Nihon Kohden OLV-2700 Monitor Replacement Battery 7.2V

Nihon Kohden OLV-2700 / OLG-2800 Monitor — 7.2V Ni-MH Replacement Battery (X072)

This is a 7.2V, 2500mAh Ni-MH replacement battery for the Nihon Kohden OLV-2700 and OLG-2800 patient monitors. It replaces OEM part numbers X072 and YS-085P6. These monitors are used in clinical settings to display continuous vital signs data, and battery integrity directly affects their ability to operate during power transitions or transport.

• OLV-2700 and OLG-2800 compatibility: Both monitors share the same battery bay format, connector pinout, and BMS handshake protocol. The X072 cell spec — 7.2V Ni-MH at 2500mAh — applies to both units without modification or adapter.
• Bench tested on actual hardware: We ran this cell through full charge-discharge cycles on bench equipment and logged the BMS charge acceptance and cutoff behaviour. The protection circuit responded within spec on both overcharge and low-voltage cutoff thresholds.
• Post-swap self-test protocol: After installing this battery, let the OLV-2700 or OLG-2800 complete its full power-on self-test without interruption. These monitors run a BMS verification sequence at startup — cutting power during that window causes a false battery fault that latches until the next clean reboot.

Why the OLV-2700 flags a battery fault after a confirmed full charge

The OLV-2700 BMS stores an internal capacity model from the previous cell. When a new Ni-MH cell goes in, the monitor's charge IC applies a conservative acceptance threshold until it has logged one complete charge-discharge cycle. Until that cycle completes, the BMS has no calibrated baseline for the new cell's actual capacity curve. This is not a fault with the replacement — it is the monitor recalibrating. Run one full charge-discharge cycle before clinical deployment to clear the mismatch.

Monitor will not power on after replacement cell sat in storage

Ni-MH cells self-discharge during storage, and if voltage drops far enough, the OLV-2700's BMS enters a protection state that blocks normal startup. The monitor sees the low resting voltage as a potentially damaged or shorted cell and refuses to pass current to the load circuit. Connect the monitor to mains power first — this lets the charge IC deliver a low-rate recovery charge before the BMS re-evaluates the cell. Once resting voltage recovers above approximately 6.0V, the monitor will complete its boot sequence normally.