How to Repair a Sonicare FlexCare Battery

Sonicare FlexCare toothbrushes have a rechargeable lithium-ion battery installed in the handle. After two years, warranty coverage for Sonicare toothbrushes ends. If your battery stops charging, Sonicare suggests there is no way to replace the battery and that you must recycle the old handle and purchase a replacement for $145. Replacing the rechargeable battery helps you avoid the cost of purchasing a brand new unit.

Things You'll Need

• Flat head screw drivers, one normal and one small
• Soldering iron
• Toothpicks
• Lithium-ion battery
• Scissors
• Tweezers or needle nose pliers

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Instructions

Finding a Replacement Battery

• 1

  Insert a screwdriver into the slots at the bottom of the toothbrush handle. Twist counter-clockwise to loosen the internal components from the handle. Push the head of the toothbrush on a table or counter to force the internal components to slide out. Take care not to touch the circuit board.

• 2

  Look at the circuit board and find the two battery ends. Solder connects the ends of the battery to the board. The negative terminal is closest to the bottom of the handle. Jot that down if you're likely to forget which end is negative and which is positive.

• 3

  Use the soldering iron to melt the metal allowing the battery to loosen from the board. Pull it away from the board with the small screwdriver. Set the battery aside.

• 4

  Remove all solder with toothpicks and the soldering iron. When installing the new batteries, you need the holes where the battery connects to be clear of debris. (See reference 4)

• 5

  Note the size and capacity of the drained battery. Purchase a replacement battery that matches the exact specifications.

Installing the New Battery

• 6

  Remove the new battery from the packaging. Use scissors to narrow the metal tabs on each end of the battery. Verify that the narrowed battery tab will fit through the circuit board hole.

• 7

  Insert the battery into the slot behind the circuit board. Use the tweezers or needle nose pliers to gently pull the metal tabs on the batteries through the holes on the front of the circuit board. Make sure the negative end of the battery is closest to the bottom of the handle.

• 8

  Secure the battery to the circuit board by soldering the metal tabs to the hole. Trim any unnecessary metal tab with the scissors.

• 9

  Insert the circuit board back into the handle. Use the screwdriver to twist the circuit board component clockwise to secure it in place.

• 10

  Place the toothbrush on the charging base and let it charge overnight. Test the toothbrush the next morning to verify that the new battery works. If it doesn't, verify that you inserted the negative and positive battery terminal to the correct hole on the circuit board. If it still doesn't work, another component on the circuit board needs repair.