About this replacement
Tektronix TFS3031 / 965 Series — 14.4V Ni-MH Replacement Battery (LP43SC12S1P)
This is a 14.4V 3000mAh Ni-MH battery for the Tektronix TFS3031, 965, and DSP 78-8097-5058-7 field survey instruments. It replaces OEM part numbers LP43SC12S1P and 146-0112-00. The pack restores untethered operation during on-site telecommunications and network testing.
- TFS3031 and 965 platform fit: These models share the same 14.4V power rail, physical form factor, and BMS handshake protocol — one pack covers the full group without modification.
- Bench tested on actual hardware: We cycled the pack through the TFS3031's probe initialisation sequence, where inrush current spikes sharply at sensor power-up. The BMS held the rail stable and did not trip into protection mode across repeated cold starts.
- Calibration cycle before first field deployment: After installing this pack, run a full calibration cycle through the instrument menu before heading to site. The TFS3031 maps battery state during calibration — skipping it causes the low-battery warning to trigger prematurely on the first measurement session, even with a fully charged pack.
BMS cutoff during probe module initialisation on the TFS3031
When the TFS3031 powers up a probe or active sensor module, current draw spikes sharply for 200–400ms before settling to steady-state load. An aged or deeply discharged pack cannot hold the voltage rail through that spike, and the BMS reads it as a fault condition and cuts output. This pack's cells are matched to handle that inrush without triggering protection. If the instrument still shuts down at probe power-up after installing a new battery, confirm the pack is charged above 15.8V before attempting the sequence.
Instrument not recognising new pack after months in storage
Ni-MH packs that sit unused for several months self-discharge below the BMS recovery threshold — the protection circuit enters sleep mode and the instrument sees no battery at all. To recover, connect the charger and leave it for a full charge cycle without interrupting; the BMS needs a sustained low-current input to exit sleep mode before normal charging begins. If the charger LED does not respond within 30 minutes, disconnect, wait 5 minutes, then reconnect — this resets the charger handshake. The pack should respond once cell voltage climbs above approximately 10V.