Battery Revival

ID: 175512

Description: Most "new" old stock backbeat fits suffer from...

Steps:

  1. First we must check if this device would benefit from battery revival / recharging. Plug in a charger and make sure that the ear piece red lights illuminate. This will indicate that the onboard charger, regulator, and electronics are functioning.
  2. However, if the unit is incapable of holding a charge, you should see that it will pull no current from the wal-wart charger. Not required, but you can see charging current from a USB power monitor such as the Klein Tool ET920.
  3. If the red lights do not turn on, then this repair guide will not able to assist you; a deeper level repair is required.
    4. Step image Step image
  4. Identify the left earpiece.
  5. Stick a dull knife or pointed object under the gasket opposite side of the ear loop.
  6. Pull back the gasket covering the edge of the pushbutton cover; taking care to not rip or tear the rubber. If glue is holding onto the rubber, use an exacto knife to carefully cut it back.
    7. Step image Step image
  7. Carefully separate the glue from the tangs holding the button cover to the battery assembly and outter housing.
  8. There are four tangs in total, three are easy to access with the gasket out of the way.
  9. I used an exacto knife, but becareful to not cut any wires coming down from the ear loop, or destroying any of the detents which hold the button cover in place.
  10. Take your time, the attachment to the battery housing is much stronger than the strength of the plastic cover.
    11. Step image Step image
  11. With the button cover removed, you can run a dull knife down through the sides to free up the glue holding the earpiece to the main housing.
  12. Apply gentle pressure to pull the earpiece away. Be careful to not rip the very short speaker wires.
    13. Step image Step image Step image
  13. With the earpiece removed, we can get access to the battery charging terminals. Identify the location of the cell positive and negative terminals.
  14. The negative terminal (cell ground) is a large soldered tab. The positive terminal is the second lead from the square IC chip.
  15. Remove the silastic wire bonding to expose the ground and positive lead. De-solder and tape back the cell positive ground to protect the unit's electronics from the charging current in the next step.
  16. Solder appropriately colored wires on to the two terminals.
  17. Check battery voltage, it should be at or near 0V.
    18. Step image Step image
  18. Apply a charging profile consistent with the battery datasheet. Varta CP1654.
  19. If you lack a battery charger, a low voltage supply through a current limiting resistor can work. Limit charging to 1C rate (<60mA) and increase voltage periodically as battery voltage recovers.
  20. If the charge voltage does not raise above a 1V in a few minutes, the cell is most likely damaged beyond repair.
  21. DO NOT APPLY VOLTAGE OR CURRENTS GREATER THAN THAT SPECIFIED IN THE DATASHEET. THIS MAY RESULT IN DAMAGE TO THE CELL, ELECTRONICS, OR PERSONAL INJURY!
  22. If you do not know how to properly recover the battery, it is recommended that you stop charging at ~3.5V, and allow the onboard charger to complete the rest after re-assembly.
    23. Step image Step image
  23. Solder the positive battery wire back to the second position solder pad.
  24. Apply glue to cover the exposed wire and ground terminals.
  25. Continue reassembly in reverse order.
  26. Once assembly is complete, complete the charging process with the USB cable.
  27. If you have it, it is recommended to monitor the charge with a USB power meter.
  28. Note: the battery will require a few deep cycles (empty -> full) to re-stabilize after being drained for an extended period of time.
    29. Step image
Back