About this replacement
HP Jornada 920 / 928 — 3.7V Li-Polymer Replacement Battery (F2937A)
This is a 3.7V, 950mAh Li-Polymer battery for the HP Jornada 920 and Jornada 928 Pocket PC handhelds. It replaces OEM part number F2937A, which is the original cell used in both models. If your Jornada no longer holds a charge or won't power on at all, this battery is the direct swap.
- Jornada 920 and 928 compatibility: Both models share the same battery bay dimensions, connector pinout, and 3.7V power rail. The BMS communication protocol is also identical across the two, so one cell covers both without modification.
- Bench tested on actual hardware: We ran the F2937A replacement through charge and discharge cycles on a Jornada unit. The BMS accepted the cell without fault codes, held charge across the full cycle, and delivered a stable output voltage throughout discharge.
- RAM data protection before swap: Perform a full ActiveSync data sync to a host PC before removing the battery. The Jornada 920 stores open files, contacts, and application state in volatile SRAM powered directly by the main battery. Pulling the cell without syncing wipes that data permanently.
Why the Jornada 920 loses all data after a battery replacement
The Jornada 920 uses SRAM as its primary storage for active data, and that SRAM requires continuous power to retain its contents. Unlike flash-based storage, SRAM loses everything the moment voltage drops to zero — which happens during a battery swap. There is no background retention circuit on this model that bridges the gap during cell removal. Sync to a PC via ActiveSync before every battery change, then restore from backup after fitting the new cell.
Jornada 928 won't boot after fitting a new battery
A freshly shipped Li-Polymer cell typically arrives at a storage charge of around 3.0–3.2V. The Jornada's boot sequence demands a minimum voltage threshold before the processor will initialise, and a partially discharged cell can fall short of that threshold. The device may show nothing on screen or display a low-battery icon immediately. Connect to the original HP charger and allow the cell to reach at least 3.6V before attempting to power on.