Battery Life - FI-500

FI-500 Fiber Inspector ships with two rechargeable NiMH batteries (1.2 V, 2700 mAh) and a charging cable assembly.  It will also run on two AA Alkaline batteries, but the charger will only charge the NiMH type batteries.   No other battery types are supported.  Do not attempt to recharge non-rechargeable batteries in the FI-500.

We recommend charging the NiMH batteries for 4 hours before you use them for the first time.


Battery Life

  • 3 hours of continuous probe use
  • 6 hours of typical probe use


Charge Time

4 hours minimum


Battery LED States

Red:  Charging

Green:  Fully Charged

Red/Green Alternating:  Wrong type of batteries (NiCad, LiON) are installed. 


FI-500 Display battery icon and LED indicators 


Note:  The FI-500 will operate when connected to the charger cable without any batteries installed.


Removing and Installing the Batteries:



Power Management Settings

In the Tools menu you can adjust the Power Down, Standby and Dim Display settings in order to conserve battery life.  If you make changes, be sure to arrow down to select Save and Exit, then press (F4) OK to save the setting..

Power Down settings can be adjusted to Never, 1, 3, 5, 10, 15, or 30 minute duration.


Replacing the Batteries

Replace the rechargeable batteries after 5 years of moderate use or 2 years of heavy use.

  • Moderate use is defined as recharged twice a week.
  • Heavy use is defined as discharged to cutoff and recharged daily.

DISCONNECT THE CHARGER WHEN REPLACING THE BATTERIES.  If you leave the charger connected, the tester may be unable to accurately determine and display the charge state of the replaced batteries.  A warning message may be displayed:


"Incorrect batteries are installed.

Disconnect the charger and insert

NiMH rechargeable batteries.

Please see your User's Manual for details."


FI-500 Replacement Batteries:  Order FI-BATTERY from a Fluke Networks Authorized Reseller.  

This item is a set of two rechargeable NiMH batteries (1.2 V, 2700 mAh).

Click here for the MSDS sheet for FI-BATTERY