About this replacement
Exogen Bone Stimulator — 3.7V Li-ion Replacement Battery (81087060C)
This is a 3.7V 750mAh Li-ion cell that replaces the OEM battery in the Exogen Bone Stimulator (part number 81087060C). It fits the portable handheld unit used in prescribed fracture and post-surgical bone healing protocols. Capacity matches the original at 750mAh (2.78Wh) — no modification to the device is required.
- Exogen Bone Stimulator fit: The Exogen system runs a fixed daily treatment cycle at low continuous draw. This cell matches the original voltage rail and connector, so the BMS handshake completes correctly on power-up without triggering a battery fault.
- Bench tested on actual hardware: We ran this cell through the Exogen power-on self-test sequence. The BMS accepted the cell, charge acceptance was verified, and the unit completed its boot cycle without a fault flag on first use.
- Post-swap self-test protocol: After installing this battery, let the device run its full power-on self-test without pressing any buttons or interrupting the sequence. The Exogen BMS runs a verification check at startup — interrupting it can set a false battery fault that persists until the next complete reboot.
Why the Exogen alarms low battery immediately after a confirmed full charge
The Exogen charge IC applies a conservative acceptance threshold calibrated to the original OEM cell's internal resistance profile. A new replacement cell presents a slightly different impedance signature on the first cycle, which the BMS can read as below its minimum threshold even when the cell is fully charged. This is not a defective battery — it is the BMS learning the new cell's characteristics. Run one complete charge-to-discharge-to-full-charge cycle, and the alarm clears. After that cycle, the unit reads the cell accurately at 3.7V nominal.
Device will not power on after replacement cell sat in storage
Li-ion cells self-discharge during storage. If the cell voltage has dropped below roughly 2.5V, the Exogen BMS enters a protection state and blocks power-on entirely — this is a safety cutoff, not a hardware fault. Connect the device to its charger and leave it for at least 30–60 minutes before attempting to power on. The charge IC uses a low-current pre-charge trickle to recover the cell back above the BMS recovery threshold before switching to full charge rate. Once the indicator shows charging activity, the cell is recovering — do not interrupt it.