Designing reliable electronics for vehicles has always meant managing a tough set of conditions: wide temperature swings, constant vibration, and strict space constraints. As electrification spreads through powertrain modules and auxiliary systems, those demands only increase. Capacitors, though often overlooked, sit right in the center of these challenges. They must deliver high capacitance and ripple current handling without taking up more real estate than a tight module allows.
TDK has introduced two new capacitor series aimed directly at this problem. The B41699 and B41799 families of aluminum electrolytic capacitors are built in an ultra-compact axial form, engineered to handle operating temperatures up to +140 °C. They target automotive applications such as electric power steering, fan control, and transmission electronics where both thermal stress and vibration are everyday realities.
High Capacitance in a Smaller Package
The new devices cover rated voltages of 25 V and 35 V with capacitance values ranging from 1800 µF to 13,000 µF. Ripple current ratings reach up to 34.6 A at 10 kHz and +125 °C case temperature, supported by low ESR and more than 4000 hours of useful life under rated conditions. This combination lets engineers reduce the number of capacitors needed in a given design while still meeting power stability requirements.
Built for Vibration and Long Service Life
Vibration resistance is another key design feature. The capacitors are specified to remain stable under loads of up to 60 g, a critical factor in modules exposed to mechanical shock and road-induced vibration. TDK’s SIKOREL-based construction extends storage life to as long as 15 years at +35 °C, helping ensure reliability across an entire vehicle lifespan. Both families meet RoHS requirements and comply with AEC-Q200 automotive standards.
Flexible Mounting Options
The B41699 version uses a traditional axial-lead design, while the B41799 introduces a soldering star configuration. Together, they allow engineers to mount the capacitors horizontally, vertically, or into busbar systems depending on packaging needs. Sizes range from 16 mm x 25 mm to 21 mm x 49 mm (diameter x height).
What This Means for xEV Platforms
For engineers developing xEV systems, especially 12-volt board nets within hybrid and electric vehicles, the ability to achieve high capacitance in a compact and vibration-resistant package helps simplify design without trading off performance. As vehicle electronics grow more complex, component-level improvements like these play an important role in keeping modules smaller, lighter, and more reliable.
Further information on the products can be found at www.tdk-electronics.tdk.com/en/alu_axial
