Dyson Type B battery upgrade

So my old Dyson battery was failing was lucky to do 1 room so I purchased 12 x 18650 lithium battery's 3500mah if you see any rated much over this value they will be fake battery and should not be used,

Note: I take no responsibility for any harm or damage that may happen by building this you alone take full responsibility for your actions. lithium battery's can be very dangerous can be hard to put out if the worst was to happen separating the battery is fairly hard this video is for a different battery but will show you the best way to get it apart https://www.youtube.com/watch?v=wIQXNjNGVrk

I decided to hot glue my battery together and then solder them and not use the original holder you may find removing the two centre batterys to be hard as the thermistor is sometimes stuck to them or at least it was for me.

here is some guides on how to do this, this is also a different battery but its basically the same

Part 1
Part 2
Part 3
Part 4

so the main things to b