WATTALPS and SERMA SAFETY & SECURITY cooperate since 2018 on the functional safety development of the WATTALPS Battery Safety Management (BSM), which is the electronic subsystem ensuring the safety in WATTALPS Battery Management System (BMS).

This collaboration resulted in the development of a highly reliable Battery Safety Management, ready to reach the highest requirements of WATTALPS targeted markets.

The last part of this long term cooperation has consisted in the assessment by SERMA SAFETY & SECURITY of the hardware metrics of the WATTALPS BSM. Following ISO 26262 standard, this analysis consists in evaluating for each of the 770 components of the BMS, all possible faults, their consequences, and the detection of the dangerous ones by embedded safety mechanisms.

You will find in the table here under an extract of the metrics of WATTALPS BSM assessed by SERMA Safety & Security. The WATTALPS BSM includes the capacity to open the main battery contactors to put the battery in a safe state. To keep the battery in a safe operating zone, the following components are included in the BSM:

  • Slave board and connection to battery module
  • Master board, software and communication to slave board
  • Junction box
  • Battery heating management
  • Dielectric fluid management
  • Interface with application in case of a fault detection.


Unexpected event SPFM* LFM* PMHF* Achievable ASIL*
Fire due to overvoltage due to wrong cell voltage measurement 99,50% 98,12% 8,67×10-9 D
Fire due to overtemperature due to wrong cell temperature measurement 99,01% 97,99% 7,58×10-9 D
Fire due to overcurrent due to wrong current measurement 98,02% 96,77% 2,56×10-8 C

* These metrics are valid for a given configuration and mission profile and could vary upon application.



WATTALPS designs, assembles and sells high performance modular batteries for heavy duty equipment. WATTALPS batteries use an innovative solution combining immersion cooling and modularity to provide high performance and long life to various types of machines.

WATTALPS batteries are designed to be easily reused in second life and then, easily recycled. WATTALPS batteries also come with connected services to optimize aftersales second life and fleet management.

WATTALPS batteries are designed for rough environment and heavy duty applications, like construction equipment, material handling, logistics, agriculture or maritime applications.




SERMA Safety & Security is the single point of contact for the security and operational safety of products and IoT, industrial, embedded or information systems. The company benefits from an expertise developed over 20 years in these trades. The offer of a combination of expertise, evaluation and advice is adapted to the needs of the designers and users of these different systems.

  • Security laboratory
  • Cybersecurity expertise and consultancy
  • Expertise and advice in operational safety

The studies carried out by the experts relate to systems or software having operational reliability constraints. SERMA Safety & Security offers its expertise to manufacturers, contractors and certification authorities who needs to develop, validate, approve or certify their systems and software. This dependability study process is centered around four main study points: the reliability study, the availability study, the maintainability study and the safety study.

In addition to these various activities, the company offers training according to the product and/or system cycle. Covering the awareness, operational use, testing, design, safety and security and design phases.

Geographically present on 7 sites in France, the company has nearly 220 employees and generates a gross sales of more than 31 million euros. It is one of the subsidiaries of the SERMA Group.