About this replacement
Lincoln 1201 Automotive Grease Gun — 12V Ni-MH Replacement Battery (218-787)
This is a 12V, 2100mAh Ni-MH replacement battery for the Lincoln 1201 cordless grease gun and compatible 12V models including the 40394 and other units sharing the 218-787 pack format. It slots into the same battery bay as the original and connects to the same charging contacts. Voltage and cell chemistry match Lincoln's factory spec exactly.
- 1201, 40394, and 218-787 platform fit: These Lincoln grease gun models run on the same 12V battery rail with an identical connector footprint and BMS handshake protocol. Swapping between them requires no adapters — the contact block and latch geometry are shared across the platform.
- Bench tested on actual hardware: We ran this pack through trigger-pull cycles on a 1201 grease gun, monitoring the BMS response to motor-start inrush current. The overcurrent protection reset cleanly after each cycle, and cell voltage held steady across repeated pump strokes without unexpected cutoff.
- First two cycles on a grease gun: On initial use, run the gun at partial stroke — short trigger bursts rather than continuous pumping — for the first two full charge cycles. This lets the BMS calibrate inrush thresholds against the motor's actual load profile before you run sustained high-torque pumping jobs.
BMS cutoff on motor-start inrush in the Lincoln 1201
Every trigger pull on a cordless grease gun generates a brief inrush spike as the motor overcomes the grease pump's static resistance. On a fresh or recently stored Ni-MH pack, internal resistance is temporarily elevated, which amplifies that spike from the BMS's perspective. If the BMS reads the surge as an overcurrent event, it trips the protection circuit and the gun stops mid-stroke. Releasing the trigger for three to five seconds resets the latch and lets you continue.
Charger not recognising the pack after storage
Ni-MH cells self-discharge in storage, and if a pack sits long enough, cell voltage drops below the charger's acceptance threshold — typically around 1.0V per cell. The Lincoln charger reads this as a fault and refuses to begin a charge cycle. To recover the pack, place it on a known-good charger that includes a trickle or recovery mode, which will slowly bring cells back above the acceptance floor. Once cell voltage climbs above approximately 1.1V per cell, the main charge cycle will start normally.