Battery 101: You, Water, and Your Battery

Water, or electrolytes, are a very important part of what makes your battery work. The amount of water in combination with the size of the battery plates is what determines the amount of charge your lead acid battery will store. Knowing how to properly manage the water levels in your battery can help ensure the life of your battery and help you avoid catastrophic battery failure.

The Basics

As the battery is recharged and electricity flows through the water, it is converted into its original gasses of hydrogen and oxygen. This gassing creates water loss and is the direct reason you need to replenish the water in the battery from time to time.

Highly flammable gasses are the reason a lot of battery casings are vented. Sealed cases actually allow the gasses to recombine into water which compensates for some water loss, but not all.

When to Replenish

The best way to know it’s time for a refill is to check your water levels. If the water level drops below the tops of the plates, you can damage the battery beyond repair. Follow these few rules of thumb:

  • Check the manufacturer’s recommendations. They will typically offer guidelines for your specific battery.
  • The more often you use and recharge the battery the more water loss you’ll experience, so adjust your maintenance schedule accordingly.
  • Temperature is a big factor when it comes to water loss. If you live in a warmer climate you’ll need to check your water levels more often. It’s also helpful to familiarize yourself on what causes battery leaks. 

The water level should be about a ½ inch above the tops of the plates to be considered in normal range. When adding more water, make sure you use distilled water. Tap water contains minerals that can diminish the performance of the battery and can increase the rate at which they self-discharge. You should also make sure that your battery is fully charged before adding water.


Pitfalls to Watch Out For

New Batteries can sometimes have low electrolyte levels. Make sure you charge the battery and then add more water if it’s necessary. If you add more water before the battery is fully charged you run the risk of electrolyte overflow.

Overwatering can cause the electrolytes to become diluted and you will experience a drop in performance levels. If the water levels are within a normal range, avoid topping it off.

Underwatering can lead to sulfation. Sulfation is when sulfate crystals begin to build up on the battery plates. Sulfation results in longer charging times, loss of power and is the number one cause of early failure.


Beware of Cutting Corners

Many people ask if they can reduce the need to add water to their battery if they reduce the charging voltage. While this is true, the lower the charging voltage the less water loss will be experienced, this process has other consequences. Battery stratification is the most common side effect of charging with a lower voltage.

Stratification is when the acid in the electrolyte begins to separate and settles at the bottom of the battery. This concentration of acid leads to sulfation, which is mentioned above, Sulfation is the enemy of your battery and proper maintenance should be adhered to if you wish to prolong the life and capability of your battery.