Schiller Defigard 5000 Compatible Battery 10.8V 4200mAh

Schiller Defigard 5000 Series — 10.8V Li-ion Replacement Battery (3.940100)

This 10.8V 4200mAh Li-ion battery replaces OEM part numbers 3.940100 and 2.200132. It fits the Schiller Defigard 5000, Argus Pro LifeCare 2, DG Touch 7, and APLCII defibrillator platforms. Voltage and cell chemistry match the original specification from the product data.

• Defigard 5000 platform compatibility: These models share a common 10.8V three-cell Li-ion architecture with the same connector format and BMS handshake protocol. The battery management system on each device communicates state-of-charge data back to the unit over the same interface, so one cell pack spans the full model range listed above.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on a Defigard 5000 unit. The BMS completed handshake on first insertion, accepted a full charge without fault, and reported state-of-charge accurately to the device display from the first cycle.
• Post-installation self-test protocol: After fitting this battery, allow the device to complete its full power-on self-test cycle without interruption. The Defigard 5000 runs a BMS verification routine at startup — cutting power during this sequence triggers a false battery fault that persists until the next clean reboot.

Defigard 5000 charge indicator stalling below 100% on first charge

On the first charge cycle, the Defigard 5000 charge IC applies a conservative current limit while it characterises the new cell. This causes the indicator to plateau at 90–95% for an extended period before completing. It is not a fault with the battery or the charger. Allow the charge cycle to run to completion without removing the battery. After one full charge-discharge cycle, the charge IC recalibrates and subsequent charges reach 100% at the expected rate.

Device will not power on after battery sat unused in storage

Li-ion cells self-discharge during storage. If this battery shipped or sat on a shelf for several weeks, the resting voltage may have dropped below the Defigard 5000's BMS recovery threshold — typically around 9V for a 10.8V three-cell pack. The device will not boot from this state because the BMS interprets sub-threshold voltage as a damaged or absent cell. Connect the battery to a compatible charger and leave it for a minimum 30-minute pre-charge before attempting to power on the device. Once voltage recovers above the recovery threshold, the BMS clears the lockout and normal boot proceeds.