1942 - 1947 Chevrolet Shop Manual



	12-5

	when the battery is located elsewhere. Water level should be kept not more than 1/4" above the top of the plates in both passenger car and truck batteries at all times. To prevent over-filling, each battery cell is equipped with a non-overfill cell cap. This device consists of a lead sleeve in the cell opening which is threaded in its inner diameter for the filler cap. When the cap is screwed down into place, the lead sleeve is lifted and held in the upper position, uncovering the vent passage for the cell. This permits the gases to escape through the vent in the cap, as shown in Fig. 9. When the filler cap is removed for	greatly reduced. Never add acid to the battery. The specific gravity of a fully charged battery, as indicated by a hydrometer, should be between 1.275 and 1.300. The specific gravity of a fully discharged battery will be approximately 1.150. Keep the battery terminals clean, tight, and well covered with vaseline to prevent corrosion. To prevent freezing in cold weather, test the battery frequently and see that the specific gravity is kept up to at least 1.250. A discharged battery will freeze at a little below the freezing point of water. When batteries are removed from cars or trucks for charging, the battery is properly vented when the cell caps are screwed tightly in place. This note appears on each cap: "Keep Plug Tight While Charging." Where cell caps are left off batteries on the charging line to facilitate periodic checking of specific gravity, proper venting may be accomplished by lifting the lead sleeve in each cell opening and turning it clockwise or to the right so that the two tangs of the sleeve rest on the raised lip of the seat. Do not fill the battery with distilled water when the lead sleeve is in this position. Batteries in new cars and those carried in parts stock should receive regular attention in order to prevent sulphation of the plates due to inactivity of the battery. The following instructions are recommended for new cars and trucks, and batteries in parts stock: NEW CARS AND TRUCKS IN STOCK 1. Check battery electrolyte on each new car or truck received—add sufficient distilled water to bring the electrolyte up to not more than 1/4" above the top of the plates in each cell. 2. Check the electrolyte and add distilled water as necessary at weekly or semi-monthly intervals, depending upon the weather-warm weather causes greater water loss. 3. If the specific gravity of the battery is below 1.225, remove it and place on the charging line. Charge the battery until the specific gravity of the electrolyte reaches 1.275 to 1.300. Before a new car or truck is delivered to a customer, make sure the specific gravity of the battery electrolyte measures at least 1.260 -preferably higher. Under no circumstances should acid be added to a new battery to increase the specific gravity of the electrolyte.
	VENT HUG SCREWED INTO VALVE RAISES IT, PERMITTING AIR AND GAS TO ESCAPE. ALSO ALLOWS ADDED WATER TO COMBINE WITH ELECTROLYTE At THE CORRECT LEVEL

	Fig. 9-Battery Cell Cap in Position—Vent Open checking or filling a cell, the lead sleeve drops down by its own weight and covers the vent passage to the cell. The bottom of the sleeve is then within 1/4" above the top of the plates. Water can only be added to each cell until it reaches the bottom of the sleeve; air is then trapped in the expansion chamber of the cell because its vent is covered, Fig. 10, thus preventing any further entry of water to the cell. When the filler cap is installed, the cell vent is automatically opened as explained in the foregoing. Filling one cell does not fill all, so examine each one and fill as required. If inconvenient to obtain distilled water, use melted artificial ice or rain water and under no circumstances should ordinary water be used. Do not store water for batteries in metallic containers-use glass.
	TOP OF PLATES Ho. 10-Battery Cell Cap Removed-Vent Glased If the solution in a battery cell falls below a point where the plates are exposed, the plates become hardened and the battery capacity is