Palm Tungsten E Replacement Battery UP383562A 3.7V 1250mAh

Palm Tungsten E — 3.7V Li-Polymer Replacement Battery (UP383562A A6)

This 3.7V, 1250mAh lithium-polymer cell replaces the original battery in the Palm Tungsten E PDA. It fits the Tungsten E only — not the Tungsten E2 or other Palm handhelds that use different cell sizes and connector pinouts. Capacity is sourced from the product specification: 1250mAh / 4.63Wh.

• Tungsten E platform fit: The Tungsten E uses a 60.20 × 36.50 × 5.00mm Li-Polymer cell with a specific three-wire connector. The BMS on this device monitors cell voltage directly — a mismatched cell geometry causes connector stress and incomplete seating, which the BMS reads as an open circuit.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on a Tungsten E unit. The BMS accepted the cell without fault flags, charged to full 4.2V without cutoff errors, and held voltage steady through the full discharge curve.
• Sync before you swap: The Tungsten E holds calendar entries, contacts, and memo data in volatile SRAM. That RAM loses its contents the moment main battery power drops to zero. HotSync to your desktop before removing the old cell — not after.

Why the Tungsten E goes blank and won't boot after a battery swap

The Tungsten E boot sequence requires the cell to deliver at least 3.5V before the processor initialises. A new Li-Polymer cell shipped in storage state often sits at 3.2–3.3V — below that threshold. The device appears dead even though the battery and hardware are both functional. Connect to the Palm charging cradle or USB cable and charge for at least 30 minutes before attempting a first boot.

Tungsten E showing full charge but dying faster than the original battery did

This usually means the fuel gauge — a simple voltage-to-percentage lookup table stored in the OS — hasn't recalibrated to the new cell's actual discharge curve. The device reports 100% based on voltage alone, but cuts off earlier than expected. Run two full charge-to-cutoff cycles without interruption. After the second cycle, the displayed percentage will track the real remaining capacity accurately.