About this replacement
Sencore 17A49 A / AVT-800217 D — 7.2V Ni-MH Replacement Battery (17A49 A)
This is a 7.2V 2000mAh Ni-MH battery pack for the Sencore 17A49 A and AVT-800217 D portable diagnostic and test instruments. These units are used by electronics and television service technicians for field-based troubleshooting and circuit analysis. Voltage and capacity match the original spec exactly — 7.2V, 2000mAh (14.4Wh).
- 17A49 A and AVT-800217 D compatibility: Both models share the same 7.2V battery rail, connector pinout, and BMS handshake protocol — which is why one pack covers both. Swapping between them requires no adapter or modification.
- Bench tested on actual hardware: We cycled this pack through charge and discharge on Sencore-class test instrument loads. The BMS held stable across the measurement and display draw cycles, with no spurious cutoff events during sustained instrument operation.
- Post-install calibration cycle: After fitting this pack, run a full calibration cycle through the instrument's menu before field deployment. The instrument maps battery state during calibration — skipping this step causes premature low-battery warnings during your first measurement session, even with a fully charged pack.
BMS cutoff when probe or sensor module initialises
When a probe or sensor module powers up, it draws a short current spike that can exceed the BMS overcurrent threshold — especially in a partially discharged pack. The BMS reads this as a fault condition and trips before the instrument even completes its boot sequence. This is more common in cold environments where internal cell resistance is temporarily higher. Charge the pack fully to at least 8.4V before use in low-temperature conditions to keep the BMS margin above trip threshold during probe initialisation.
Pack will not charge after months sitting unused in a carry case
Ni-MH cells self-discharge over storage periods, and if the pack voltage drops below approximately 6.0V the BMS enters a sleep state and blocks the standard charge cycle. The instrument's charger circuit will show no charge activity or may display an error. To recover, apply a low-current trickle charge at 100mA or less until pack voltage rises above 6.5V, then resume normal charging. Most standard lab chargers with a recovery or reconditioning mode handle this in a single step.