Toshiba PDR-BT1 Allegretto M70 3.7V Replacement Battery

Toshiba Allegretto M70 / PDR-M70 — 3.7V Li-ion Replacement Battery (PDR-BT1)

This is a 3.7V, 1400mAh Li-ion replacement cell for the Toshiba Allegretto M70 and PDR-M series digital cameras. It fits the PDR-M4, PDR-M5, and PDR-M70 alongside the Allegretto M70. OEM part numbers PDR-BT1, PDR-BT2, and PDR-BT2A all cross to this cell.

• PDR-M and Allegretto M70 compatibility: These models share the same battery bay dimensions and 3.7V single-cell architecture. The connector orientation and BMS communication protocol are identical across the PDR-M4, M5, M70, and Allegretto M70, so one cell covers the full range.
• Bench tested on actual hardware: We cycled this cell through the PDR-M70 body. The BMS accepted the cell on first install, charge termination triggered cleanly at 4.2V, and the battery indicator tracked accurately through the discharge curve.
• First charge via camera body: Charge this cell in the camera body rather than a universal charger on first use. The Toshiba PDR-M series BMS calibrates its remaining-capacity display during an in-body charge cycle — skipping this step can cause the indicator to read full immediately then drop sharply mid-shoot.

Battery percentage jumping erratically on the PDR-M70 display

The PDR-M series maps voltage thresholds from the original Toshiba cell's discharge curve to its battery indicator. A replacement cell with a slightly different discharge profile can cause the indicator to jump — showing 80% one moment and 20% the next without warning. This is not a cell fault. Run two full charge and discharge cycles in the camera body and the BMS re-maps its thresholds to the new cell's curve. After that, the display stabilises and tracks consistently.

Flash not fully recycling between shots on the Allegretto M70

Flash recycle time lengthens when the cell can no longer supply the brief high-current pulse the capacitor needs to recharge. On the Allegretto M70, this shows up as a noticeably longer wait between flashes — or the flash failing to fire at all — even when the battery indicator still shows charge remaining. The cause is voltage sag under load, not low state of charge. If a fresh replacement cell shows this behaviour, check that the battery contacts in the bay are clean and making full contact. Press the cell firmly into the bay until it clicks, then retest.