Smart 4-Cell Li-ion BMS

@mairajali11

With extensive experience in Electrical/Electronics Engineering and PCB Design, I'm confident that I can deliver a high-quality, compact and smart 4-Cell Li-ion BMS device for your college prototype. I've successfully completed projects very similar to yours using TI BQ-series, LTC, and other esteemed parts, and I can customize the design for you accordingly. As you specified, I can provide a fully annotated BOM with globally available part numbers. My expertise with Eagle, Altium, KiCAD, and EasyEDA will ensure a precise and meticulous PCB layout along with Gerber & drill files for maximum compatibility. The design will not only monitor each cell individually but will also balance them during charge while guaranteeing protection against over-voltage/under-voltage, over-current/short-circuit events. Furthermore, my proficiency in embedded systems and programming (C/C++, Python) make me well-equipped to deliver the firmware or a detailed configuration guide you’re looking for. You can count on me to ensure that your desired signal transfers between this advanced BMS to your host ESP32/STM32 through I²C without any hitch. Let my clean, reproducible design help you showcase your prototype confidently at university

@tshibsamuel477

Hi there, I carefully reviewed your smart 1S–4S 18650 BMS requirements, including per-cell monitoring, balancing, over-voltage/under-voltage protection, over-current and short-circuit protection, temperature monitoring, low quiescent current, and communication with an ESP32 or STM32. I am a mechatronics engineer with almost half a decade of experience in embedded electronics, power supplies, PCB design, hardware prototyping, and interfaces such as I2C, SPI, UART, and USB. This background is directly relevant to developing the sensing, protection, host communication, and compact PCB required for your prototype. Because power electronics, embedded hardware, and digital communication interfaces are already part of my core skillset, I can approach the design efficiently while keeping measurement accuracy, protection thresholds, low standby consumption, manufacturability, and firmware integration in mind. Please send me a message so we can discuss the project and start. Best regards, Samuel tshibangu

@Mahmoud00Ibrahim

Hello, I’m an Embedded Hardware Engineer experienced in battery-powered systems, power management, STM32/ESP32, PCB design, and production-ready hardware. I can design your compact 1–4S Li-ion BMS with individual cell monitoring, passive balancing, OV/UV, over-current/short-circuit, and temperature protection. For the BMS architecture, I can evaluate proven TI BQ-series, LTC/ADI, or similar AFE solutions based on the required 1–4S range, accuracy, low quiescent current, balancing method, and I²C accessibility. The design will include: * Individual cell voltage monitoring and balancing * Pack current and thermistor measurement * Hardware protection for OV/UV/OCP/short/OT * I²C interface to ESP32/STM32 with a clear register/configuration approach * Compact 4-cell PCB layout * Complete BOM with globally available MPNs * Gerbers, drill files, and manufacturing package * Firmware hooks/configuration guide if required I’ll also design around your bench acceptance criteria, including ±10 mV cell measurement accuracy, 4.15 V balancing threshold, and the specified protection limits. I can provide the schematic/AFE topology and proposed I²C register structure early so you can verify it fits your firmware timeline before PCB development. Best regards, Mahmoud

@shivkantverma

Hi, Greetings! I am interested in working on your project. Could you please share the design details and technical requirements so we can discuss the project scope and key parameters in detail? I look forward to working with you. Thank you! Shivkant

@mcollinscalz

Hello, Designing a precise, low-quiescent BMS for 1–4S Li-ion battery packs requires robust AFE selection and exact analog front-end isolation. As an Electronics Engineer, I can deliver a clean, university-ready BMS PCB and host library. Proposed Topology & Architecture: AFE IC: TI BQ76920 (or BQ76907) — proven 3–5S AFE featuring built-in internal cell balancing, HW protection logic (OV/UV/OCD/SCD), direct NTC thermistor reading, and low standby current (<20 µA). Communication Interface: Direct I²C bus (CRC-enabled) to your host ESP32/STM32. Register Map & Hooks: Standard BQ-series I²C registers for direct byte reads (0x0C–0x13 for cell voltages, 0x2A for current, 0x2C for temperature). I will provide an easy-to-integrate C/C++ driver library. Deliverables: Complete Schematic & Compact PCB Layout (sized for 18650 holder) Production Gerbers, Drill files, and Global BOM (DigiKey/Mouser part numbers) Modular C/C++ Host Firmware Driver / I²C API for ESP32/STM32 Test & Bench Validation Guide matching your 10 mV & 7 A acceptance checks Turnaround: 5–7 Days I am ready to help you create a high-performing prototype for your university project. Best regards,

