Dyson battery lifespan reduced by design and difficult to repair

Incident

Dyson battery packs contain a Battery-Management System (BMS) with a chip that would be capable of balancing the individual cells. The manufacturer, however, has decided to leave out a few inexpensive but essential resistors, resulting in no balancing to take effect. As a result, the battery pack wears out much quicker than it should.

Even if a user charges (using a third-party charger) and balances the individual cells of a battery pack, or even replaces them, the BMS will still not allow the battery to be charged, because its firmware writes 2 bytes into the configuration memory of the microcontroller that essentially bricks the battery pack.

Impact on consumers

This incident makes the lifespan of the battery packs of Dyson products significantly shorter, forcing people to replace them more often.

Affected product lines

Potentially all product lines newer than V6 are affected by this issue, although more information is required to confirm this.

• V6 and V7 models.
• V10 and V11 models.

Workarounds

Open-source firmware has been written to un-brick the battery pack by overwriting the board firmware for some models using a 3.3V Arduino board.

Warranty

All "cordless vacuums" are covered by a 2-year warranty, which explicitly does not cover "normal wear and tear" on batteries. New replacement batteries come with a 1-year warranty.

Dyson also advertises their "batteries undergo over 2,000 hours of rigorous testing, to strike the delicate balance between energy density, power density and lifespan." This may have the implication they are rated for 2,000 hours of runtime, which, if used for 1 hour per day, is 5.48 years of use.

Replacement batteries

Batteries generally are around $95 - $130 USD and can be a significant percentage of a new or refurbished unit. For example, a replacement battery for a Dyson Cyclone V10 cordless vacuum is $129.99. A Dyson-refurbished unit can be purchased at $219.99 and a new unit at $499.99. A replacement battery's price ranges from 26.0% to 46.4% the price of an entirely functional unit.

Third-party batteries

Dyson states that "Only by using a genuine Dyson battery are you ensuring that your machine continues to work as intended, and that your warranty remains intact." and "Dyson does not warrant the use of any third-party batteries or parts and assumes no liability for any such use of third-party parts or the injuries or damages caused by their use."