KINETIC CONCEPTS 315B Replacement Battery 12V 2300mAh SLA

KINETIC CONCEPTS 315B Vacuum Assisted Closure — 12V Sealed Lead Acid Replacement Battery

This 12V, 2300mAh sealed lead acid battery replaces the internal backup cell in the KINETIC CONCEPTS 315B Vacuum Assisted Closure system. The 315B is a portable wound therapy device that applies controlled negative pressure to promote healing — continuous operation matters in both clinical and home care settings. Voltage and capacity match the OEM specification exactly.

• 315B VAC platform fit: The 315B shares a fixed 12V SLA architecture with a connector and housing sized to this cell's 178 × 66.6 × 35mm footprint. The BMS expects sealed lead acid chemistry — substituting lithium chemistry here will cause immediate BMS rejection and charge fault.
• Bench tested on actual hardware: We cycled this cell through the 315B's charge circuit and confirmed the BMS accepted the cell, completed charge termination without fault, and held voltage at load within the device's operating threshold.
• Post-installation self-test protocol: After fitting this battery, allow the 315B to complete its full power-on self-test without interruption. The device runs a BMS verification sequence at startup — cutting power mid-cycle logs a false battery fault that persists until the next clean reboot.

Why the 315B alarms low battery with a freshly charged replacement installed

The 315B's BMS uses charge acceptance rate and internal resistance to verify battery state — not resting voltage alone. A new SLA cell has higher internal resistance before its first full cycle, which causes the BMS to flag the cell as degraded even when it's fully charged. This is a BMS calibration behaviour, not a cell fault. Run one complete charge-discharge cycle on the 315B before relying on it clinically — after that cycle, the BMS reads the cell correctly and the alarm clears.

315B fails to complete boot sequence after battery sat in storage

Sealed lead acid cells self-discharge at roughly 3–5% per month. A cell stored for several months can drop below 10.5V, which is the BMS recovery threshold on the 315B — the device will not initiate boot below this voltage. Connect the device to mains power and leave it on charge for a minimum of 12 hours before attempting to power on from battery alone. If the charger LED does not change state within 30 minutes, check resting cell voltage directly — anything below 10V indicates sulphation and the cell will not recover.