Canon LB-51 BJ-I70 Replacement Battery 10.8V 2300mAh

Canon BJ-I70 / BJ-IP90 Series — 10.8V Li-ion Replacement Battery (LB-51)

This 10.8V, 2300mAh lithium-ion battery replaces the Canon LB-51 (also listed as 0074B001, LK-51B, LB-50, LK-51) in the BJ-I70, BJ-I80, BJ-IP90, and Pixma I70 portable inkjet printers. It restores cordless print capability when the original cell no longer holds charge. Voltage and capacity match Canon's factory specification exactly.

• BJ-I70 / BJ-IP90 platform fit: These models share the same 10.8V three-cell lithium pack, battery bay connector, and BMS handshake protocol. One battery covers both the BJ-series and the Pixma I70 line because the power management circuit is common across all variants.
• Bench tested on actual hardware: We ran this pack through the BJ-I70 power-on sequence, print head initialisation, and a multi-page print cycle. The BMS held communication throughout — no false low-battery flags, no mid-cycle cutoff under combined motor and heating element load.
• First-run charging on Canon portable printers: Charge this battery to full before the first print run. The print head motor and heating element together draw peak current at startup. A partially charged cell can trigger the BMS cutoff before the first page clears — not a fault, just insufficient starting voltage.

Why the BJ-I70 stops mid-print rather than showing a low-battery warning

The BJ-I70 manages power through a BMS that monitors cell voltage in real time. When the heating element and feed motor fire simultaneously, combined current draw can spike the internal resistance of a degraded or partially charged cell enough to pull voltage below the BMS cutoff threshold. The printer shuts down instantly — no warning, no graceful stop. This is not a printer fault. It is the BMS protecting the cells from over-discharge at the moment of peak load. A fully charged replacement cell with healthy internal resistance clears that threshold during the startup spike.

Printer shows full bars on new battery but won't start a print job

A freshly installed battery can display full charge on the indicator while still failing to drive the print cycle. This happens when the battery has shipped in a deep-discharged state and the Canon battery gauge reads stored BMS data rather than a live cell measurement. Connect the printer to the charger and run a full charge cycle from zero — allow the charger to terminate naturally. Once charge completes and resting voltage stabilises above 12.0V on the pack, the print job initialisation sequence will clear normally.