Adding Wireless AP for WIFI config.

[lorenzo620]

Hello Stuart,

First, I want to express my gratitude for the incredible work you've done with the DIY BMS project . Your system has been instrumental in effectively managing my energy storage solutions. However, I've identified a couple of areas where the system could be enhanced, and I'd like to propose these improvements for integration into the official release.

1. Wi-Fi Access Point Mode on First Boot and Network Loss

One challenge I've encountered is the inability of the DIY BMS to create an access point (AP) on first boot or when the configured wireless network is unavailable. Recently, I changed my wireless router and, without a cable to connect to the DIY BMS, I couldn't update the Wi-Fi credentials. This resulted in a two-day delay until I could purchase a cable and reconfigure the system.

Proposal:

Implement a feature where the DIY BMS automatically creates a Wi-Fi access point if it cannot connect to the configured network on boot. This would allow users to connect directly to the BMS via Wi-Fi to update network settings without the need for a physical connection.

2. Precharge Relay Functionality

In many modern Battery Management Systems, there are typically three contactors: one for charging, one for discharging, and another for precharging. Incorporating a precharge function into the DIY BMS would enhance its compatibility with larger and more complex battery systems.

Proposal:

Introduce a user-configurable timer for a precharge relay , one of the solid state relays can be used for this. Operational Sequence:

1. Upon power-up, the BMS waits until the system is stable and checks for any triggered alarms. 2. If no alarms are detected, the BMS closes the precharge relay for a user-defined duration (X seconds). 3. After the precharge period, the BMS opens the precharge relay and then closes Relay 1 and Relay 2 for normal operation.

This functionality is critical for systems utilizing high-capacity batteries and inverters, where precharging ensures safe and reliable startup by preventing inrush currents that could damage components. In my setup, I use two contactors and an IGBT bridge to control charging and discharging, and this configuration has been operating flawlessly for over a year continuously.

Additional Notes:

• Over the past 240 days, I've been using modified firmware by Meningd with intra-CAN communications, data aggregation, and high availability features—all without a single reboot. My system includes three DIY BMS units running in parallel with 4 x 16S packs on each BMS totaling around 180Kwh of LFP energy storage.
• At a friend's installation, there are six DIY BMS units running in parallel with the same firmware, achieving over 180 days of uptime without faults or reboots. His setup includes seven 16S packs on each BMS, totaling around 600 kWh of LFP energy storage.
• Both my friend and I have extensively tested the modified firmware developed by MENINGD by deliberately triggering various fault scenarios to evaluate how the BMS responds in different conditions. Despite our best efforts to "break" the system, we have not encountered any major flaws in the code. It performs flawlessly, demonstrating stability and reliability in diverse scenarios.
• While we agree that the code could benefit from additional refinement and enhanced safety features, we acknowledge that MENINGD cannot do it all by himself. The foundation he has built is exceptionally solid, and we believe his work deserves recognition and further development to elevate the system's capabilities even more.

Would it be possible for you to collaborate with MENINGD to integrate his modifications and ideas into the official DIY BMS release? His work demonstrates exceptional stability and functionality, and with your expertise, the system could reach new levels of reliability and safety, benefiting the entire DIY BMS community.

Thank you for considering these suggestions. I'm more than willing to assist with testing or provide further details if needed.