Traduzione in corso passo 7
On these last photos we can see the way these 4 li-ion cells are connected. Spot welded in two places. Four 3,7V cells in series will produce the 14,4V as advertised.
There is also a temperature probe, which most certainly is a thermal resistor, freely stuck between two inner cells.
There is no control board in the battery cell, which really improves the durability. The function of control board was moved into the charger and the drill, but that doesn´t affect the price of these battery packs.