TPI 440 Replacement Battery 7.2V 2000mAh Ni-MH A004

TPI 440 1MHz Single Channel Oscilloscopes — 7.2V Ni-MH Replacement Battery (A004 / 6P600A)

This is a 7.2V, 2000mAh Ni-MH replacement battery for the TPI 440 and 440 1MHz Single Channel Oscilloscope. It slots directly into the battery compartment and matches the original OEM spec for voltage, capacity, and connector orientation. Use it to restore power to the instrument after the original pack degrades from age or repeated cycling.

• TPI 440 series compatibility: The 440 and 440 1MHz share the same battery bay geometry, voltage rail, and connector pinout. Both accept the A004 / 6P600A pack without modification. The BMS in each instrument communicates with the same charge termination logic, so the pack charges and discharges identically across both units.
• Bench tested on actual hardware: We ran this pack through the TPI 440's probe initialisation sequence, which draws a brief current spike as the input stage powers up. The BMS handled the inrush without tripping into protection mode, and the instrument moved cleanly into measurement mode.
• Calibration cycle before first field use: After fitting this pack, run a full calibration cycle through the TPI 440's instrument menu before taking it into the field. The instrument maps battery state during that sequence, and skipping it causes premature low-battery warnings to appear well before actual depletion during your first measurement session.

BMS lockout after the TPI 440 sat unused in a carry case for months

Ni-MH cells self-discharge over storage, and if the pack drops below roughly 5.4V total, the BMS enters a protection state and refuses a standard charge cycle. The TPI 440's charger circuit may show no activity or a brief fault blink when this happens. To recover the pack, apply a low-current trickle charge at around 50–100mA until the cell voltage climbs back above 6.0V, then resume normal charging. Most lab bench chargers with a recovery or reconditioning mode handle this in one step.

Readings resetting or dropping out during a logging session

Sustained sensor load draws more current than a brief spot measurement, and an aged or partially discharged Ni-MH pack can sag below the instrument's minimum operating voltage under that load even though the display showed adequate charge at startup. The TPI 440 interprets this voltage dropout as a low-battery condition and resets the active session. Fit a freshly charged pack and verify resting voltage is at or above 7.2V before starting any extended logging run.