About this replacement
Palm M100 / M105 — 2.4V Ni-MH Replacement Battery
This is a 2.4V 750mAh Ni-MH replacement battery for the Palm M100 and M105 handheld PDAs. It fits directly into the original battery compartment and restores power to devices that no longer hold a charge after years of use. Voltage and cell format match the original Palm specification.
- M100 and M105 compatibility: Both models share the same battery bay dimensions and 2.4V power rail. The connector orientation and cell pack geometry are identical across the two, so one replacement covers both without modification.
- Bench tested on actual hardware: We cycled this battery through charge and discharge on an M100 unit. The cell accepted a full charge without thermal event, and the Palm OS boot sequence completed normally at rated voltage.
- Sync before you swap: The Palm M100 stores all contacts, calendar entries, and notes in SRAM powered directly by the main battery. Pull the battery without syncing first and that data is gone. Run a HotSync to your desktop before opening the battery cover — every time.
Why the M100 loses all data when the battery is replaced
The Palm M100 has no flash storage for user data. Everything — contacts, memos, calendar events, app state — lives in volatile SRAM. That RAM needs continuous battery voltage to retain its contents. The moment voltage drops to zero during a swap, the memory clears completely. This is not a fault with the new battery; it is how the M100 architecture works. A HotSync before the swap is the only way to protect that data.
Palm M100 won't boot after installing a new battery
A freshly shipped Ni-MH cell may arrive partially discharged. If the resting voltage is too low, the M100 boot sequence stalls before the Palm OS splash screen appears. This is a voltage floor issue, not a faulty battery or a faulty device. Connect the M100 to its charging cradle or cable and let the new cell charge for at least two hours before attempting to power on. Once voltage climbs above approximately 2.2V, the unit will boot normally.