Burdick 5834 16.8V Ni-CD Replacement Battery 700mAh 4i EKG

Burdick 4i EKG / 400 / 850 Series — 16.8V Ni-CD Replacement Battery (5834)

This is a 16.8V, 700mAh Ni-CD replacement battery for the Burdick 4i EKG and compatible models including the 400 and 850 series. It replaces OEM part numbers 5834, 120292, 862988, and several other cross-references used across the Burdick portable electrocardiograph range. The battery slots directly into the device housing and restores power for clinical cardiac recording when the original cell has degraded.

• 4i EKG, 400, and 850 compatibility: These Burdick models share the same 16.8V power rail and battery bay dimensions. The BMS on each unit expects the same cell configuration and connector pinout, which is why a single part number covers the full range. Swapping between these models requires no adapter or modification.
• Bench tested on actual hardware: We cycled this battery through charge and discharge on the Burdick platform and confirmed the BMS handshake completes without fault codes. Cell voltage under load held within the expected range across the first five cycles, with capacity stabilising by cycle three.
• Post-installation self-test on medical hardware: After installing this battery, let the Burdick unit complete its full power-on self-test without interruption. Medical-grade EKG devices run a BMS verification sequence at startup. Cutting power during that sequence stores a false battery fault that will persist until the next clean reboot — it is not a cell defect.

Why the Burdick 4i EKG triggers a low battery alarm on a freshly charged new cell

The Burdick BMS uses a stored charge profile calibrated to the original OEM cell's voltage curve. A new Ni-CD cell at first charge sits at a slightly different voltage point than a conditioned cell, and the BMS interprets that gap as insufficient capacity. The alarm clears after one complete charge-discharge cycle, which lets the charge IC re-map the cell's actual curve. Run the unit through a full cycle before any clinical use — the alarm is a calibration artefact, not a fault.

Burdick unit will not power on after the replacement battery sat in storage

Ni-CD cells self-discharge during storage, and if the cell voltage has dropped below approximately 12V, the Burdick BMS will not initiate a normal boot — it treats the pack as deeply discharged and blocks startup as a protection measure. Connect the unit to mains power and leave it on charge for a full cycle before attempting to power on. Most units recover once the cell climbs back above the BMS recovery threshold. If the charger indicator does not respond within 30 minutes of connection, disconnect and reconnect to trigger a fresh charge-initiation handshake.