Development and manufacturing of custom battery packs, BMS and electronic assemblies in Switzerland.
TEFAG Elektronik AG
CH-8887 Mels, Grossfeldstrasse 5New on Amplifa
About TEFAG
TEFAG Elektronik AG, based in Mels (SG), is a specialized service provider for electronics and mobile energy management developments with its own production facility. The company develops and assembles custom battery packs based on lithium-ion, lithium iron phosphate and lithium polymer cells, including protection circuits (PCM), battery management systems (BMS) and matching charging technology. In addition, TEFAG handles electronics development (circuit design, PCB layout, embedded software) as well as assembly manufacturing up to boxbuilding, including resistance welding of cells, adhesive bonding and polyurethane potting processes. Manufacturing ranges from prototypes to series of over 100,000 units per year, with 100 percent end-of-line testing of every product. Customers come, among others, from medical and laboratory, dental, plumbing, mobile devices, veterinary technology, professional photography, as well as acoustics and hearing aids. TEFAG is a subsidiary of the German RAWE Electronic GmbH and part of the internationally active Demmel Group.
- Site
- Mels
- Processes
- Battery assembly (custom battery packs incl. protection circuit/BMS), Resistance welding of individual cells into battery packs, Adhesive bonding (manual and automated) of battery cells, circuit boards and housings; sealing of, Polyurethane potting of assemblies and battery packs, Population of special components/THT components and hand soldering per IPC, Assembly manufacturing / boxbuilding (screwing, bending processes, battery housing, cable and, End-of-line testing: 100% functional and electrical final testing incl. calibration,, PC-based measuring and testing technology (end-of-line tests, product validation, cycle testing)
- Materials
- Lithium-ion batteries, Lithium iron phosphate batteries, Lithium polymer batteries, Polyurethane (potting), Lithium metal batteries, Lithium polymer batteries (pouch cells)
- Certificates
- ISO 9001, ISO 14001
- Founded
- 1992
- Employees
- 21
- Industries
- Medical & Laboratory (emergency medicine, ambulance), Dental, Building/Plumbing/Gas supply, Mobile devices, Veterinary/Animal care/Agriculture, Professional photography/Camera technology
- 01
Electronics and battery development (hardware, PCB design, embedded software)
- 02
Product qualification and sample/prototype building
- 03
Manufacturing management (supply chain, tooling, documentation)
- 04
Population of special components and THT components, hand soldering per IPC
- 05
Resistance welding of individual cells into battery packs
- 06
Adhesive bonding and sealing (manual and automated)
- 07
Polyurethane potting of assemblies and battery packs
- 08
Assembly and device assembly (boxbuilding)
- 09
End-of-line testing with 100% functional and final inspection
- 10
Battery certification and logistics
Cell Technologies and Materials
Lithium-ion batteries
Cylindrical (18500, 18650, 21700), prismatic and button cells with voltages of 3.6–36 V for standard mobile applications.
Lithium iron phosphate batteries
For higher safety requirements, as custom packs including PCM or BMS.
Lithium polymer batteries (pouch cells)
Plastic-aluminium foil cells for space-critical or flexible battery shapes, including protection circuit.
Polyurethane (potting)
Potting compound for protecting assemblies and battery packs against moisture and wetness.
Locations
Mels
CHDevelopment, production, administration (headquarters)
- Lot size
- Prototypes to 100,000 units/year
- Materials
- Lithium-ion, lithium iron phosphate, lithium polymer
- Resistance welding technology for battery cells
- Adhesive bonding systems (manual and automated)
- Polyurethane potting systems
- PC-based measuring and testing technology / end-of-line testing
- Climate chamber for climatic and lifetime testing
Components and Systems
Inside the production
Industries
Processes & technical limits
| Processes | Tolerance | Max. part | Weight | Lot size | Materials |
|---|---|---|---|---|---|
| Battery assembly (custom battery packs incl. protection circuit/BMS)Assembly | – | – | – | Prototypes – 100'000 units per year | Lithium-ion, Lithium iron phosphate, Lithium polymer |
| Resistance welding of individual cells into battery packsJoining | – | – | – | – | Lithium-ion |
| Adhesive bonding (manual and automated) of battery cells, circuit boards and housings; sealing ofJoining | – | – | – | – | – |
| Polyurethane potting of assemblies and battery packsJoining | – | – | – | – | Polyurethane |
| Population of special components/THT components and hand soldering per IPCAssembly | – | – | – | – | – |
| Assembly manufacturing / boxbuilding (screwing, bending processes, battery housing, cable andAssembly | – | – | – | – | – |
| End-of-line testing: 100% functional and electrical final testing incl. calibration,Testing | – | – | – | – | – |
| PC-based measuring and testing technology (end-of-line tests, product validation, cycle testing)Testing | – | – | – | – | – |
| Electronics development (power electronics, Bluetooth applications, optical measuring systems,Engineering | – | – | – | – | – |
| Optical measuring systems (triangulation distance measurement) incl. light guide and lens assemblyEngineering | – | – | – | – | – |
| Product qualification and sample/prototype building incl. climatic and lifetime testingTesting | – | – | – | – | – |
| Battery certification (UN 38.3, IEC 62133-2:2017, PSE, KC, WERCS, BIS, UL 1642, UL 2054, CCC)Testing | – | – | – | – | Lithium-ion |
| Manufacturing management (tooling, supply chain, documentation, logistics)Engineering | – | – | – | – | – |
| Battery charger development and charging systemsEngineering | – | – | – | – | Lithium-ion |
Additional services
Quality and Certifications
All products are 100% tested for function and quality; the electrical final testing typically includes calibration steps, microcontroller programming and visual final inspection. TEFAG is certified to ISO 9001 and ISO 14001.
| Evidence | Mels |
|---|---|
| ISO 9001 | |
| ISO 14001 |
History
- 1992
TEFAG Elektronik founded by Alex Mauerhofer and Jakob Stark as a service provider for technology consulting, development and manufacturing management.
- 2009
Sale of the company to the German RAWE Electronic GmbH (Allgäu); new managing director Werner Suter.
- 2012
Certification to ISO 9001 and ISO 14001.
- 2019
Approximately 25 employees; battery packs sold worldwide.
- 2023
Over 8 million lithium-ion cells installed (approx. 300 t, 60 MWh).