Panasonic VW-VBX090 WA20 Compatible Battery 3.7V 770mAh

Panasonic WA20 / HX-WA20 Series — 3.7V Li-ion Replacement Battery (VW-VBX090)

This is a 3.7V 770mAh lithium-ion cell replacing the Panasonic OEM part VW-VBX090. It fits the WA20, WA2, HX-WA20, HX-WA2, and related compact camera models in the HX-WA series. Voltage and capacity match the original spec so the camera body powers on and displays battery status as expected.

• HX-WA series compatibility: The WA20, WA2, HX-WA20, and HX-WA2 share the same battery bay dimensions, 3.7V rail, and VW-VBX090 connector footprint. The BMS in each body reads the same charge termination signals, so one cell covers the full group without modification.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge passes on camera hardware. The BMS accepted the cell without error flags, and charge termination triggered correctly at the top of the voltage curve.
• First-use charge cycle on WA-series bodies: Run the first charge inside the camera body or OEM charger — not a third-party USB adapter. The WA-series BMS maps battery-remaining percentage against a discharge profile it builds on the first full cycle. Skipping this step can cause the indicator to read inaccurately for the life of the cell.

Why the HX-WA20 shows a dead battery indicator on a partially charged replacement cell

The HX-WA20 maps its battery indicator to a fixed voltage-threshold table calibrated against the OEM cell's discharge curve. A new replacement cell can sit at 3.6V and still show one bar or a blinking low-battery warning if the BMS hasn't yet profiled it. This is a display mapping issue, not a cell fault. Run one complete charge cycle — from flat to full charge termination — inside the camera body, and the indicator will realign to the actual state of charge.

Battery percentage jumping erratically during video recording on the WA20

Sustained video recording on the WA20 pulls harder on the cell than still shooting — sensor readout, continuous autofocus, and image stabilisation all draw simultaneously. If the replacement cell hasn't completed a full charge cycle, the BMS voltage-to-percentage lookup can jump because the discharge profile isn't yet settled. A secondary cause is a loose contact in the battery bay; check that the cell seats fully and the gold contacts are clean. Complete one full charge-discharge cycle in-camera, then verify the bay contacts, and erratic percentage readings typically stop.