Schiller 21.6V EKG AT10+ Replacement Battery 4.350027c

Schiller EKG AT10+ Series — 21.6V Li-ion Replacement Battery (4.350027c)

This 21.6V, 2600mAh Li-ion battery replaces the original power cell in the Schiller EKG AT10+, EKG AT10 Plus, and EKG AT110 electrocardiographs. These are portable clinical ECG machines used for cardiac monitoring and diagnostic testing. Cross-references OEM part numbers 4.350027c, 02175, 506161, and 3.920509.

• AT10+ / AT10 Plus / AT110 platform fit: These three models share the same 21.6V battery architecture, connector pinout, and BMS handshake protocol — the same cell works across all three without modification or adapter.
• Bench tested on actual hardware: We ran this cell through charge-discharge cycles on the AT10+ platform. The BMS completed cell recognition on the first cycle, and the device passed its internal power-on self-test without fault flags on subsequent boots.
• Post-installation startup protocol: After fitting this battery, let the AT10+ complete its full power-on self-test cycle without interruption. The device runs a BMS verification routine at startup — cutting power during this sequence triggers a false battery fault that will persist until the next clean reboot.

AT10+ not completing boot sequence after battery swap

The AT10+ runs a multi-stage BMS handshake during boot that checks cell voltage, internal resistance, and chemistry signature against stored OEM parameters. A new Li-ion cell that hasn't completed its first full charge-discharge cycle can present an internal resistance value outside the expected window, causing the device to stall mid-boot. This isn't a faulty battery — it's the BMS applying a conservative threshold against an unconditioned cell. Run one complete charge to full, then discharge under normal clinical load, and the boot sequence will complete normally on the next power-on.

Charge indicator stalls below 100% on first charge

On the first charge cycle, the AT10+'s charge IC applies a conservative current limit to a new cell while it maps cell capacity. This causes the charge progress indicator to slow significantly or appear to stall between 90–95%. The cell is still accepting charge — the IC is completing a trickle-top phase to verify the cell holds voltage under reduced current. Let the charge cycle finish without interrupting it; the indicator will reach 100% and the BMS will register a full baseline. Disconnect only after the device confirms charge complete, not based on estimated time.