WATER LEVEL GUIDE
START WITH SAFETY
To get started, make sure to wear personal protective equipment such as protective eyewear and gloves when working on batteries.
WHEN TO ADD WATER
Conventional batteries contain a liquid “electrolyte” mixture of sulfuric acid and distilled water. The plates in a lead battery contain an active material that should be continuously bathed in electrolytes for proper operation, safety, and long life. A battery should only be watered after it is completely charged. But, you should always check the water level before charging. Before charging, make sure there is just enough water to cover any exposed plates (rectangular metal parts visible when you look inside a battery). After charging, add enough water to bring the level to the bottom of the vent, about ¾ below the top of the cell. Important note: that battery owners should never add sulfuric acid to their battery. During normal operation batteries will only consume water – and not sulfuric acid. When your battery’s electrolyte is observed to be low, filling the battery with water will keep the battery healthy and safe for use.
DON’T OVERWATER
While a battery is charging, the density of the electrolyte solution will increase. If too much water was added before charging, the electrolyte will expand and cause the battery to overflow and damage the battery. Additionally, excessive battery watering can result in additional dilution of the electrolyte, resulting in reduced battery performance.
“HOW OFTEN SHOULD I WATER MY BATTERY?”
How often you add water to your battery will depend on how often you use it. A golf cart battery that is only used on the weekends may only require once a month watering. A forklift used all day, every day, may need to have its battery watered every week. Hot weather also increases the need for watering. It’s important to check your battery’s fluid level regularly – and the best practice is to do so after the battery is finished charging.
AVOID TAP WATER
Tap water contains minerals that are harmful to batteries, even if added in small amounts. That's why distilled water is your best bet. It’s inexpensive, available everyone, and much cheaper than replacing a failed battery. Remember, that water will sit on top of the acid solution in your battery until it is mixed by the bubbling produced by charging. If you are taking hydrometer readings of the electrolyte, take readings it’s best to take them after charging is complete.
