While rechargeable batteries are the obvious choice for use in equipment which is in use continuously, disposable types have economic and logistic advantages for some applications – the batteries are more expensive long term but no charger is needed. Also primary batteries have up to 4 times the available capacity of their nickel cadmium equivalents with less weight. Details of disposable batteries with some standard nickel-cadmium rechargeable equivalents are given in Table 21.1.
Lithium primary batteries are now available and have the following qualities:1. A high cell voltage of 3.6 V on load. The voltage is constant – after an initial fall when load is first applied – until discharged when a rapid fall occurs.
2. An operating temperature range of −55æCto +75æC is possible.
3. Energy densities up to 630 mWh/g. A standard AA size cell has a power/weight ratio of 340 mWh/g.
4. Long shelf life. Ten years at room temperature for a 10% fall in capacity is envisaged.
They have a disadvantage in that fire, explosion or severe burns may result if the batteries are mistreated. They must not be recharged, disassembled, heated above 100æC, incinerated or the contents exposed to water.
One use of lithium batteries is as a power source for memories but protection against charging is needed. Figure 21.1 shows a typical circuit.
Vcc D2 C MOS RAMcarbon AAA HP 16 RO3 10.5 – 45 Cap and base 0–10 000 8.5
AA HP7 R6 14.5 – 50.5 Cap and base 0–75 16.5
AA C7 R6 14.5 – 50.5 Cap and base 0–75 16.5
C SP11 R14 26.2 – 50 Cap and base 20–60 45 C HP11 R14 26.2 – 50 Cap and base 0–1000 45 C C11 R14 26.2 – 50 Cap and base 0–5 45 D SP2 R20 34.2 – 61.8 Cap and base 25–100 90 D HP2 R20 34.2 – 61.8 Cap and base 0–2000 90 4.5 AD28 3R25 101.6 34.9 105 Socket 30–300 453.6
1289 3R12 62 22 67 Flat springs 0–300 113 6.0 PP8 4-F100-4 65.1 51.5 200.8 Press studs 20–151 1100 PJ996 4-R25 67 67 102 Spiral springs 30–300 581 991 135.7 72.2 125.4 Two screws 30–500 1470 9.0 PP3-P 6-F22 26.5 17.5 48.5 Press studs 0–50 39 PP3-C 6-F22 26.5 17.5 48.5 Press studs 0–50 39 (continued overleaf)
Maximum dimensions (mm)
PP3 6-F22 PP4 6-F20 PP6 6-F50-2 PP7 6-F90 PP9 6-F100 PP10 6-F100-3
15.0 B154 10-F15
B121 10-F20
22.5 B155 15-F15
B122 15-F20
Manganese ED 1.5 MN1300∗ LR20 alkaline C MN1400∗ LR14 AA MN1500∗ LR6 AAA MN2400∗ LR03 N MN9100∗ LR1 Mercuric 1.35/1.4 RM675H NR07 oxide RM625N MR9 RM575H NR08 RM1H NR50 Silver oxide 1.5 10L14 5R44
10L124 5R43
10L123 5R48
10L125 5R41
Nickel 1.25 NC828 – cadmium AA NCC50 – C NCC200 – D NCC400 – 10.0 NC828/8 – 12.0 10/2250K – 9.0 TR7/8 (DEAC) AA 1.25 501RS (DEAC) C RS1.8 (DEAC) D RS4 (DEAC) 11.6 – 3.5 Cap and base (button) 0.12† 1.4 16.4 – 16.8 Cap and base (button) 1.00† 12.0 11.56 – 5.33 Cap and base (button) 0.13† 2.2 11.56 – 4.19 Cap and base (button) 0.13† 1.7 7.75 – 5.33 Cap and base (button) 0.08† 1.0 7.75 – 3.58 Cap and base (button) 0.04† 0.8 Button 0.28† 16.5 See HP7 Button 0.60† 30.0 See HP11 Button 2.00† 78.8 See HP2 Button 4.00† 170.0 Button stack 0.28† 125.0 Button stack 0.225† 135.0 See PP3 Press studs 0.07† 45.0 See HP7 Press studs 0.50† 30.0 See HP11 Press studs 1.80† 65.0 See HP2 Press studs 4.00† 150.0
26.5 17.5 48.5 Press studs 0–10 38
26.5 – 50 Press studs 0–10 51
36 34.5 70 Press studs 2.5–15 142
46 45 61.9 Press studs 5–20 198
66 52 81 Press studs 5–50 425
66 52 225 Socket 15–150 1250
16 15 35 End contacts 0.1–0.5 14.2
27 16 37 End contacts 0.1–0.1 21
16 15 51 End contacts 0.1–0.5 20
27 16 51 End contacts 0.1–1.0 32
34.2 – 61.5 Cap and base 10.00† 125
26.2 – 50 Cap and base 5.50† 65
14.5 – 50.5 Cap and base 1.80† 23
10.5 – 44.5 Cap and base 0.80† 13
12 – 30.2 Cap and base 0.65† 9.6
11.6 – 5.4 Cap and base (button) 0.21† 2.6
15.6 – 6.2 Cap and base (button) 0.25† 4.3
† Capacity in ampere hours.
‡BEREC types unless otherwise indicated. ∗Also Duracell (Mallory).