@Santoshchaulaga

Hello, I am Santosh Chaulagain, a professional Electrical Engineer and PCB Designer with over 7 years of experience in schematic design, PCB layout, and embedded systems, including ESP32, IoT devices, analog and digital circuits. I have successfully completed multiple projects for clients worldwide, delivering reliable and manufacturable designs. I have carefully reviewed your project requirements and I am confident that I can provide a high-quality solution tailored to your needs. My expertise includes PCB design using industry standards, component selection, BOM preparation, Gerber generation, and design optimization for cost and performance. I always ensure that my designs are fabrication-ready and tested for reliability. I focus on clear communication, timely delivery, and customer satisfaction. I am happy to discuss your project in detail and provide revisions until the final result meets your expectations. Looking forward to working with you. Best regards, Santosh C. Electrical Engineer | PCB Designer | ESP32 & IoT Specialist

@hamzaePCB

One point I’d clarify before selecting the AFE: does the same board need to operate with 1S, 2S, 3S and 4S packs dynamically, or is the final hardware always 4S with fewer cells only during development? This changes the cell-input configuration, protection strategy and how unused channels should be handled. For a 4S design, I’d use a dedicated battery-monitor/protection AFE rather than measuring the cells directly with the ESP32/STM32. I’d first verify the AFE against your ±10 mV measurement target, programmable 4.15 V balancing condition, 4.25/2.5 V protection thresholds, 7 A current sensing and 70 °C thermistor trip. The host MCU would receive per-cell voltage, pack/current and temperature data through I²C, with the required register/configuration sequence documented so you can integrate it into your own firmware. I’ll also size the shunt, protection MOSFETs and thermal/current paths around the 7 A requirement and keep quiescent consumption in mind. Deliverables: schematic, PCB, Gerbers/drills, annotated BOM and I²C configuration/integration notes.

@ThynkLoop

Hi, I can design the smart 1–4 cell Li-ion BMS with individual cell monitoring, balancing, protection, and I²C communication with an ESP32/STM32. I will select a suitable BMS/AFE IC, design the schematic and PCB, and provide the required manufacturing files and communication details. Proposed Approach: Select suitable BMS/AFE IC Design cell monitoring and balancing Add voltage, current, and temperature protection Implement I²C communication Design compact PCB Prepare BOM and Gerber files Verify protection and cell readings Deliverables: BMS schematic PCB layout Gerber and drill files Annotated BOM I²C register/communication guide Firmware/configuration support Testing documentation

@aizaz229

I specialize in Li-ion battery management systems, power electronics, and mixed-signal PCB design in Altium Designer and KiCad. Designing a 1S to 4S smart BMS with tight voltage sensing, active/passive balancing, and comprehensive fault protection requires low-noise Kelvin routing to the current shunt and high-impedance sense lines. For this architecture, I recommend the TI BQ76920 (or BQ76907) Analog Front End paired with back-to-back N-channel charge/discharge power MOSFETs and a low-side sense resistor. The BQ76920 features an integrated 14-bit ADC providing sub-10 mV cell resolution, built-in passive balancing FET drivers, hardware-timed over-current/short-circuit protection, and low quiescent sleep modes. It communicates directly over standard 100 kHz I2C (with optional CRC), exposing a simple register map with dedicated 16-bit registers for individual cell voltages (VC1 to VC4), pack current, and external NTC thermistor measurements. The layout will fit directly beneath or alongside a standard 4-cell 18650 holder, using 2 oz copper pours for the 7A high-current path and Kelvin connections for current sensing and thermistor placement. Deliverables include native CAD files, Gerbers, drill data, a verified BOM, register map documentation, and a working C/C++ driver library with example code for ESP32 and STM32.

