About this replacement
AAXA P1 Pico Projector — 3.7V Li-Polymer Replacement Battery (KP250-03)
This 3.7V, 1700mAh Li-Polymer cell replaces the original KP250-03 battery in the AAXA P1 Pico Projector. It restores the projector's ability to run untethered — away from a wall outlet — for presentations, classroom use, or outdoor viewing. Capacity matches the factory specification at 1700mAh (6.29Wh).
- P1 Pico Projector fit: The P1 uses a single-cell Li-Polymer pack at 3.7V nominal. The KP250-03 format is specific to this chassis — the cell dimensions (49.47 × 36.55 × 8.97mm) and connector position must match exactly for the battery door to close and the BMS handshake to complete.
- Bench tested on actual hardware: We cycled this cell through the P1's internal charge circuit and confirmed the BMS accepted the cell, balanced charge terminated correctly, and the projector powered on without a fault flag on the status LED.
- Lamp draw management on battery: Set the P1 to eco or low-brightness mode when running on battery. Full lamp brightness pulls 30–40% more current than eco mode. The projector's power rail will sag under that load faster, and the lamp controller may cut the image before the battery indicator reaches empty.
Why the P1 shuts off mid-presentation before the battery reads empty
The P1's lamp controller requires a minimum voltage threshold — typically around 3.4V under load — to sustain the LED or lamp driver. A Li-Polymer cell's terminal voltage drops under current draw, so the projector can hit that cutoff while the open-circuit voltage still reads "charged." This is more pronounced with an aged or partially degraded cell, but it also happens with a new cell at full lamp brightness. The fix is straightforward: reduce lamp brightness in the projector's settings, which lowers current draw and keeps the terminal voltage above the lamp controller's cutoff point for longer.
P1 not charging after battery has been fully discharged
If the P1 sits unused for several weeks with a depleted cell, the Li-Polymer battery can drop below 2.5V — the threshold at which most BMS circuits refuse a standard charge cycle as a safety measure. The projector's internal charger may show no charging activity or an error state. To recover the cell, connect the projector to power and leave it for 20–30 minutes without powering it on — some charger ICs include a trickle pre-charge stage that slowly brings the cell back above 3.0V before switching to normal CC/CV charging. If the cell does not recover above 3.0V after an extended trickle period, the cell has over-discharged beyond recovery and replacement is the correct next step.