About this replacement
Ideal SignalTEK CT / NaviTEK II Series — 7.2V Ni-MH Replacement Battery (150053 / 150401)
This is a 7.2V, 2000mAh Ni-MH replacement battery for Ideal cable testers including the SignalTEK CT, SignalTEK II FO, NaviTEK II, and LanXPLORER. OEM part numbers 150053 and 150401 both cross-reference to this pack. It restores field testing capability when the original cell can no longer hold a working charge across a full testing session.
- SignalTEK and NaviTEK platform fit: These models share the same 7.2V two-cell Ni-MH stack, matching connector footprint, and BMS handshake protocol — which is why a single replacement pack covers the full line. Voltage rail and physical form factor are identical across all listed units.
- Bench tested on actual hardware: We cycled this pack through the SignalTEK CT's probe initialisation sequence, which draws a short current spike at power-up. The BMS held through repeated cold starts without nuisance trips, and cell balance remained stable across a full discharge cycle.
- Post-install calibration on Ni-MH instruments: After fitting this pack, run a full calibration cycle through the instrument menu before taking it to site. The SignalTEK family maps battery state during calibration — skip this step and the low-battery indicator will trigger early on your first measurement session, even with a full charge.
SignalTEK CT shutting down mid-test after sitting unused for weeks
Ni-MH cells self-discharge faster than Li-ion — a pack left in a carry case for four to six weeks can drop below the BMS recovery threshold. When the instrument attempts to power a probe module from a deeply discharged pack, the BMS trips before the display even stabilises. The cell isn't dead; it just needs a slow pre-charge to bring voltage back above 6.0V before a normal charge cycle can complete. Place the pack on charge for a full uninterrupted cycle rather than a short top-up, and check that terminal voltage reads at least 7.0V before reinstalling.
Cable ID readings resetting or dropping out during a logging session
Sustained sensor load during a multi-cable logging run draws more current than a single continuity test — voltage can sag enough mid-session to trigger a brief BMS cutoff and reset the active log. This isn't a faulty unit; it's an aged cell with high internal resistance failing to hold voltage under continuous draw. A new pack with fresh cells maintains voltage above the 6.5V dropout threshold that the SignalTEK CT uses to protect its measurement circuit. If dropouts persist after fitting a new battery, check that the pack contacts are clean and seating fully in the bay.