Page 365 - Lindens Handbook of Batteries

14.30 PriMAry BATTerieS

Discharge characteristics at +25°C
4.0

3.5

3.0
Volts 2.5

2.0
94 Ω 180 Ω 560 Ω 1.8 KΩ 3.6 KΩ 18 KΩ
~35 mA ~20 mA ~4 mA ~2 mA ~1 mA ~0.2 mA
(7 Ah) (13.5 Ah) (19.0 Ah) (18.8 Ah) (18.4 Ah) (17 Ah)
1.5

1.0
1 10 100 1000 10000 10,0000
Hours
(a)

Voltage vs. temperature
3.7
3.6
3.5
3.4 0.2 mA
Volts 3.3 0.5 mA
3.2 1 mA
3.1 4 mA
3.0 20 mA
35 mA
2.9
–60 –40 –20 0 20 40 60 80
°C
(b)
FIGURE 14.17 (a) Discharge characteristics of high-capacity Li/SOCl cylindrical D-size bobbin bat-
2
tery at +25°C. (b) Operating (plateau) voltage of the same battery as a function of temperature at various
drain rates. 24

rates and temperatures. The relationship of capacity with current is given in Fig. 14.18, showing
the performance from -40 to 80°C. The Li/SOCl cell is capable of performance at unusually high
2
temperatures. At 145°C, (Fig. 14.19) the cells deliver most of their capacity at high rates and up to
70% at low discharge rates (20 days of discharge). Li/SOCl cells are used to build battery packs
25
2
that are employed in oil exploration and most withstand temperatures to 150°C as well as high levels
of shock and vibration.
Figure 14.20 shows the behavior of AA cells on continuous low-rate discharge at 25°C. The dis-
charge curve is very flat at these low-current drains, but capacity loss below the 2.4 Ah rating occurs
below the 1000-hour rate due to parasitic self-discharge.
The capacity or service life of the high-capacity bobbin-type Li/SOCl cell, normalized for a 1-kg
2
and 1-L size cell, at various discharge temperatures and loads, is summarized in Fig. 14.21.