About this replacement
Edan MI-807 / Acclarix A8 — 14.8V Li-ion Replacement Battery (TWSLB-013)
This is a 14.8V, 7800mAh (115.44Wh) lithium-ion replacement battery for the Edan MI-807 Ultrasound system and Acclarix A8 portable ultrasound units. Both devices share the TWSLB-013 form factor, connector pinout, and BMS handshake protocol. Capacity figures come from product data — not manufacturer marketing sheets.
- MI-807 and Acclarix A8 compatibility: Both units run the same 14.8V four-cell series configuration and share identical BMS communication lines. The TWSLB-013 connector carries both power and data — the device reads cell state from the battery's onboard fuel gauge, not a simple voltage sense pin.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on a 14.8V load bank, monitoring BMS handshake acknowledgement and cell balancing behaviour across all four groups. The protection circuit tripped correctly at low-voltage cutoff and recovered cleanly on reconnect.
- Post-swap startup protocol: After installing this battery, allow the MI-807 to complete its full power-on self-test without interruption. The device runs a BMS verification sequence at boot — cutting power mid-cycle causes a false battery fault flag that persists until the next clean reboot.
Why the MI-807 shows a battery fault after a fresh install
The MI-807 uses a smart BMS that stores a learned capacity baseline. When a new cell arrives, the device's charge IC has no prior cycle data to reference and applies conservative thresholds. This often triggers a fault flag on the first one or two boots — not a defective cell. Run one complete charge-discharge cycle before treating any fault indicator as a hardware failure. The BMS learn cycle clears the flag automatically once it has a full reference cycle recorded.
Charge indicator not reaching 100% on the first charge
On a new cell, the MI-807's charge IC applies a reduced current ceiling during the first charge session — this is normal cell conditioning behaviour, not a charger fault. The indicator may plateau at 95–98% and stay there. Allow the charge cycle to terminate naturally rather than interrupting it. On the second charge, the IC relaxes its ceiling and the indicator will reach 100% at the correct 16.8V termination voltage.