Fluke BT521 Battery Analyser

  • Flukes most advanced battery analyser
  • Temperature measurements of negative battery post
  • Wireless communication to Fluke Battery Analyse mobile App
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Fluke BT521 Battery Analyser

The Fluke BT521 is Flukes most advanced BT500 series battery analyser for test and measurement batter systems. The user is able to incorporate temperature testing into their testing thanks to the BTL21 test leads. The BTL21 Intelligent Test Probes with long and short extenders, built in LCD display for measurement viewing and speaker for visual and audible feedback. The integrated infrared temperature sensor allows for temperature measurements on the negative battery post to be taken with every test.

The Fluke BT521 Battery Analyser is made for use with stationary and battery back up systems allowing for voltage, resistance and ripple voltage. The resistance of the intercell connection between batteries in a string can be conducted using the Intercell strap resistance test and data management

The intuitive user interface and compact rugged design of the Fluke BT521 ensure an optimum performance, test results and reliability. Combined visual and audible feedback cues reduces the risk of measurement confusion. The device also offers users the chance to configure values and thresholds for resistance and voltage. Users can configure a maximum of 10 sets of thresholds and receive Pass/ Warning/ Fail indications after each test measurement. Results can be compared after each measurement via the visual and audible cues. Up to 999 records can be stored in the internal memory, each with a measurement position and time stamp.

The Fluke BT521 includes ergonomic test leads featuring rugged coaxial two pole kelvin test point with remote save button, reducing the test time. Long reach, straight and angled probes for double stacked cells. Included with the BT520 are intelligent test probes automatic and manual sequence testing of battery strings using the sequence measurement mode.

The Fluke BT521 has a rechargeable battery life of eight hours continuous use. Safety rated to 6000V CATIII and IP40 rated the Fluke BT521 allows for safe measurement all around the battery power supply equipment. Also included is a large soft carry case for added protection and transportation of the device.

Fluke Battery Management Software

All measurement recordings are automatically captured on the BT520 using AutoSave and allow for instance reviewing on the instrument. Data can be downloaded straight from the device to a PC via the USB port. The measurement data and battery profile data is stored and archived using the management software. Users are able compare trends for analysed. Reports can be generated for measurement data, battery profile and analysis information.

  • Quick view of saved readings
  • Profile management
  • Histogram of a battery string with end-user defined threshold
  • Historical trend data of batteries
  • Multiple rounds ion discharge Voltage
  • Quick report generation
  • Upgrade Fluke battery analyser firmware
  • Switch measurement results between conductance and resistance readings

Fluke Battery Analyse mobile App

The Fluke BT521 has wireless capability allowing user to use the Fluke Battery Analyse App (Fluke BA App). Users are able view profiles and associated test results from the battery analyser. Test results and profile can be sent via email with csv data format

Key Features

  • Battery Voltage
  • Discharge Voltage
  • Ripple Voltage test
  • Meter and Sequence modes
  • Threshold and warning
  • Intercell strap resistance test and data management
  • Autohold
  • Autosave
  • Fluke battery management software
  • Fluke Battery Analyse mobile App compatible
  • Comprehensive logging up to 999 records
  • Optimised user interface
  • 8 hours continuous use battery life
  • USB port for fast download
  • CAT III 600 V, 1000 V dc max. rated for safe measurements all around the battery power supply equipment


Fluke 500 series Battery Analyser Comparison table

  Fluke BT510 Fluke BT520 Fluke BT521
Resistance (mΩ)
Battery Voltage
Voltage DC
Voltage AC and Frequency (HZ)
Ripple Volt
BTL20 Intelligent Test Probe set    
Temperature of negative battery post using BTL21 straight probes    
DC and AC current (and frequency)    
DMM Mode
Sequence Mode
Discharge Measurement Mode
Automatic Measurement Save
Wireless Communication    
Memory View

What's In The Box?

  • Fluke BT521 Battery Analyser
  • 4 Wire Test pin
  • BTL10 basic test lead
  • TL175 TwistGuard test leads with adaptor
  • BTL21 intelligent test probe set with extender and temperature sensor
  • i410 AC/DC Current Clamp
  • BP500 Lithium-ion Battery
  • BC500AC Charger
  • USB 1m cable
  • Shoulder strap
  • Belt strap
  • Magnetic hanging strap
  • FlukeView® battery management software
  • Soft carry case
  • 2 x spare fuses
  • 100 paper battery tags

Battery resistance

  • Range: 3 mΩ/ Resolution: 0.001mΩ/ Accuracy: 1% + 8
  • Range: 30 mΩ/ Resolution: 0.01mΩ/ Accuracy: 0.8% + 6
  • Range: 300 mΩ/ Resolution: 0.1mΩ/ Accuracy: 0.8% + 6
  • Range: 3000 mΩ/ Resolution: 1mΩ/ Accuracy: 0.8% + 6


  • Range: 6V/ Resolution: 0.001V/ Accuracy: 0.09% + 5
  • Range: 60V/ Resolution: 0.01V/ Accuracy: 0.09% + 5
  • Range: 600V/ Resolution: 0.1V/ Accuracy: 0.09% + 5
  • Range: 1000V/ Resolution: 0.1V/ Accuracy: 0.09% + 5

Vac (45 Hz to 500 Hz with 800 Hz filter)

  • Range: 600V/ Resolution: 0.1V/ Accuracy: 2% + 10

Frequency (displayed with Vac and Aac)2

  • Range: 500Hz/ Resolution: 0.1Hz/ Accuracy: 0.5% + 8

Frequency (displayed with Vac and Aac)2

  • Range: 500Hz/ Resolution: 0.1Hz/ Accuracy: 0.5% + 8

AC voltage ripple (20KHz Max)

  • Range: 600mV/ Resolution: 0.1mV/ Accuracy: 3% + 20
  • Range: 6000mV/ Resolution: 1mV/ Accuracy: 3% + 10

ADC/AAC (with accessory Fluke i410)

  • Range: 400A/ Resolution: 1A/ Accuracy: 3.5% + 2


  • Range: 0ºC to 60ºC/ Resolution: 1ºC/ Accuracy: 2ºC (4ºF)

Meter Mode

  • 999 Records for each measurement position with time stamp

Sequence mode

  • Up to 100 profiles and 100 profile templates (each profile stores up to 450 batteries) with time stamp

General Specifications

  • Size (H x W x D): 22 x 10.3 x 5.8cm (9 x 4 x 2in)
  • Weight: 850g (1.9lb)
  • Screen Dimensions: 7.7 x 5.6cm (3 x 2.2in)
  • Interface: USB mini

Environment Specifications

  • Operating temperature: 0ºC to 40ºC
  • Storage temperature: -20ºC to 50ºC
  • Lithium-ion battery charging temperature: 0ºC to 40ºC
  • Operating humidity: Non-condensing (10°C)/ <=80% RH (at 10°C to 30°C)/ <=75% RH (at 30°C to 40°C)
  • Operating altitude: Sea level to 2000 meters
  • Storage altitude: Sea level to 12,000 meters
  • IP rating: IP40
  • Radio: FCC CLass A
  • Vibration requirements: MIL-PRF-28800F: Class 2
  • Drop test requirements: 1 meter
  • Temperature coefficients: Add 0.1 x specified accuracy for each degree C above 28°C or below 18°C
  • Safety compliance: 600V CAT III
  • EMC: IEC 61326
  • ROHS: China, Europe
  • Battery compliance: UN38.3, UL2054, IEC62133 and 2 G per IEC68-2-26, 25G, and 29
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pdf Fluke 500 Series Battery Analysers Datasheet pdf 907.4 KB Download