Battery 101: Most Common Lead Acid Battery Mistakes

Anytime you make a purchase, it’s best to understand the ins and outs of your new product. But, let’s be honest – sitting and reading through a manual or doing research isn’t always the top item on your to-do list. So, we narrowed down what you need to know here. If you’re new to lead acid batteries or just looking for better ways to maintain their performance, keep these four easy things in mind.

1. Undercharging

Undercharging occurs when the battery is not allowed to return to a full charge after it has been used. Easy enough, right? But if you do this continuously, or even just store the battery with a partial charge, it can cause sulfating. (Spoiler alert: sulfation is not good.)

Sulfation is the formation of lead sulfate on the battery plates, which diminishes the performance of the battery. Sulfation can also lead to early battery failure.

Pro tips:

  • The best way to prevent this from happening is to fully recharge the battery after use and before storing.
  • You should also top off the charge every few weeks if the battery will be stored for a long period of time.


2. Overcharging

While you certainly don’t want to keep your battery in an undercharged state, overcharging is just as bad. Continuous charging can:

  • cause corrosion of the positive battery plates
  • cause increased water consumption
  • even allow for excessive temperatures causing damage inside the battery.

This continuous heating from overcharging can destroy a battery in just a few short hours.

Pro tip: a good rule of thumb to help avoid the trap of overcharging is to make sure you charge your battery after each discharge of 50% of its total capacity.

If the battery will be stored for a month or more you should charge to full capacity before storing and then charge throughout the storage time. Every few weeks should be fine. You can also consider using a trickle charger.

A trickle charger is designed to charge your battery slowly over a period of time and not overcharge it. Some trickle chargers can be safely connected to the battery for a few days while others are designed to stay connected for a few months.


3. Underwatering

Because water is lost during the charging process, damage can occur if that water is not replenished.

If the electrolyte level drops below the tops of the plates, the damage can be irreparable. You should check your batteries’ water level frequently, and refill the cells with distilled water as needed. Under watering, the battery can cause sulfation that is irreversible.

Pro tip: the best way to avoid this is to refrain from overcharging and check your water levels. The more the battery is used and recharged, the more often you will need to check for electrolyte depletion.

Keep in mind, a hotter climate will also increase water depletion. Make sure the battery is fully charged before adding more water to the cells.


4. Overwatering

Not only can your battery have too little water to function properly, but it can also have too much. Overwatering can cause the electrolytes to become diluted, which results in diminished battery performance levels.

Pro tip: a normal fluid level is around ½ inch above the top of the plates or just below the bottom of the vent. If you check your fluid levels and the water level is sufficient, do not top it off.

Let’s do a quick myth buster: there is a common belief that lowering the charge voltage to 13 volts or lower will decrease the need to check the water levels as often.

While this is true, it can also lead to battery stratification – which causes the battery acid to separate from the electrolytes and collect at the bottom of the battery. This leads to sulfation which, as mentioned earlier, leads to decreased battery performance and a shortened life cycle.

So, what does this all mean?

The issues surrounding over and under charging as well as over and under watering can be a fine line to walk. It’s really just about finding the sweet spot.

Most battery manufacturers provide a list of guidelines that will make it easier to care for and maintain your lead acid battery. We know better than anyone that a ton of factors can go into maintaining the proper charge and the proper electrolyte levels. If you can only remember one, remember temperature — it’s one of the biggest factors.

  • The warmer the environment, the more often a stored battery needs a top off charge, as well as have its water levels checked.
  • The cooler the environment, the more time you can let pass between charges and water refills.

Checking out the manufacturer’s recommendations will go a long way in helping you prolong the life of your battery. If you need clarification or have any questions, give the NEB experts a call; we’re here to help, after all.