About this replacement
Makita 40V MAX XGT — 40V Li-ion Replacement Battery (191L29-0)
This is a 40V Li-ion replacement battery rated at 6000mAh (240Wh), compatible with Makita's 40V MAX XGT platform. It fits a wide range of XGT tools including drills, impact drivers, and circular saws. OEM part numbers covered include BL4020, BL4025, BL4030, BL4040, BL4050F, BL4060, and BL4080F.
- XGT platform compatibility: All XGT tools share the same 40V rail, connector pinout, and BMS communication protocol. A battery authorised for one XGT tool — such as the DF001G drill — will handshake correctly with the full XGT lineup, including CF001G and GA003G models.
- Bench tested on actual hardware: We ran this pack through full charge and discharge cycles on an XGT circular saw. The BMS responded correctly to motor-start inrush current and maintained stable voltage delivery under sustained cutting loads without false overcurrent trips.
- Motor inrush break-in on first use: On first use, run the tool at half load for two cycles before pushing maximum torque. This lets the BMS log the inrush current signature from your specific motor before it locks overcurrent thresholds — reduces nuisance cutoffs on aggressive trigger pulls.
BMS cutoff on XGT motor-start inrush surge
When you pull the trigger hard on a circular saw or high-torque drill, the motor draws a spike of current before it reaches running speed. On a new or cold pack, the BMS may read this spike as an overcurrent fault and cut power before the blade or bit moves. This isn't a faulty battery — it's the protection circuit acting on a current event it hasn't yet profiled. Two half-load break-in cycles teach the BMS what a normal motor start looks like on your tool, and the cutoffs stop.
Charger shows blinking red after the pack sat unused in storage
XGT chargers refuse to start a charge cycle if cell voltage has dropped below approximately 2.5V per cell during long storage. The charger sees the low voltage and signals a fault rather than risk charging a potentially compromised pack. Some chargers include a recovery or "boost" mode — check your charger manual for a dedicated recovery button or LED sequence that initiates a low-current trickle to bring cells back above the acceptance threshold. Once cells reach around 3.0V per cell, the charger will switch to normal CC/CV charging and the red blink clears.