatteryPackCalc
- Lithium Battery Safety Guide for DIY Builders | BatteryPackCalc
- How to Choose the Right BMS for Your Battery Pack | BatteryPackCalc
- Spot Welding Basics for DIY Battery Packs | BatteryPackCalc
- Why Cell Balancing Matters in Lithium Battery Packs | BatteryPackCalc
- C-Rating Explained: What It Means and How to Use It | BatteryPackCalc
- Battery Enclosure Thermal Management Guide | BatteryPackCalc
Popular Battery Pack Configurations
- 36V 10Ah E-Bike Pack (10S3P)
- 48V 15Ah E-Bike Pack (13S4P)
- 52V 20Ah E-Bike Pack (14S5P)
- 72V 30Ah EV Pack (20S5P)
- DIY Powerwall 14S4P
- Electric Scooter 13S4P
- DIY 18650 Pack 10S3P
- LiFePO4 16S2P Pack
- 24V 7Ah E-Bike Pack (7S2P)
- High-Power 20S6P Pack