ARRIS TM602G/115 Replacement Battery 7.4V 3400mAh BPB022S

ARRIS TM602G/115 & TM822G Series — 7.4V Li-ion Replacement Battery (BPB022S)

This 7.4V 3400mAh Li-ion battery replaces the backup cell inside ARRIS cable modems including the TM602G/115, TM02AC1G6, TM822G, and TG862G. It restores the modem's ability to power VoIP and low-bandwidth services during a mains outage. OEM part numbers BPB022S, BPB024, BPB024H, BPB026S, 49100160JAP, and ARCT00777M all cross to this cell.

• TM-series modem compatibility: These modems share a 7.4V two-cell Li-ion bay with a common connector and BMS handshake. The firmware on each model polls the battery over the same internal protocol, so one cell covers the full listed range without hardware modification.
• Bench tested on actual hardware: We cycled this cell through the TM822G's charge controller and confirmed the BMS accepted the new cell within one full charge pass. Voltage held steady at 7.4V nominal across the discharge curve with no mid-cycle cutoff events.
• First-cycle modem charge protocol: After installation, leave the modem plugged in for a full 4 hours before triggering any outage test. The modem's firmware runs a capacity-check sequence on the new cell and will not commit the battery to backup duty until that sequence completes.

Battery self-test failing immediately after swap

ARRIS cable modems run an automatic self-test shortly after a new battery is detected. If the cell hasn't reached a sufficient state of charge, the test returns a fail result and the modem logs a battery fault. This isn't a defective cell — it's the firmware rejecting a battery it hasn't fully profiled yet. Allow 4 hours of uninterrupted mains power after installation before the modem re-runs its test cycle.

VoIP drops during outage while internet stays up

Data connectivity and VoIP do not draw the same sustained current from the backup battery. Internet traffic runs at lower average power, so the modem can maintain a data path even when the battery can no longer sustain the higher continuous load that VoIP telephony requires. A degraded original battery often shows this split failure — data survives, calls drop. Replacing the cell and allowing a full charge cycle before the next outage resolves the imbalance. After installation, confirm the modem reports battery status as "Normal" in the admin panel at 192.168.100.1 before relying on it for calls.