About this replacement
Cardioline ECG Delta 1 Series — 24V Ni-MH Replacement Battery (120222)
This 24V 2000mAh Ni-MH battery replaces part number 120222 in the Cardioline ECG Delta 1, Delta 1+, Delta 3+, and related portable electrocardiograph units. It is a direct cell replacement for clinical environments where the original pack has degraded or failed capacity. Voltage and chemistry match the OEM specification exactly.
- ECG Delta series compatibility: The Delta 1, Delta 1+, and Delta 3+ share the same 24V battery architecture and connector format. Each unit runs the same BMS handshake on startup, so the same pack works across the series without modification.
- Bench tested on actual hardware: We cycled this pack through charge and discharge on the Delta 1 platform. The BMS accepted the new cell, completed its verification pass, and reported correct state-of-charge on the device display after the first full cycle.
- Post-swap self-test cycle: After fitting this battery, allow the ECG unit to complete its full power-on self-test without cutting power. The Delta series BMS runs a chemistry verification at boot — interrupting it locks in a false battery fault that persists until the next complete reboot.
Low battery alarm triggering immediately after a confirmed full charge
The Delta 1 BMS uses a voltage threshold calibrated to an aged OEM cell profile. A new Ni-MH cell presents a slightly different internal resistance signature during the first few cycles, which the BMS can misread as a low-state pack. This triggers the low battery alarm even when the cell is fully charged. Run one complete charge-discharge cycle before clinical use — after that cycle the BMS recalibrates its threshold to the new cell and the alarm clears.
Device will not power on after the replacement battery sat in storage
Ni-MH cells self-discharge during storage. If the pack voltage drops below approximately 18V, the Delta 1 BMS enters a lockout state and refuses to power the unit to protect the cell. Placing a deeply discharged pack in the device and pressing power produces nothing — no boot, no alarm. Connect the charger first and leave it for a minimum of two hours before attempting to power on; the BMS recovery routine requires sustained trickle current to exit lockout and resume normal operation.