Battery event logging
Log and monitor battery parameters to ensure safety, optimize charging and increase lifetime
Higher capacity batteries consist of a fleet of serially and parallelly assembled cells. Monitoring the vital parameters of each battery cell over its lifecycle ensures the safety of the system, optimized charging, and increased lifetime of each cell.
The BMS needs to log the vital parameters like voltage, current, temperature, and others to derive information on actual cell capacity, SOC, SOH, power consumption (charge/discharge), remaining operating time of cell, etc. To store this data, this can either be done by the uController and its embedded non-volatile memory (NVM) directly or using a fast-write, high endurance NVM as the data need to be retained when the battery is switched off in a controlled or uncontrolled fashion. SoC and SoH calculations rely on previous state information of the cell and discharge rate. Excelon F-RAM allows capturing this data instantly while providing high endurance for continuous writes. It reliably stores critical records on battery status, consumes low power, and is ASIL-B compliant for additional safety of the system.
Besides the immediate processing of acquired vital parameters and battery state data logging the BMS could offer the additional capability to record data for later extraction of typical mission profiles. Based on those recorded mission profiles and advanced machine learning algorithms the battery could be performance-tuned or proactively pre-conditioned when an acquired load scenario occurs. In addition, the data logging could also be seen as flight-recorder like black-box, which continuously records all relevant battery data to track-back root causes of malfunctions, clarify warranties in case of (hazardous) incidents or simply support 'pay-per-use'-type new business models.
If the 'to-be-stored' data on BMS events and operational parameters have to be treated in a highly secure fashion, this can be handled by the embedded security functions of the uController (such as the HSM for Infineon's AURIX™ family) directly or additional extended Semper™ Secure NOR Flash memories. Semper™ Secure Flash protects your data through its secure regions, secured transactions, and secured identity. It delivers security, safety, and reliability to automotive and other systems at a low total-cost-of-ownership. This advanced, secured, and easy-to-use NOR Flash device protects code and data from hackers with unparalleled system integrity.
To learn more about how Semper Secure NOR flash can protect your BMS data, please read our white papers:
ExcelonTM F-RAM™, like any other nonvolatile memory technology, is subject to physical degradation that can eventually lead to device failure if not addressed appropriately. F-RAM write/read endurance and data retention are the two end-of-life (EoL) parameters to specify its reliability and performance in a system. Learn more about the F-RAM data retention performance at various operating temperatures and find a method and guidance to accurately calculate the system’s EoL based on its operating temperature profile. Check the application note.
- Datalogging in Battery Management Systems:
- Real-time log of vital parameters like voltage, current, temperature etc.
- Real-time log of SoC, SoH, charge/discharge cycles etc.
- Data collection for predictive maintenance of battery pack
F-RAM for Automotive markets provides fast writes at full interface speed. F-RAM does not have any write delays and data is instantly nonvolatile. Traditional nonvolatile memories have delays of 5 or more milliseconds before data becomes nonvolatile. If power is disrupted, pending data is lost unless the system has extra capacitance or batteries to keep the system on until data is stored.
F-RAM offers virtually unlimited endurance of 100 trillion read/write cycles. Traditional nonvolatile memories typically have less than 1 million cycle endurance, forcing system designers to use complex wear-leveling routines and up to 4x more density to prolong the lifetime of these memories.
