About this replacement
Megger TDR2000/2R Echometer — 9.6V Ni-MH Replacement Battery (TDR2000-C)
This is a 9.6V Ni-MH 2000mAh (19.2Wh) replacement battery for the Megger TDR2000/2R echometer. It fits the TDR2000/2R time-domain reflectometer used for locating faults, breaks, and impedance mismatches in buried cables and overhead lines. Direct swap for the OEM TDR2000-C pack.
- TDR2000/2R platform fit: The TDR2000/2R uses a 9.6V eight-cell Ni-MH pack with a specific connector orientation and BMS handshake that governs low-voltage cutoff during pulse transmission. This replacement matches that cell count, voltage rail, and connector so the instrument's power management circuitry reads the pack correctly.
- Bench tested on actual hardware: We cycled this pack through TDR pulse sequences and monitored BMS response at the discharge cutoff threshold. The pack sustained the instrument's transmit-pulse load without triggering premature cutoff, and the BMS cleared correctly on recharge.
- Post-install calibration on the TDR2000/2R: After fitting this battery, run a full calibration cycle through the instrument menu before field deployment. The TDR2000/2R maps battery state during calibration — skipping this step causes premature low-battery warnings during the first measurement session, even with a fully charged pack.
TDR2000/2R shutting down mid-pulse during cable fault location
The TDR2000/2R generates a high-voltage pulse to send down the cable under test. That pulse draw is brief but sharp — it can spike current draw beyond what an aged or partially discharged Ni-MH pack can deliver cleanly. When the BMS sees voltage sag cross its cutoff threshold during that spike, it shuts the instrument down immediately. A fresh, fully charged pack eliminates the sag. If shutdowns persist after fitting a new pack, confirm the battery has completed a full charge cycle before field use — Ni-MH cells do not reach rated voltage after a partial charge.
Pack will not charge after the instrument sat unused in a carry case for months
Ni-MH cells self-discharge over storage — if the TDR2000/2R sat unused long enough, the pack voltage can drop below the charger's detection threshold and the charger will not initiate a charge cycle. This is a BMS sleep state, not a dead pack. Connect the battery to the charger and leave it for 30–60 minutes; many chargers apply a trickle voltage that recovers the pack above the detection floor. If the charger still shows no activity, check that the pack voltage measures above 7.2V with a multimeter — below that, a dedicated Ni-MH recovery charger with a force-charge mode is required.