Fluke BP290 10.8V Digital Multimeter Replacement Battery

Fluke 190 II / 430 II Scopemeter — 10.8V Li-ion Replacement Battery (BP290)

This is a 10.8V, 3400mAh Li-ion battery pack for the Fluke 190 II and 430 II Scopemeter series, including the 123B. It replaces OEM part BP290 directly. The pack powers the meter's display, probe circuits, and data logging systems during fieldwork.

• 190 II and 430 II platform compatibility: Both series run the same 10.8V three-cell Li-ion architecture, share the BP290 connector pinout, and use the same BMS handshake protocol — which is why one pack covers both lines.
• Bench tested on actual hardware: We ran this pack through the Scopemeter's power-on sequence, probe initialisation, and sustained waveform capture. The BMS held steady through the probe power-up current spike without tripping into protection mode.
• First-use calibration cycle: After fitting this pack, run a full calibration cycle through the instrument menu before taking it to site. The 190 II maps battery state during calibration — skipping this step causes the low-battery indicator to trigger early on the first measurement session, even when the pack has good charge remaining.

BMS lockout after the BP290 pack sat unused in a carry case

Li-ion cells self-discharge over time. If the 190 II sits in a case for several months, the pack voltage can drop below the BMS recovery threshold — typically around 2.5V per cell. At that point, the BMS enters sleep mode and the meter shows nothing when you press power. A standard charger will not wake it. Connect the pack to the Fluke charger for at least 30 minutes before attempting to power on — most chargers apply a trickle pre-charge below 3.0V per cell to recover the BMS. If the charger LED stays red past 45 minutes, check cell voltage directly at the pack terminals; anything below 7.5V total indicates deep discharge beyond safe recovery.

190 II shuts down mid-USB transfer to PC

During USB data transfer, the 190 II draws power for the display, active probes, and the USB subsystem simultaneously. This combined load can cause a momentary voltage sag that trips the BMS under-voltage cutoff — particularly if the pack is below 40% charge. The meter shuts off cleanly but the transfer session is lost. To avoid this, ensure the pack is above 60% charge before starting any logging download, or connect the AC adapter during transfer to offload the USB draw from the battery entirely.