Chapter XI Electrical System
Great Wall Baoding Internal Combustion Engine
Manufacturing Company Limited
463
2. Preparing Electrolyte
2.1 Electrolyte Preparation Methods
(1) The lead-acid storage battery electrolyte is made of pure water and concentrated sulphuric acid. The
density of electrolyte used for starting an automobile is 1.280g/cm
3
±0. 005g/cm
3
(25°C).
(2) The container where electrolyte is prepared should be acid and heat resistant glazed ceramic, glass
jar, trough or leadwork torque. Operation staff should be equipped with protective appliance when
preparing electrolyte.
(3) Brush off the container and wash it with pure water before preparing electrolyte.
(4) Fill the pure water needed for preparing electrolyte into the container and then mix the concentrated
sulphuric acid into the pure water and keep stirring. It is forbidden to fill water into sulphuric acid because
it will cause burns as a result of spattering fluid.
Reduction formula d25 = dt + 0. 0007 (t-25)
In this formula: d25=the electrolyte density at 25°C; dt: the electrolyte density at temperature of t; 0.0007:
temperature factor; t: the electrolyte temperature practically measured.
The proportion of pure water (or distilled water) to the sulphuric acid in electrolyte is shown in Table
11-1-4.
Table 11-1-4 Proportion of pure water (or distilled water) to sulphuric acid in electrolyte
Electrolyte
specific gravity
at 20°C (g/cm
3
)
Volume ratio of
pure water (or
distilled water)
to sulphuric
acid
Mass ratio of
pure water (or
distilled water)
to sulphuric
acid
1. 10
9.80:1
6.28:1
1. 11
8.80:1
5.84:1
1. 12
8.00:1
5.40:1
1. 13
7.28:1
4.40:1
1. 14
6.68:1
3.98:1
1.15
6.15:1
3.63:1
1. 16
5.70:1
3.35:1
1. 17
5.30:1
3. 11:1
1. 18
4.95:1
2.90:1
1. 19
4.63:1
2.52:1
1.20
4.33:1
2.36:1
Electrolyte
specific gravity
at 20°C (g/cm
3
)
Volume ratio of
pure water (or
distilled water)
to sulphuric
acid
Mass ratio of
pure water (or
distilled water)
to sulphuric
acid
1.21
4.07:1
2.22:1
1.22
3.84:1
2.09:1
1.23
3.60:1
1.97:1
1.24
3.40:1
1.86:1
1.25
3.22:1
1.76:1
1.26
3.05:1
1.60:1
1.27
2.80:1
1.57:1
1.28
2.75:1
1.49:1
1.29
2.60:1
1.41:1
1.30
2.47:1
1.34:1
Note: The table values are calculated on a specific gravity of 1.83 of pure sulphuric acid at 20°C.
