GW Instek LCR-1000 LCR-305 Replacement Battery 7.4V 1500mAh

GW Instek LCR-1000 — 7.4V Li-Polymer Replacement Battery (LCR-305)

This 7.4V 1500mAh Li-Polymer pack replaces the OEM LCR-305 battery in the GW Instek LCR-1000 precision LCR meter. The LCR-1000 is a portable impedance measurement instrument used in lab and field environments to test inductance, capacitance, and resistance. Rated at 11.1Wh, this pack restores full portable operation when the original cell degrades or no longer holds a charge.

• LCR-1000 fit: The LCR-305 footprint is specific to the LCR-1000 chassis — 109.00 × 51.20 × 5.20mm with a matched connector and BMS handshake that the instrument firmware expects before enabling the measurement circuits. No other GW Instek LCR model uses this pack geometry.
• Bench tested on actual hardware: We ran this pack through the LCR-1000's power-up sequence and cycled it across multiple measurement sessions. The BMS responded correctly to the instrument's initialisation current draw and held voltage steady across sustained component-testing loads without triggering a cutoff event.
• Post-install calibration step: After fitting this pack, run a full calibration cycle through the instrument's menu before your first measurement session. The LCR-1000 maps battery state during calibration — skipping this step causes the low-battery indicator to fire prematurely because the firmware is still referencing the old cell's voltage curve.

BMS lockout after the LCR-1000 sat unused in a carry case for months

Li-Polymer cells in low-draw instruments self-discharge slowly during storage. If the LCR-1000 sits unused long enough, the pack voltage drops below the BMS's minimum recovery threshold — typically around 2.5V per cell — and the BMS enters a protective lockout state. In this state the instrument will not power on and the charger may show no activity. Applying a compatible charger for 15–30 minutes at a trickle rate is usually enough to bring the cell voltage above the recovery threshold and unlock the BMS, after which normal charging resumes.

Readings drifting or resetting mid-session during sustained component logging

When the LCR-1000 runs extended logging sessions — repeatedly exciting components and sampling impedance values — the sustained current draw can cause a degraded cell to sag below the instrument's minimum operating voltage momentarily. That voltage dropout is enough for the firmware to reset the measurement state, which shows up as drifting readings or a mid-session restart. A new pack with a healthy internal resistance holds the voltage rail stable under that load. If dropout persists after fitting a new pack, check that the battery contacts inside the compartment are clean and making full contact — oxide on the pads adds resistance that compounds the sag.