@zeel1410

Hi, I can design a compact, fabrication-ready 1–4S Li-ion BMS tailored for ESP32/STM32 integration, including schematic, PCB, Gerbers/drill files, BOM, and I²C interface documentation. For the AFE, I’d evaluate a proven TI BQ-series device such as the BQ76920, selecting the exact part based on the final 1–4S configuration and current requirements. The design would support: • Individual cell voltage monitoring • Passive cell balancing • Pack voltage/current measurement • OV/UV, over-current/short-circuit protection • NTC-based temperature protection • Charge/discharge FET control • Low-quiescent-current operation • I²C host interface The I²C register structure will provide straightforward access to Cell 1–4 voltage, pack voltage/current, temperature, fault status, and balancing status, with ESP32/STM32 firmware examples/configuration guidance. I’ll design the PCB around your four-cell holder, with proper high-current routing, Kelvin shunt sensing, cell-sense filtering, and appropriate clearances. I’ll target your acceptance limits: ±10 mV cell measurement, balancing around 4.15 V, OV/UV around 4.25/2.5 V, 7 A over-current, and 70 °C thermal protection, with documented hysteresis/recovery behavior. Please share the holder dimensions, maximum charge/discharge current, and preferred PCB size so I can finalize the topology and component selection.

@Mayank7245

Hi, I can design a compact 1S–4S Li-ion BMS prototype with ESP32/STM32 integration over I²C, covering cell monitoring, balancing and required protection functions. My approach will use a proven multi-cell battery-monitoring/protection AFE such as a suitable TI BQ-series or equivalent device, selected according to the final 1S–4S requirements. The design will include: • Individual cell voltage monitoring • Passive cell balancing • Over-voltage/under-voltage protection • Over-current/short-circuit protection • Temperature/thermistor monitoring • Pack voltage and current measurement • Low-quiescent-current considerations • I²C interface and simple ESP32/STM32 firmware hooks • Complete schematic and annotated BOM • Compact PCB layout for a 4-cell holder • Gerber + drill files • Register-map/configuration documentation The firmware interface will provide straightforward access to individual cell voltages, pack voltage, current, temperature and protection/status flags. I will design and document the system around your specified bench acceptance criteria, including the ±10 mV cell-voltage measurement target, balancing threshold and protection limits. I can deliver the complete design package within 7 days with clear documentation suitable for university presentation and fabrication. Bid: ₹1,500 Delivery: 7 days Regards, Mayank

@aijob4

I can design a compact 1S–4S smart Li-ion BMS around a proven AFE such as the TI BQ-series, with individual cell monitoring, balancing, OV/UV, over-current/short-circuit and temperature protection. I will create the complete KiCad schematic, 4-cell-sized PCB layout, annotated BOM with globally available components, and fabrication-ready Gerber/drill files. For the host interface, I will prioritize I²C and provide a clear register/firmware interface for ESP32 or STM32 to read individual cell voltages, pack voltage, current and temperature. I will also design the protection thresholds around your specified requirements and verify the schematic against the selected IC's datasheet/reference design before finalizing the PCB. Why me: I have an electronics design background with hands-on experience in PCB design, circuit design, component selection, hardware integration and testing, and I am comfortable working with KiCad and embedded hardware. I will focus on a clean, manufacturable and well-documented design rather than just producing a schematic. The final project will include the source files, BOM, Gerbers, drill files and documentation needed for fabrication and university presentation.

@nehavaddellu

With my vast experience in electronics and a focus on battery hardware R&D, I am the ideal candidate to tackle your smart 4-cell Lithium-ion battery management system (BMS) project. I have extensive hands-on experience developing custom lithium-ion packs, including passive cell balancing and thermal management systems – all of which align perfectly with your project needs. My skills in circuit design and PCB layout will ensure optimal signal integrity, clean power distribution, and tight integration with other systems. In addition to bringing your circuit board ideas to life, I offer a distinct advantage in my ability to create reproducible designs that are ready for fabrication. Having managed the full hardware lifecycle, I understand the importance of a well-documented configuration. Thus, I will provide you with efficient Gerber files, optimized BOMs with readily available part numbers, and assembly data - enabling you to take control and manage your own product at every touchpoint. On top of that, once the hardware design is completed to your satisfaction, I can also help with firmware if a local MCU is used or provide comprehensive configuration guidance for seamless integration with ESP32/STM32 via I²C interface for reliable monitoring of per-cell voltage readings, pack voltage, current, as well as thermistor data to meet your acceptance checks. Let me transform this vital aspect of your collegiate prototype into a confident reality!