Owon PDS Oscilloscope Replacement Battery 7.4V 7800mAh 540-337

Owon PDS5022 / PDS602 / HC-PDS Series — 7.4V Li-ion Replacement Battery (540-337)

This 7.4V 7800mAh (57.72Wh) lithium-ion battery replaces the original 540-337 pack in Owon PDS series portable digital storage oscilloscopes. It fits the PDS5022, PDS602, and HC-PDS units along with other PDS platform models. The cell and BMS are matched to the voltage rail and communication protocol these oscilloscopes expect at power-on.

• PDS platform compatibility: The PDS5022, PDS602, and HC-PDS share the same 7.4V battery bay, connector pinout, and BMS handshake. One pack covers the range because Owon kept the power architecture consistent across the series — the oscilloscope firmware reads state-of-charge over the same data line on all these units.
• Bench tested on actual hardware: We ran this pack through power-on initialisation, probe channel activation, and sustained waveform capture across both channels simultaneously. The BMS held the voltage rail steady during the current spike at probe power-up and did not trip into protection mode.
• Post-install calibration step: After fitting this pack, run a full calibration cycle through the PDS instrument menu before field use. The oscilloscope maps battery state-of-charge during that sequence — skipping it causes the low-battery indicator to trigger early on the first measurement session, even with a fully charged pack.

BMS cutoff when both probe channels initialise simultaneously on the PDS5022

When you power on a two-channel PDS oscilloscope and both probe inputs initialise at the same time, there is a brief current spike as each channel's input amplifier and coupling circuit energises. On a degraded original battery, the internal resistance is high enough that this spike causes a voltage sag that crosses the BMS under-voltage threshold — triggering an immediate shutdown. This pack's cells have lower internal resistance, so the voltage rail stays above the cutoff point during that initialisation window. If you are still seeing shutdowns at power-on, check that the battery contacts in the bay are clean and making full contact before assuming a battery fault.

Waveform display resets mid-capture during a logging session

This symptom — the screen blanks and the oscilloscope restarts while a capture is running — points to a momentary voltage dropout under sustained load rather than a full BMS trip. It happens when the cell capacity has faded to the point where it cannot maintain 7.4V output under the combined draw of the display backlight, active sampling, and storage write cycles. The oscilloscope firmware interprets the dropout as a power fault and performs a soft reset. Confirm the replacement pack is reading above 7.2V under load using the battery status screen in the PDS menu before logging a long capture session.