Master Thesis - OUFTI-1

A test under vacuum conditions was performed on these batteries and it appeared that
the Kokam bulged and not the Varta. However, it should be noted that batteries from
Varta presented several uncertainties in relation to their electrical capacity evolution in
time. In addition, these batteries were no longer provided by the industry and, for the
remaining ones, the storage conditions were not known. So, it was decided to use batteries
from Kokam.
The main selection criteria are: dimensions, mass, electrical capacity and, last but
not least, reliability. Accounting for these restrictions, three batteries were selected. Their
properties are available in Table 3.3. It should be noted that the electrical capacity of these
batteries is given for standard conditions (T = 25 ◦ C, V = 2.7 − 4.2 V and q = 0.5 C).
Batteries
Length Width Thickness Mass Electrical capacity
(mm) (mm) (mm) (g) (Ah)
SLP B 554374H 73.5 ± 0.5 42.5 ± 0.5 5.4 ± 0.2 32 ± 1 1.25
SLB 603870H 69.5 ± 0.5 37.5 ± 0.5 6.5 ± 0.2 32 ± 1 1.5
SLP B 723870H4 70 ± 0.5 37.5 ± 0.5 7.2 ± 0.2 37 ± 1.5 1.5
Table 3.3: Properties of several batteries from Kokam [36]
Considering the electrical capacity, OUFTI-1 needs 1.2 Ah. So, the rst battery can not
be selected because the Margin of Safety (MoS) is too small in this case. In addition, this
battery has dimensions that do not allow to include it in the available space described in
Figure 3.6. Now, if the physical properties are also taken into account, the better solution
is to use the battery Kokam SLB 603870H, which is lighter and smaller than the other
one. A picture of this battery is presented in Figure 3.7. Its datasheet is available in
appendix D.
Figure 3.7: Battery Kokam SLB 603870H
This choice, which fullls all the requirements of Structure & Conguration (STRU)
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