Bank Hardeners

bank-hardenerSBE’s Bank Hardener™, offers a smaller, less expensive, more powerful and more reliable method of meeting your inverter or power conversion DC-link requirements. Enabled by the annular form factor Power Ring Film Capacitor™, the Bank Hardener™ allows you to:

  • Reduce up-front costs by using fewer capacitors and smaller bus structures,
  • Reduce maintenance costs by extending the life of your capacitor bank and reducing failure points,
  • Extend the life of the bank by two to three times,
  • Increase system efficiency by lowering capacitor losses,
  • Get more power out of your existing capacitors.

Based on the tried and proven “low pass filter” concept in circuit board design, the Bank Hardener combines the superior current capability of Power Ring Film Capacitors with the capacitance capability of aluminum electrolytic capacitors. The low ESL of the Power Ring coupled with an optimized bus structure drive the higher frequency, inverter stage ripple current through the Power Ring, thus keeping the aluminum electrolytic capacitors cool by protecting them from heat inducing higher frequencies.

As illustrated below, as ripple current component frequencies increase, more of the current is absorbed by the Power Ring (click on graph to enlarge).



The higher frequency components of the ripple current cause the majority of the temperature rise in aluminum electrolytic capacitors. By keeping them cool, the capacitors last longer. As shown below, when hardened by a 1000µF Power Ring, the life of a 30,000µF aluminum electrolytic capacitor bank will increase from 110,000 hours to 250,000 hours. By increasing the Power Ring to 1500µF, the life of the aluminum electrolytic bank is increased to over 320,000 hours.


The annular form factor Power Ring is the key to the Bank Hardener. The large diameter and short height of the Power Ring present a short current path, which results in very low ESR. Industry-leading ESR, ESL and an optimized bus structure, offer ripple current the path of least impedance for a given capacitance value. The large surface area and low ESR (low losses) combine to offer the lowest hotspot temperature rise available (click on graph to enlarge).