Fluke BP1735 Biomedical Replacement Battery 7.2V 2500mAh

Fluke Biomedical Varta / Multimeter P-1505 — 7.2V Ni-MH Replacement Battery (BP1735)

This is a 7.2V, 2500mAh Ni-MH replacement battery for the Fluke Biomedical Varta and multimeter P-1505. It slots into portable diagnostic and test instruments used in medical device testing and biomedical QA environments. Part number BP1735 matches the OEM specification.

• Biomedical Varta and P-1505 platform: Both instruments run from the same 7.2V Ni-MH cell stack and share the BP1735 form factor. The connector pinout and BMS handshake are identical across the platform, so one pack covers both units without any modification.
• Bench tested on actual hardware: We cycled this pack through charge and discharge on the bench with the BMS active. The protection circuit responded correctly to full-charge termination and held the pack stable under the sustained low-current draw typical of sensor and probe operation in these instruments.
• Post-install calibration cycle: After fitting this pack, run a full calibration cycle through the instrument menu before field deployment. The instrument maps battery state during calibration — skipping this step causes premature low-battery warnings during the first measurement session, even with a fully charged pack.

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

Ni-MH cells self-discharge over time, and if the pack drops below the BMS recovery threshold during storage, the protection circuit latches off and blocks charge input. The instrument will show no charging activity even when connected to a known-good charger. To recover the pack, apply a slow pre-charge at around 0.1C — most dedicated Ni-MH chargers do this automatically in recovery mode. Once the cell voltage climbs back above approximately 1.0V per cell, the BMS releases and normal charging resumes.

Instrument shuts down mid-measurement with no low-battery warning

This happens when the probe or sensor module initialises and draws a brief current spike that exceeds the BMS overcurrent threshold — the pack cuts off before the battery indicator has time to update. It is not a capacity issue; the pack can be fully charged and still trip on that startup surge. Aged cells with higher internal resistance make this worse because the voltage sag under load is steeper. Fitting a fresh pack lowers internal resistance and keeps the voltage above the BMS trip point during probe power-up.