challenge: how to reassemble a battery with new cells

Hello, recently my laptop's battery life finished, so i tried to replace the cells inside the battery pack.

The computer is a benq joybook r23e and the battery model is BP-8889L

I bought newer rechargeable cells. Exactly the same model.

When i replace all the cells in the same position, one of them get so hot and starts to smell like burning.

I think i'm placing the same position as the original cells because i made a scheme.

the position is:

|[+ -]|[+ -]|[+ -]|

|[xxx]|[xxx]|[xxx]|

|[+ -]|[+ -]|[+ -]|

b____y_____o____r

where | is a metal stripe connected to a cable

and [+ -] is a battery... and characters b, y, o, r are coloured cables connected to the metal stripes (|)(black, yellow, orange and red) and [xxx] are plastic cylinders of unused slots.

So i don't know what i'm doing wrong.

If i can put the batteries without burning it, i just wanna know if i can add 3 more cells to convert the battery from 6 to 9 cells and improve the battery pack.

Thankyou so much for your attention.