Master Thesis - OUFTI-1

In this design, the battery Printed Circuit Board (PCB) was suspended to the xEPS
card, using four T i screws. The two PCBs are separated by four T i spacers and thermal
washers are placed at the level of the battery PCB to isolate it thermally.
The main problem of this design was the available space between the batteries and the
electronic cards situated under and above them, as it is shown in Figure 3.2.
Figure 3.2: Available space under and above the batteries
The available space between the lower battery and the highest component above the
EPS card is given in Equation (3.2.1) and the distance between the upper battery and the
highest component under the xEPS card is given in Equation (3.2.2).
d Battery - EPS = 5.57 − 4.8 = 0.77 mm (3.2.1)
d Battery - xEPS = 4.83 − 1.5 = 3.33 mm (3.2.2)
So, it can already be noted that the position of the batteries inside the satellite is not
optimal. In addition, due to the restricted value of the distances which separate these
components, several problems can occured, especially concerning the vibrations. Indeed,
the batteries could collide one of the two electronic cards and cause important damages on
it.
In addition to this restricted available space, it appeared, after a test under vacuum
conditions, that the batteries bulged (as shown in Figure 3.3). This increase the problem of
the available space and, moreover, can aect the electrical performance of the batteries. To
avoid this problem, the solution which was investigated, was to encapsulate the batteries
inside a box.
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