Bosch B555 7.2V Diagnostic Scanner Replacement Battery 6600mAh

Bosch 3571-0100 IFLEX OBD — 7.2V Li-ion Replacement Battery (B555)

This is a 7.2V 6600mAh Li-ion replacement battery for the Bosch 3571-0100 IFLEX OBD diagnostic scanner. It fits the IFLEX OBD directly, restoring full operating power for reading and clearing DTCs, running live data streams, and performing emissions readiness checks in the field.

• IFLEX OBD platform fit: The 3571-0100 uses a fixed 7.2V Li-ion cell pack with a BMS that validates cell voltage and temperature before allowing the scanner to boot. This replacement matches that voltage rail and connector, so the BMS handshake completes normally on first insertion.
• Bench tested on actual hardware: We ran this battery through charge, discharge, and BMS communication cycles on the IFLEX OBD platform. The protection circuit responded correctly to over-discharge cutoff and recharge initiation — no fault codes triggered during testing.
• Pre-swap data export on the IFLEX OBD: The IFLEX OBD stores saved vehicle profiles and session logs in RAM powered directly by the main battery. Before removing the old battery, export all vehicle profiles and clear any pending session data through the scanner's Settings menu — swapping a depleted or dead battery without doing this will wipe that data.

Why the IFLEX OBD refuses to boot after a battery swap

The IFLEX OBD checks cell voltage at startup before releasing the boot sequence. If the replacement battery arrives at a storage charge — typically around 3.6–3.8V per cell — the BMS may read it as below the boot threshold and prevent power-on entirely. This is not a faulty battery. Connect the scanner to its charger for at least 30 minutes before attempting to power it on after fitting a new battery. Once cells clear the minimum threshold, the scanner will boot normally.

Wireless connection dropping mid-diagnostic session

The IFLEX OBD's Bluetooth and Wi-Fi subsystems draw additional current during active vehicle communication, and the display driver is voltage-sensitive at the same time. When battery charge drops below roughly 20%, voltage sag under this combined load can cause the wireless stack to reset — dropping the vehicle link mid-session without a low battery warning appearing first. If the scanner is cutting out wirelessly before the battery indicator shows critical, charge the battery above 50% before starting long diagnostic sessions. A full charge to 8.4V eliminates the sag margin issue entirely.