Adding Water For Batteries (distilled water). It is not as straightforward as it sounds. You may ruin a lead acid battery if you perform this guide improperly.
- See if your battery is dusty or dirty and use a dishcloth to clean without water. An air compressor will come in mighty handy to get rid of any dust so it will not mix with the water you are going to use, especially the dust around important battery regions like the acid vent cavities (aka cells).
- Note: some batteries have translucent sides that let you observe how much acid is currently inside each cell.
- Take the vent caps off using the flat head of, say, a screwdriver or another ideal tool.
- Use a clean rag to wipe the dust that might have accumulated hereabouts. You do not want dust to go into the vents and make for an inefficient acid mix; it is not a safety concern merely a cleanliness one. Just wipe the dust away from the holes and then swipe it off along the sides or margins of the cap region.
- Wear protective gloves while you work because you are dealing with strong battery acid.
- Repeat the above process for all six or so cells.
- Even out the liquid levels in each cell with sufficient distilled water. Leave enough room for the bubbling process. Do not fill each cell to the brim.
- Leave the caps off and in keeping with the ‘no dust’ rule, refrain from doing any project work that may send dust or debris up into the air; assuming you are doing this in a garage, workshop, or some such place.
- Attach the battery charger, hook up the terminals to the battery in question, and turn on the charger. The voltage, as you will observe, will go up then gradually descend. This is normal.
- The distilled water will bubble when the battery attains full charge and might overflow; this is why you left space in each cell. Let the charging continue for about an hour or more; never overnight or all day if it is charging at 10 amps.
A faulty battery will not start a vehicle properly. This is when a lead acid battery is fully depleted. It might come to life with a jump start but then revert to showing problems. Distilled water helps the battery hold voltage properly so it will most probably not discharge soon.