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Lithium Battery Bank Calculator

Design your DIY lithium battery pack for car audio. Vendor C-rates are derated by operating environment to reflect real-world thermal limits.

Cell Selection

Headway 40152S

LiFePO4

Popular car audio cell, excellent cycle life

Voltage:3.2V
Capacity:15Ah
Max Cont:3C (45A)
Max Pulse:30C (450A)
Weight:370g
Ri (per cell):3.0

Operating Environment

Vendor C-ratings are often measured under ideal lab conditions. Select your actual operating environment to derate the maximum current accordingly.

Pack Configuration

Rec: 4S for 14V
4S
12.8V nominal → 14.6V charged
Rec: 14P for 300A
4P
60.0Ah total capacity

Target System Requirements

V

12–16V typical for car audio

A

Continuous amps from your system

Bus bars + terminals + contact patches
1.5

1.0–1.5 mΩ = clean build with torqued hardware. 3.0–5.0 mΩ = ring terminals, oxidized contacts, or long bus bars.

Action Required: Define Thermal Environment

Lithium cells fail violently under thermal stress. Vendor C-rates are measured under ideal lab conditions — not sealed in a trunk at 140°F. You must select your operating environment before maximum discharge rates can be calculated.

This selection can be changed at any time using the Operating Environment panel on the left.