Chevrolet 10 Series 1970 Service Manual page 396

ENGINE-ELECTRICAL 6Y-4
F ig . 6 b —C h a rg in g Lead A dapters
w here a liv e circu it is broken. C are must always
be taken when connecting or disconnecting b ooster
leads or cable clam ps on fast chargers- P o o r con­
nections are a common cause o f e le c tr ic a l arcs
which cause explosions.
BATTERY C H A R G IN G
B e fo re charging a battery, the ele c tro ly te le v e l must
be checked and adjusted i f needed.
B attery charging consists o f applying a charge rate
in a m p eres fo r a p erio d o f tim e in hours.
10-am pere charge rate fo r
a m pere-hou r (A .H .) charging input to the battery.
Charging rates in the three to 50 am pere range are
g en e ra lly satisfactory. No p articu lar charge rate or tim e
can be sp ecified fo r a battery due to the follow ing factors:
1. The s ize , or e le c tric a l capacity in am pere-hou rs
(A .H .), o f the battery.
Example: A com pletely discharged 70 A.H . bat­
te ry req u ires alm ost tw ice the recharging as a
40 A.H . battery.
2. Tem p eratu re o f the b attery elec tro lyte.
Exam ple: About two
needed to charge a 0°F. battery than an 80°F.
battery.
3. B attery sta te-o f-c h a rge at the start of the charging
p eriod .
Exam ple: A com pletely discharged battery r e ­
qu ires tw ice as much charge in am pere-hou rs
as a on e-h alf charged battery.
4. B attery age and condition.
Exam ple: A battery that has been subjected to
Thus, a
seven hours would be a 70
hours l o n g e r w ill be
DO NOT SUCK
IN TOO MUCH
ELECTROLYTE
FLOAT MUST
BE FREE
F ig . 7 b —Testing S p e c ific G ra v ity
sev e re s e rv ic e w ill requ ire up to 50% m ore
am pere-hou r charging input than a re la tiv e ly
new battery.
The follow ing basic rule applies to any battery charging
situation:
" Any battery may be charged at any rate in am peres
fo r as long as spewing o f ele c tro ly te due to violen t ga s­
sing does not occur, and
tem peratu re does not exceed 125°F. If spewing o f e le c ­
tro ly te occurs, o r if ele c tro ly te tem peratu re exceeds
125°F., the charging rate in am peres must be reduced or
tem p o ra rily halted to avoid damage to the battery.
The battery is fully charged when o v e r a two-hour
p eriod at a low charging rate in a m peres a ll c e lls a re
gassing fr e e ly (not spewing liquid e le c tr o ly te ), and no
change in sp ecific g ra vity
sp ecific g ra vity is 1.260-1.280, co rre c te d fo r e le c tr o ­
lyte tem peratu re with the ele c tro ly te le v e l at the split
ring, unless electro ly te loss has occu rred due to age or
o v e r fillin g in which case the sp ecific g ra v ity reading w ill
be low er. F or the m ost sa tisfa ctory charging, the low er
charging ra tes in am peres a re recom m ended.
If a fter prolonged charging a sp ecific g ra v ity of at
lea st 1.230 on all c e lls cannot be reached, the battery is
not in an optimum condition and w ill not provid e optimum
perform an ce; how ever, it may continue to p rovide addi­
tional s e rv ic e if it has perfo rm ed s a tisfa cto rily in the
past.
An " em ergency boost ch a rg e/ ' consisting o f a high
charging rate fo r a short period o f tim e, may be applied
as a tem porary expedient in o rd er to crank an engine.
H ow ever, this procedure
battery r e s e r v e to crank a second and third tim e. T h e re ­
fo re , the " em ergen cy boost ch arge" must be follow ed by
a subsequent charging p erio d o f sufficient duration to
re s to re the battery to a sa tisfa ctory
R e fe r to the charging guide in this section.
When out o f the veh icle, the battery w ill req u ire adap­
te r s fo r the term in als to p rovid e a place fo r attachment
o f the charging leads.
HOLD
TUBE
VERTICAL
TAKE READING
AT EYE LEVEL
fo r as long as e lectro ly te
occu rs. The full charge
usually supplies insufficient
state o f charge.
CHEVROLET TRUCK SERVICE MANUAL