Author Topic: EXFO Max-715B OTDR: Won't Charge Internal Lithium Battery  (Read 750 times)

0 Members and 1 Guest are viewing this topic.

Offline MrMosfetTopic starter

  • Newbie
  • Posts: 1
  • Country: us
EXFO Max-715B OTDR: Won't Charge Internal Lithium Battery
« on: January 08, 2022, 01:29:47 am »
Have an EXFO OTDR that no longer wants to charge the internal battery LiPo battery. All other features/functionality work, if powered from the 9V-18VDC input jack although a battery is need for it to bootup. When on the red LED low battery indicator blinks red indicating a low state of charge... I've been charging the battery manually and have load tested with 100mA->500mA and the output voltage is steady at 3.9VDC

Control board output to the battery ~2.6VDC, I've checked it with input voltages ranging from 9-15VDC and tried sweeping a the thermistor terminal resistance from 1k to 25k and don't see any changes (Batteries thermistor reads ~10k at 75 deg F).  Not the most proficient with board level repairs but can usually poke my way through with a schematic, challenge I'm having is identifying the charge controller with limited success googling most of the chips.

I'm hoping somebody might be able to point out chip most likely related to the LiPo battery charging so that I focus additional research into identifying it
 

Offline abdulbadii

  • Frequent Contributor
  • **
  • !
  • Posts: 350
  • Country: us
Re: EXFO Max-715B OTDR: Won't Charge Internal Lithium Battery
« Reply #1 on: January 18, 2022, 09:24:19 pm »
"Control board output to the battery ~2.6VDC"

Is it easy to find T there, to meter sec. winding output and to know that's value or 3.9 V it is?
 

Offline m3vuv

  • Super Contributor
  • ***
  • !
  • Posts: 1738
  • Country: gb
Re: EXFO Max-715B OTDR: Won't Charge Internal Lithium Battery
« Reply #2 on: January 19, 2022, 11:44:35 am »
Can you not bodge on a TP4056 ,and feed it with a 5v supply and let that  charge it?
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf