Page 497 - Battery Reference Book

48/4 Taper charging of lead-acid motive power batteries

48.1.2 Pre-programmed chargers is reached, and must continue to fall as the gassing
rate increases; thus, this type of charger is limited to
When 10 h or more recharge time is available, a single- a minimum charge time of 10 h.
taper charger is used. This type of charger incorporates When less than 10h recharge time is available,
a voltage-sensing device set to operate when the bat- a two-step taper charger is used, enabling battery
tery voltage reaches 2.35 V/cell (42.3 V overall on an manufacturers' recommendations to be met by using a
18-cell battery). At this voltage a timing device is higher current at the start of charge and a reduction to
started which will terminate the charge after a prede- a lower level once the gassing point has been reached.
termined but adjustable period. As stated previously, As with the single-taper charger, a voltage-sensitive
a discharged battery can absorb a high current during relay starts a timing device at the gassing point, but in
the early part of charge, but there is a limit to the safe this case it has a second function, which is to operate
current after the gassing point has been reached. a contactor, which reduces the current to the required
With a single-taper charger the current must have finishing rate. After 2.35 V/cell, both the single and
fallen to a safe value by the time the gassing point two-step taper chargers have similar characteristics. In

Table 48.1 Range of Chloride Legg Spegel chargers
Battery ampere hour capacity (5 h rate) with time available for recharge Starting
current
71h 8h 8ih 9h 91h 10h 10th llh llih 12h 12th 13h 131h 14h
(A)
25 26 27 29 30 31 32 33 35 36 37 39 40 41 5
50 53 55 57 60 62 64 67 69 72 75 78 80 83 10
75 79 82 86 89 93 96 100 104 108 112 116 120 124 15
100 105 110 114 119 123 128 133 139 144 155 155 160 165 20
125 132 137 143 149 154 160 167 174 180 187 194 200 207 25
150 158 165 171 179 185 192 200 208 216 224 233 240 248 30
175 184 192 200 208 216 224 233 243 252 26 1 27 1 280 289 35
200 211 220 229 238 247 256 267 278 288 299 310 320 331 40
225 237 247 257 268 27 8 288 300 313 324 336 349 360 372 45
250 263 275 286 298 308 321 333 347 360 373 388 400 413 50
275 289 302 314 327 340 353 367 382 396 410 426 440 455 55
300 316 330 343 357 370 385 400 417 432 448 465 480 496 60
325 342 357 371 387 40 1 417 433 452 468 485 504 520 537 65
350 368 385 400 417 432 449 467 486 504 522 543 560 579 70
375 395 412 429 446 463 48 1 500 521 540 560 581 600 620 75
400 421 440 457 476 494 513 533 556 576 597 620 640 66 1 80
425 447 467 486 506 525 545 567 590 612 634 659 680 702 85
450 474 495 514 536 556 577 600 625 647 672 698 720 744 90
475 500 522 543 565 586 609 633 660 683 709 736 760 785 95
500 526 549 571 595 617 64 1 667 694 719 746 775 800 826 100
525 552 577 600 625 648 673 700 729 755 784 814 840 868 105
550 579 604 629 655 679 705 733 764 791 821 853 880 909 110
575 605 632 657 685 710 737 767 799 827 858 891 920 950 115
600 632 659 686 714 741 769 800 833 863 896 930 960 992 120
650 684 714 743 774 802 833 867 903 935 970 1008 1040 1074 130
700 737 769 800 833 864 897 933 972 1007 1045 1085 1120 1157 140
750 789 824 857 893 926 962 1000 1042 1079 1119 1163 1200 1240 150
800 842 879 914 953 988 1026 1067 1111 1151 1194 1240 1280 1322 160
850 895 934 971 1012 1049 1090 1133 1181 1223 1269 1318 1360 1405 170
900 947 989 1029 1071 1111 1154 1200 1250 1295 1343 1395 1440 1488 180
950 1000 1044 1086 1131 1173 1218 1267 1319 1367 1418 1473 1520 1570 190
1000 1053 1099 1143 1190 1235 1282 1333 1389 1439 1493 1550 1600 1653 200
1050 1105 1154 1200 1250 1296 1346 1400 1458 1511 1567 1628 1680 1736 210
1100 1158 1209 1257 1310 1358 1410 1467 1528 1583 1642 1705 1760 1818 220
1150 1211 1264 1314 1369 1420 1474 1533 1597 1655 1716 1783 1840 1901 230
1200 1263 1319 1371 1429 1481 1538 1600 1667 1727 1791 1860 1920 1983 240

Spegel chargers have a type reference in terms of the number of battery cells to be charged and the initial value of the charging current (starting
current). For example, charger type S3P 36/95 indicates 36 cells and 95 A starting current, it. a 36-cell 500 A h battery will be charged in 8
h. Thus the correct size of charger will be determined by the number of cells, the ampere hour capacity and the time available for recharge