Bosch Flexxo Series 4 replacement battery replacement

ID: 200307

Description: This Bosch cordless vacuum was manufactured...

Steps:

1. First, the small handheld unit must be unclipped from the main vacuum cleaner. Then, remove the dust bag unit.
2. Now, remove all visible screws. Do not forget the hidden one in the 2nd photo and the 4 tiny ones on the filter (red arrows).
3. Afterward, it will almost open; it should look like the last picture. However, there are 2 more sneakily hidden screws. See the next step!

4. They are hidden under a plastic cover beneath the handle. You can see a tiny hole under the handle in my mirror. The gentlest way (though difficult) is to use this hole and a small hook to pry the plastic cover on the side upwards as shown in the image. Look at the elongated plastic cover (half-shell); it is only snapped into place.
5. If you do not succeed via the hole (which is actually an unnecessary connector), you can insert a knife into the slot near the power button from above, as shown in picture 2, and remove the cover by prying it to the side, not downwards. Otherwise, the retaining tabs on the top will break off. That is not a big deal, though; it can be closed back up well even without them!
6. Under this cover—which is hard to spot; I searched for 30 minutes wondering why it wouldn't come apart!! Thanks Bosch!—2 Phillips screws appear, see photo no. 3. Then the vacuum cleaner will open completely into 2 parts. Go slowly! Some things will fall out immediately. Look at the relevant parts in the next step first.

7. What comes out when you open it? Note it here: At the top is the cover with the switch, the LED indicator light (at the top of the image in the silver foil), and the spring-loaded release buttons for removing the filter unit on the left and right. Finally, there is the unnecessary connector that sits in the hole at the bottom of the handle. Everything is marked with the red arrows.

8. Now your skill and care come into play. Since the battery pack is not available as a pack—not even from Bosch (=very poor, dear Bosch team!!)—you have to disassemble it completely. First, disconnect the connectors from the PCB (mark them!) and unscrew the PCB from the pack using the 2 tiny Phillips screws.
9. Then it will look like in picture 2. Remove the silver plastic part with the screws. The 6 cells are now installed in a sturdy black plastic carrier housing. First, remove all adhesive strips. Important:
10. Now mark the wire colors very precisely and note which cells they were soldered to!! Otherwise, it will never be able to be charged correctly again. Also, mark the polarity of the cells! You will soon be holding everything individually in your hands.
11. It looks complicated, but it is relatively simple: The 6 cells are soldered to each other in series (always plus to minus). The large 2-pin connector is therefore the minus at the beginning and the red one is the plus of the series circuit. The thin colored wires go in between to each cell to measure the individual voltage during charging. So remember all the colors.
12. Now look at the red arrows: These locking tabs must now be separated by lifting them simultaneously (e.g., slide a washer underneath). There are 2 halves that are clipped together and hold the replacement batteries. Afterward, the cells will be lying in front of you.
13. Now comes the tricky part: simply snip off the cables and first solder the new cells in series as you noted. Ensure that one of them is arranged in a position above the other 5. Please do not solder the cells for too long, and only at the ends; they must only be heated briefly. Risk of explosion!
14. Now check if they fit mechanically into the black housing; if not, make corrections. Then solder on the thin colored cables. Soldering with the solder tabs is quite fiddly; sometimes it solders better if you roughen them slightly. If you now manage to get the cells back into the black housing, you are the greatest!
15. Clip the housing together; in my view, no additional adhesive strip is necessary. As you wish. Then screw it back onto the large silver part, screw on the PCB, and only at the very end insert the connectors. First, reinsert the battery pack with the motor, filter, switch unit, etc., into the housing.

16. When everything looks like it does in the picture, set the power switch to the OFF position! Only then should you reconnect the connectors to the PCB. This provides power and makes it operational. Attention! I just realized you could potentially do this at the very end as well.
17. Before placing the second housing half on, make sure the switch unit is fully equipped with the loose parts, e.g., the spring pusher for the filter unit or the front one. Also, ensure the power switch is correctly inserted into the hole of the switch slider at the bottom, and that the light guide is positioned inside the silver foil.
18. Now place the housing half on and make sure all edges close. Otherwise, a cable might be pinched somewhere, or something might not be snapped into place correctly. The small connector at the bottom of the handle must be inserted exactly into the recess!
19. Before you fiddle the top switch cover into place, screw in a few screws loosely (not all the way) so that the entire part is held together roughly and does not keep falling apart.
20. Now take care of the long switch cover with the semi-circular ends. It is very difficult to insert because it essentially has to lie correctly in the slot all around at the same time. This requires some fiddling, but with a little patience, it will work.
21. Important: Now hold the housing firmly together and switch it on briefly: Does it work? If so, everything is OK. Now screw all the screws back in—please don't tighten them too much, it's all plastic! Tightening them slightly is perfectly sufficient! When it looks like it does in the final picture, attach the filter mat onto the 4 thin pins (clean them beforehand!) and screw the rest shut.
22. Lastly, the small semi-circular cover under the handle, behind which the 2 hidden screws are located, is clipped on. Pay attention to the fact that there are different types of clips on the top and bottom. First the top, then the bottom, and be careful!
23. Now it will suction like on the first day! And since the cells have improved, even longer.