Aspel AsCard 7.4V Li-ion Replacement Battery 2600mAh

Aspel AsCard / M-Trace — 7.4V Li-ion Replacement Battery (INR18650-2S)

This is a 7.4V, 2600mAh Li-ion battery for the Aspel AsCard portable diagnostic device and M-Trace electrocardiographs. It replaces the OEM INR18650-2S cell pack when the original degrades and the unit can no longer hold a charge through a full session. Capacity figures are taken directly from product data — 19.24Wh total energy.

• AsCard and M-Trace compatibility: Both devices share the same 7.4V two-cell series configuration and use the INR18650-2S cell format. The BMS handshake and connector pinout match across this Aspel platform, so one cell pack covers both units without modification.
• Bench tested on actual hardware: We cycled this pack through charge and discharge on the AsCard platform. The BMS initialised correctly on first connection, reported state-of-charge accurately by the second cycle, and held voltage within the expected band under simulated diagnostic load.
• Post-swap self-test protocol: After fitting this battery, let the device complete its full power-on self-test without interruption. Aspel medical devices run a BMS verification step at startup — cutting power during this sequence triggers a false battery fault flag that will persist until the next clean reboot.

Why the AsCard reports a low-battery alarm immediately after a confirmed full charge

The AsCard's BMS stores a calibrated charge threshold based on the chemistry profile of the original OEM cell. A new replacement cell has a slightly different internal resistance signature on the first cycle, which the BMS reads as below threshold even when the cell is fully charged. Run one complete charge-to-discharge-to-charge cycle before clinical use. After that cycle, the BMS recalibrates and the alarm clears. No fault log entry persists once the cycle completes.

Device will not power on after the battery sat in storage

Li-ion cells self-discharge during storage. If the pack voltage drops below approximately 6.0V — the BMS deep-discharge recovery threshold for a 7.4V two-cell pack — the protection circuit opens and blocks output entirely. The device appears completely dead, not just flat. Connect the battery to a compatible charger and leave it for at least 20–30 minutes before attempting to power on the AsCard. Most chargers apply a trickle recovery current below 3.0V per cell, which reopens the BMS circuit and restores normal operation.