About this replacement
SurgiTel Eclipse EHL65 / Odyssey Analog — 7.4V Li-ion Replacement Battery (25458)
This is a 7.4V 2600mAh lithium-ion battery for the SurgiTel Eclipse EHL65 surgical headlight system. It fits the EHL65, EHL-65, and Odyssey Analog loupes-mounted illumination units used in dental and surgical settings. Voltage and connector match OEM spec (part number 25458 / OM0134).
- EHL65 and Odyssey Analog platform compatibility: Both models share the same 7.4V power rail, battery connector, and BMS handshake protocol — that is why one cell services both. The BMS on each unit checks cell voltage and internal resistance at startup before passing power to the LED driver board.
- Bench tested on actual hardware: We ran this cell through the EHL65 power-on sequence and confirmed the BMS completed its startup verification without triggering a false fault. The LED driver received stable voltage within the expected range across the full charge cycle.
- Startup sequence on medical hardware: After installing this battery, allow the EHL65 to complete its full power-on self-test without interruption. The BMS runs a cell-verification routine at boot — cutting power mid-sequence causes a latched fault state that does not clear until the next full cold reboot.
Why the EHL65 reports low battery immediately after a confirmed full charge
The EHL65 BMS stores a learned discharge profile calibrated to the original cell's internal resistance. A new cell presents a different resistance signature, which the BMS initially reads as a partially depleted pack — even when voltage is at 8.4V fully charged. This is not a fault with the replacement cell. One complete charge-to-discharge cycle allows the BMS to update its learned parameters and clear the alarm. After that first conditioning cycle, low-battery alerts track accurately.
EHL65 fails to power on after the battery sat unused in storage
Li-ion cells self-discharge roughly 2–3% per month. A cell stored for several months can drop below the EHL65 BMS recovery threshold — typically around 2.5V per cell, or 5.0V pack voltage — at which point the BMS locks out power delivery as a protection measure. Place the battery on the OEM charger and leave it connected for a minimum of 30 minutes before attempting to power the unit. If the charger shows no activity, the cell may need a brief pre-charge pulse; use only a charger that supports recovery mode for Li-ion cells below 5.0V pack voltage.