How to Add Water to a Delco Battery

by Jody L. Campbell
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There are three kinds of Delco batteries. The more common ones today (especially in automotive batteries) are maintenance-free batteries. These are sealed batteries and require no maintenance whatsoever. Another kind is called the low-maintenance or hybrid battery. These require little maintenance, but on occasion, if the battery has been over-charged, you may have to add water to the cells. The last type of battery is the filler-cap batteries. While all batteries should require little maintenance, conditions can occur when the hybrid and filler-cap batteries should be visually inspected and maintained to achieve their longevity.

Step 1

Protect your hands and eyes with safety goggles and safety gloves before maintaining the Delco battery. The sulfuric dilute electrolyte will burn your skin, and if it contacts your eyes, blindness or serious injury can result.

Step 2

Visually inspect the battery housing for leaks, cracks or corrosion. The three main causes for batteries requiring maintenance are leaks or cracks in the housing, over-charging of the battery and the dilute evaporating or vibration.

Step 3

Inspect the battery hold-down device (if applicable) to ensure it is securing the battery in its cavity and tray. Correct by tightening the hold-down if necessary.

Step 4

Remove all the filler caps on the Delco battery in a well-lit area. Most of the caps unscrew counterclockwise from the individual cells. Loosen these with a pair of pliers and then remove them. Other types of filler caps may simply cover the cells. Use a screwdriver to gently pry these from the top of the battery housing.

Step 5

Inspect each cell to ensure the electrolyte dilute is not below the lead separators. If so, replace the battery.

Step 6

Add distilled water only, using a battery refractometer to siphon the water into the refractometer suction reservoir, and purge it into each cell requiring water. Do not overfill. The correct level is 1/2-inch above the separator, which will be about 1/8-inch below the fill ring.

Step 7

Wait a few seconds after adding water to the cells. This will allow the water to flow into other cells inside the battery and help prevent over-filling. If necessary, use the refractometer to suck out some of the dilute before replacing the cell caps. Since this solution is highly caustic, be sure to dispose of any dilute properly.

Step 8

Replace the cells caps when finished. Make sure the screw-type caps are tight, but not overtightened. You don't want to crack the plastic caps and cause a leak. Make sure the pop-in caps are seated properly to the top of the battery housing in the individual fill holes.

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