LiFePO4 Battery & BMS Design - 01/10/2025 20:33 EDT
Budget: $3,000 – $5,000 AUD
I’m building a compact LiFePO4 pack to drive a new line of portable electronics and need a complete electrical and firmware design that rolls reliable power delivery together with smart, Wi-Fi–enabled monitoring.
Scope
The pack must safely deliver the energy density our product demands while staying light and service-friendly. A custom BMS is central to this: it should expose live cell readings over Wi-Fi so my mobile app can show voltage, temperature, state-of-charge and health in real time.
Core BMS Functions
• Robust over-charge and over-discharge protection
• Continuous temperature monitoring with fault handling
• Active or passive cell balancing to maximise cycle life
• Accurate, per-cell voltage/current sampling available via Wi-Fi
I’m open to your preferred microcontroller or Wi-Fi module—ESP32, Nordic, or a dedicated BMS IC paired with a separate radio are all fine as long as certification pathways for CE/FCC remain clear.
Deliverables
1. Electrical schematics and annotated PCB layout (Altium, KiCad or Eagle)
2. Bill of materials with ordering links and alternates
3. Firmware source with documented API endpoints for Wi-Fi communication (JSON or MQTT is ideal)
4. Test plan covering protection trip points, balancing efficiency and wireless range
5. Brief assembly guide so my contract manufacturer can move straight to prototyping
Acceptance will be based on bench tests that confirm protection thresholds, cell balancing behaviour, and stable Wi-Fi telemetry over 24-hour cycling.
If a staged approach—concept, prototype, then production—fits your workflow, just outline milestone hand-offs and we’ll lock them in.
The ideal is to use Lifepo4 Cells (26650-33A 3,2V 3,3Ah) with 100Ah Capacity in a 4S30P configuration
the battery must be in cylinder form with diameter not exceeding 120mm and the length to be determinate depending on battery layout and isolation material and BMS fitted.
The ability to switch the pack on and off remotely via the communication information to be discussed.
We do not want to add components together like using a Raspberry Pi with added IO and sensors connected we want a PCB designed system.
Scope
The pack must safely deliver the energy density our product demands while staying light and service-friendly. A custom BMS is central to this: it should expose live cell readings over Wi-Fi so my mobile app can show voltage, temperature, state-of-charge and health in real time.
Core BMS Functions
• Robust over-charge and over-discharge protection
• Continuous temperature monitoring with fault handling
• Active or passive cell balancing to maximise cycle life
• Accurate, per-cell voltage/current sampling available via Wi-Fi
I’m open to your preferred microcontroller or Wi-Fi module—ESP32, Nordic, or a dedicated BMS IC paired with a separate radio are all fine as long as certification pathways for CE/FCC remain clear.
Deliverables
1. Electrical schematics and annotated PCB layout (Altium, KiCad or Eagle)
2. Bill of materials with ordering links and alternates
3. Firmware source with documented API endpoints for Wi-Fi communication (JSON or MQTT is ideal)
4. Test plan covering protection trip points, balancing efficiency and wireless range
5. Brief assembly guide so my contract manufacturer can move straight to prototyping
Acceptance will be based on bench tests that confirm protection thresholds, cell balancing behaviour, and stable Wi-Fi telemetry over 24-hour cycling.
If a staged approach—concept, prototype, then production—fits your workflow, just outline milestone hand-offs and we’ll lock them in.
The ideal is to use Lifepo4 Cells (26650-33A 3,2V 3,3Ah) with 100Ah Capacity in a 4S30P configuration
the battery must be in cylinder form with diameter not exceeding 120mm and the length to be determinate depending on battery layout and isolation material and BMS fitted.
The ability to switch the pack on and off remotely via the communication information to be discussed.
We do not want to add components together like using a Raspberry Pi with added IO and sensors connected we want a PCB designed system.
Related categories:
Electronics
Electrical Engineering
PCB Layout
Product Design
MQTT
JSON
Embedded Systems
Prototyping