Double Your Field Testing Runtime with High-Capacity Fluke Power Maximize productivity on demanding job sites. This BP291 'Double Capacity' replacement battery delivers a robust 4800mAh of power, effectively doubling the runtime compared to standard Fluke batteries for compatible tools. Engineered for a range of critical Fluke industrial testers, it ensures your 190-Series oscilloscope, power quality analyzer, or acoustic imager keeps working through the longest shifts.