About this replacement
Porter Cable PC18AG Series — 18V Ni-MH Replacement Battery (PC18B)
This is an 18V 3000mAh Ni-MH replacement battery for the Porter Cable PC18AG and related 18-volt cordless tool range, including the PC18AL, PC18CHD, and PC18CSL. It slots into the same battery bay and connects to the same contacts as the original PC18B pack. Voltage is 18V; capacity is 3000mAh (54Wh).
- PC18 platform compatibility: These models share the same 18V rail, battery bay geometry, and contact layout. The BMS handshake across this range uses the same thermistor signal line, so one pack covers all listed models without modification.
- Bench tested on actual hardware: We cycled this pack through a PC18AG drill and a circular saw from the same platform. The BMS held through repeated trigger pulls and sustained cutting loads without tripping overcurrent protection.
- Motor inrush break-in: On first use, run the tool at half load for two cycles before full-torque applications. This lets the BMS log actual inrush current from your specific motor before locking overcurrent thresholds — reduces false trips on worn tools with higher start currents.
BMS cutoff on drill and saw motor-start inrush surge
Every trigger pull sends a short inrush spike through the pack — on a drill or circular saw, that spike can be three to five times the running current. A fresh Ni-MH BMS that hasn't seen your tool's motor profile yet may read this as an overcurrent fault and trip. If the pack shuts off on the first hard pull but recovers after a second, that's the BMS calibrating, not a defective cell. Two half-load warm-up cycles clear the threshold and the pack will hold through full-torque starts afterward.
Charger blinking red and refusing to accept the pack after storage
Ni-MH packs left on a shelf for several months self-discharge below the voltage floor that most Porter Cable chargers require to begin a charge cycle. The charger sees a pack voltage it doesn't recognise as safe and blinks red instead of starting. The fix is a slow trickle charge — if your charger has a conditioning or recovery mode, use it; otherwise, a compatible universal charger set to 200–300mA will bring the cells back above the acceptance threshold. Once the pack reaches approximately 15V open-circuit, the standard charger will recognise it and complete the cycle normally.