Embedded Systems and Design & Development - Feb 11, 2026 | Afternoon | VisionAstraa EV Academy

Battery Pack Calculation Overview

Introduction to the Problem

• The speaker welcomes participants and sets the context for solving a battery pack problem, specifically focusing on an LFP (Lithium Iron Phosphate) battery pack.

• Participants are encouraged to engage actively, having received a data sheet related to the LFP pack.

Data Sheet and Initial Calculations

• The session aims to calculate parameters for a 50 kW LFP high voltage car pack, similar to previous calculations done for an NMC (Nickel Manganese Cobalt) pack.

• Key parameters identified for calculation include: number of series (S), number of parallel (P), charging C rating, discharging C rating, BMS selection, onboard charger selection, and total cell count in the battery pack.

Step-by-Step Calculation Process

Number of Series (S)

• Participants are prompted to confirm their progress with calculations; responses indicate varying levels of completion.

• To find S, the formula used is 50 kW converted into watts divided by the nominal voltage. For HV packs, this is set at 300 volts.

• The nominal voltage for LFP cells is confirmed as 3.2 volts; thus S is calculated as 300/3.2 = 93.75 , rounded up to 94.

Number of Parallel Packs (P)

• The assumption made for AH capacity is around 100 AH; further calculations lead to determining P based on total AH required from the battery pack.

• A rough estimate gives approximately 166 AH needed per cell; rounding leads to a requirement of about 200 AH total which results in P = 2 .

Current Ratings

Charging and Discharging Currents

• Discussion shifts towards calculating charging and discharging currents based on data sheet specifications rather than arbitrary values.

• The rated discharge energy from the data sheet indicates that each cell can discharge up to 300 watt-hours.

Total Battery Pack Considerations

• With two cells connected in parallel yielding a total capacity of 200 AH, questions arise regarding maximum current output based on individual cell ratings.

This structured approach provides clarity on how participants can navigate through complex calculations related to battery packs while ensuring they understand each step's significance within the overall process.

Class Update and Data Sheet Instructions

Instructor's Health and Class Continuation

• The instructor expresses that they are not feeling well, making it difficult to continue the class today.

• A decision is made to postpone the session until tomorrow.

Student Assignments

• Students are encouraged to work on calculations or any tasks possible with the provided data sheet in the meantime.

• The instructor hopes all students have access to the data sheet link; if not, they should search for it online.