Open-source tools unlock dead cordless power tool batteries for free
Two open-source projects are now helping users revive cordless power tool batteries locked out by software. Many manufacturers offer no fix beyond buying replacements—even when the cells themselves remain in good condition. The issue affects popular brands like Ryobi and Makita, where minor glitches can disable fully functional batteries.
Modern cordless tool batteries rely on battery management systems (BMS) to track voltage, temperature, and charge levels. These systems can lock out a battery after a brief voltage drop, storage imbalance, or firmware error. Once triggered, the battery becomes unusable, despite its hardware still working.
The Ryobi ONE+ project focuses on reversing these lockouts in Ryobi batteries. Developer Badar Kayani found that a single byte at memory address 0x7E90 controls the lockout status. By resetting this byte to zero, users can restore full functionality. The project provides tools to analyse and modify the firmware directly.
Another effort, the Makita LXT: Open Battery Information (OBI) project, takes a similar approach for Makita batteries. Launched by developer Tobia Tesche in October 2023, OBI uses an Arduino-based programmer to communicate with the BMS. This allows users to diagnose issues and reset lockouts without replacing the battery.
Both projects aim to extend the lifespan of power tool batteries. Instead of discarding locked-out units, owners can now repair them with open-source tools.
The two initiatives give users a way to bypass software restrictions that would otherwise force them to buy new batteries. With simple firmware adjustments, previously unusable batteries can return to service. This reduces waste and offers a cost-effective alternative to manufacturer replacements.
