Milwaukee battery drm

Milwaukee Tool, a subsidiary of Techtronic Industries (TTI), produces the M18 line of lithium-ion batteries for use with its cordless power tools. These batteries incorporate an embedded system marketed as REDLINK™ Intelligence, which allows the battery & charger to communicate for monitoring of conditions such as cell voltage, pack temperature, & charge status.

Operator manuals describe that Milwaukee battery packs contain protective electronics designed to prevent overload & overheating, & that fuel-gauge LEDs will flash to indicate fault conditions.

Incident

Milwaukee Battery Diagnostic Readout

In August 2024, an independent YouTube investigation demonstrated that Milwaukee M18 batteries store hundreds of bytes of hidden diagnostic data. These logs include over 50 different statistics, such as counts of over-current events, over-temperature events, cell voltage imbalances with millivolt precision, low-voltage cutoffs, total discharge statistics, total charge time, time on charger whilst full, etc. The data can be accessed through undocumented serial commands but is not disclosed in user manuals.

Community reverse-engineering reports published on Hackaday also documented communication traces between batteries & chargers, confirming that undocumented registers store diagnostic histories not available through consumer interfaces.

Some consumers reported that warranty claims were denied when diagnostic data showed overheating events. In online complaints, users alleged that leaving a battery inside a vehicle in hot weather resulted in warranty denial.

Legal context

In 2017, Milwaukee issued a safety notice in consultation with the U.S. Consumer Product Safety Commission (CPSC) concerning the M18 High Demand 9.0 Ah battery pack (model 48-11-1890).

Earlier, in 2007, the CPSC recalled certain Milwaukee battery packs due to rupture hazards that posed laceration risks.

As of September 2025, no publicly reported lawsuits or regulatory actions have been filed regarding the use of hidden diagnostic data in warranty adjudication.

Business context

Milwaukee’s warranty policy covers defects in materials & workmanship but explicitly excludes misuse, abuse, or alterations. These exclusions are broadly consistent with other power tool manufacturers’ practices.

Consumer impact

Consumers have expressed concern that undisclosed logging could void warranties for circumstances outside of their control, such as environmental heat exposure. Community projects have since published open-source tools that allow end users to read diagnostic registers from Milwaukee batteries, giving them access to the same information the manufacturer uses internally. The "M18 HD12" battery series from Milwaukee currently has a 2.1/5 stars score from 522 reviews on their own website, and the "M12 XC6" battery has a 1.7/5 stars score from 321 reviews on their own website and the company's Trustpilot reviews currently sit at 1.6/5 stars for their entire product line and after-sales service, with many consumer complaints that warranty claims on Milwaukee batteries have been denied, even though their batteries were still within the warranty period. Presumably, Milwaukee is downloading the usage logs from consumer's batteries and looking for any possible data-set to deny a warranty claim.

Industry comparison

The use of embedded diagnostic counters is not unique to Milwaukee. Reports indicate that competing brands such as Makita have implemented similar protocols in their lithium-ion batteries. Ryobi (which is owned by Techtronic Industries, which is the same parent company that owns Milwaukee) also uses the same embedded diagnostics in their batteries. The YouTube channel Badar's Workshop, was able to purchase 30 non-functioning or bricked Ryobi batteries on Ebay and got them all working again by simply flashing the code from a non-bricked Ryobi battery onto the bricked batteries ie. no physical repair was necessary, it was simply the DRM which prevented the batteries from being recognised by the Ryobi charger and receiving a charge.

Company response

Milwaukee states that REDLINK is intended to protect tools & batteries from damage due to overload, overheating, & over-discharge. The company has not publicly addressed concerns that hidden diagnostic logs may be used to deny warranty claims.

Analysis

Critics argue that the hidden nature of these diagnostic counters undermines transparency in warranty adjudication, leaving consumers unable to contest warranty denials without access to the same data Milwaukee uses. Advocates for the right to repair cite this as an example of digital rights management in hardware, where the consumer’s ability to control, repair, & assert ownership over a purchased product is limited by undisclosed technical restrictions.

Timeline

• 2007 – CPSC recall of Milwaukee battery packs due to rupture hazard.
• 2017 – Milwaukee issues safety warning for M18 High Demand 9.0 battery in consultation with the CPSC.
• 2023 – Hackaday reports on community reverse-engineering of Milwaukee REDLINK protocol.
• 2024 – YouTube researcher publicly demonstrates hidden diagnostic registers in Milwaukee M18 batteries.