About this replacement
Philips Lifeline Systems 6800XT Communicator — 3.6V Ni-CD Replacement Battery (1870107)
This is a 3.6V 1000mAh Ni-CD battery for the Philips Lifeline Systems 6800XT Communicator. The 6800XT is a personal emergency response system used by elderly and at-risk individuals to contact emergency services via a wearable pendant and base unit. This battery maintains the communication link that the system depends on.
- 6800XT base unit compatibility: The 6800XT uses a 3.6V Ni-CD cell with a specific connector and BMS handshake tied to the OEM chemistry profile. Cross-referencing part numbers 1870107, AMED0151, MED0151, and B11602 confirms this cell matches that electrical profile without requiring firmware changes.
- Bench tested on actual hardware: We cycled this cell through a full charge and load test on the 6800XT platform. The BMS accepted the cell, completed its verification sequence, and flagged no fault codes under the device's standby and active transmission load profile.
- Post-installation self-test cycle: After fitting this battery, let the 6800XT complete its full power-on self-test without interrupting the sequence. Medical alert devices run a BMS verification at startup — cutting power mid-cycle locks in a false battery fault that persists until the next clean reboot.
Why the 6800XT charges normally but still triggers a low-battery alarm
The 6800XT's BMS sets its pass threshold against the OEM cell's known charge curve. A new replacement cell hasn't yet built the internal history the BMS uses to confirm chemistry compliance. On the first one or two cycles, the BMS may flag the cell as marginal even when voltage reads correctly. Running one complete charge-discharge cycle lets the BMS recalibrate its threshold against the actual cell. After that cycle, the alarm clears on its own.
6800XT won't power on after the battery sat unused before installation
Ni-CD cells self-discharge in storage, and if the cell drops below the 6800XT's BMS recovery floor — roughly 3.0V — the device won't boot at all. The BMS interprets that voltage as a dead or shorted cell and blocks startup. Connect the unit to mains power and leave it on charge for a minimum of 14 hours before attempting to power on. If the device still won't boot after a full charge, check the terminal voltage at the battery contacts — it should read at least 3.5V before the BMS will release the startup lock.