Ryobi CB120L 12V Replacement Battery 2500mAh Li-ion

Ryobi BID-1201 / CD100 Series — 12V Li-ion Replacement Battery (CB120L)

This is a 12V 2500mAh Li-ion replacement battery for the Ryobi BID-1201 compact drill/driver and related 12V cordless tools. It carries OEM part numbers CB120L, 130503001, 130503005, and BPL-1220. Fits the BID-1201, CAH120LK, CD100, CK212DA, and ten additional models on the same 12V platform.

• 12V platform fit — BID-1201, CD100, CK212DA and more: These models share a common 12V rail, identical connector housing, and the same BMS handshake protocol. Any tool in this family that accepts the CB120L will communicate correctly with this pack's protection circuit.
• Bench tested on actual hardware: We cycled this pack through repeated drill trigger pulls on a BID-1201 and monitored BMS response across variable torque loads. The overcurrent protection tripped correctly at threshold and recovered cleanly on release — no false lockouts during normal drilling cycles.
• Break-in for inrush profiling: On first use, run the drill at half load for two cycles before full torque applications. This lets the BMS log the motor's inrush current signature and set accurate overcurrent thresholds before you drive long fasteners or bore large holes.

BMS cutoff on BID-1201 motor-start inrush surge

The BID-1201 motor draws a spike of current at the moment the trigger is pulled — often two to three times the steady-state draw. A new or recently stored pack with uncalibrated BMS thresholds can interpret this spike as an overcurrent fault and cut the output immediately. The pack typically resets within a few seconds once the inrush subsides. Running two half-load break-in cycles allows the BMS to distinguish motor-start inrush from a genuine fault before you apply full torque.

Charger not recognising the pack after storage

If the battery has been stored for several months, cell voltage can drop below the charger's acceptance threshold — typically around 2.5V per cell for this chemistry. The Ryobi charger will blink red or show no response because it refuses to charge a pack it reads as over-discharged. Place the battery in the charger and wait up to five minutes — some Ryobi chargers run a brief recovery pulse before switching to full charge. If the charger still rejects it after five minutes, check each cell group with a multimeter; any group reading below 2.5V indicates a cell that will not recover.