Dyson battery lifespan reduced by design and difficult to repair

Incident

Dyson battery packs include a Battery Management System (BMS) equipped with a chip capable of balancing the individual cells. However, the manufacturer has chosen to omit a few inexpensive but essential resistors, preventing the balancing function from working as intended. As a result, the battery pack degrades much faster than it should.

Even if a user attempts to charge and balance the individual cells using a third-party charger, or replaces the cells entirely, the BMS will still prevent the battery from charging. This is because the BMS firmware writes two bytes into the microcontroller's configuration memory, effectively rendering the battery pack unusable.

Impact on consumers

This issue significantly reduces the lifespan of Dyson battery packs, causing them to wear out much faster than they otherwise would. As a result, customers are forced to replace their battery packs more frequently.

Affected product lines

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

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

Workarounds

Open-source firmware has been developed to un-brick the battery pack by overwriting the board firmware on 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."