Anritsu MW9070 Replacement Battery 10.8V 2500mAh NiMH

Anritsu MW9070 / MW9070B — 10.8V Ni-MH Replacement Battery (MU909814)

This is a 10.8V 2500mAh Ni-MH replacement battery for the Anritsu MW9070 and MW9070B site master cable and antenna analyzers. It slots into the same battery bay as the original MU909814 pack and restores field power for on-site RF measurements. Capacity is 2500mAh (27Wh), matched directly to the original specification.

• MW9070 and MW9070B compatibility: Both models run on the same 10.8V three-cell Ni-MH voltage rail and share the identical connector and BMS handshake protocol. Swapping between variants requires no configuration change — the instrument reads state-of-charge from the same cell taps on both.
• Bench tested on actual hardware: We cycled this pack through the MW9070 instrument under field-representative RF sweep loads. The BMS held stable across repeated measurement sessions, and charge termination triggered cleanly at full capacity without false cutoffs.
• Calibration cycle before first field deployment: After fitting this pack, run a full calibration cycle through the MW9070 instrument menu before taking it into the field. The instrument maps battery state during calibration — skipping this step causes premature low-battery warnings on the first measurement session, even when the pack is fully charged.

MW9070 BMS lockout after the analyzer sat unused in a carry case for months

Ni-MH cells self-discharge at roughly 1–2% per day at room temperature. After several months in a carry case, an unused pack can drop below the BMS recovery threshold — typically around 9V for a 10.8V three-cell pack — and the protection circuit locks out charge input entirely. The instrument then shows no charge activity and may not power on at all. To recover, connect the charger and leave it uninterrupted for at least two hours; most BMS circuits re-initialise once cell voltage climbs back above the 9V recovery floor.

Readings resetting or dropping out mid-sweep during a logging session

Sustained RF sweep loads draw more current than the idle display state, and a degraded or partially charged Ni-MH pack can sag below the MW9070's operating voltage floor during that sustained draw. When cell voltage dips momentarily, the instrument interprets it as a low-power condition and resets the active measurement — even if the battery indicator still shows charge remaining. The fix is to ensure the pack is fully charged before any logging session and to verify resting voltage sits at or above 12.0V before powering on. If sag resets persist on a fully charged pack, the cells are worn and the pack needs replacing.