Replacing Philips FC 6148 handheld vacuum cleaner batteries

Remove all attachments, leaving only the base unit.

Unscrew the five Phillips screws.

You have to disassemble the device into two halves. To do this, cut the sticker at the seam with a sharp tool.

Take a plastic lever tool and carefully split the device into two halves. It probably is stuck a little.

Now is a good time to give the inside of the appliance a good clean, especially all the foam filters.

The batteries - shown here in green - are easy to see. They are held in the device by rubber buffers.

You need three 18650 batteries with U-shaped solder tabs. The higher the capacity, the longer you can vacuum. Use types with a nominal voltage of 3.7 V and a charging voltage of 4.1 V.

To be on the safe side, measure the voltage of each cell. They should all be the same.

Carefully lift out the batteries. A fuse and a thermal sensor are glued to the first and third battery.

Remove the adhesive tapes and carefully push the fuse and the thermal sensor to the side.

In the third picture you can see the thermal sensor. Note how it is guided through a groove in the rubber buffer and rests against the battery.

All solder joints are secured with heat-shrink tubing. Cut all heat-shrink tubing with a sharp tool and remove it.

Now comes the main work: soldering. Get some wide heat-shrink tubing that fits over the soldering tabs.

Desolder the old batteries piece by piece - you can also pinch off the cables - and solder them to the new batteries in the same way:

Slide on suitable pieces of heat-shrink tubing before soldering.

Heat the heat-shrink tubing until it tightens against the soldering tabs.

Tape the fuse and the heat sensor in place with insulating tape.

Insert the batteries.

Check the polarity of the batteries once more.

Minus

Plus

Switch on the device for testing.