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.

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.

Battery 101: Equalizing Charges

A topic we receive regular questions about is equalizing charges – or the deliberate overcharging of a battery. Since there’s a lot of confusion about what it is, how it affects your battery type, how to do it, and when it should be done, we’ve compiled the basics of an equalizing charge. Let’s jump in.

What is an Equalizing Charge?

An equalizing charge is just another way of describing a deliberate overcharge of the battery, and is part of a proper maintenance routine that should be performed on lead acid batteries.

The purpose is to remove sulfate crystals from the battery plates. Over time the battery plates develop a sulfate coating – which is the number one cause of failure in lead acid batteries. Equalizing the battery also helps fight against stratification.

How Does it Work?

When a battery is given an equalizing charge, it is being overcharged in such a way as to remove (or blow off) the sulfate coating. This allows the surface area of the plates to interact fully with the electrolyte in the battery. It also helps with acid stratification. This is when the acid concentration is greater toward the bottom of the battery.

Stratification occurs over time as the heaviness of the acid causes separation from the water, creating an unequal mixture and reduction in capacity. The equalization charge process causes the electrolytes to bubble – which is great because it  mixes up the acid and creates a more even distribution.

When Should You Perform the Equalizing Charge?

For a 12 volt battery, you should charge it with a minimum voltage of 14.4 volts every 10 discharge cycles for at least one hour. This typically averages out to once per month. There are some manufacturers that suggest the equalization charge needs to only be carried out twice a year or as necessary.

A good rule of thumb is to gauge how often your battery is fully charged. A battery that regularly reaches a full charge will need an equalization charge less frequently compared to a battery that is not used as often. If you experience reduced battery performance, this is a good indication that you may need to give it an equalizing charge.

How Should You Perform an Equalizing Charge?

There are a few things you should keep in mind when equalizing your battery.

First and foremost, do not begin the process and then walk away. You should keep a close eye on the process. If the battery begins to overheat things could go bad – fast. As the battery heats up, hydrogen is emitted. This venting is normal but the hydrogen is very flammable.

If the room is not properly ventilated and the battery gets too hot, the hydrogen could explode. It’s a good idea to keep the room cool and ensure good ventilation before you get started. (Hydrogen only has to reach a concentration of 4% before it becomes explosive so it’s best to have the room properly set up before you start.)

Ok. Now that you’ve got the basics down, keep these pro tips in mind.

Pro Tips:

  • Don’t forget: make sure the battery is fully charged before you begin.
  • Disconnect loads: because you are overcharging the battery, you could damage any equipment that may still be connected.
  • Not all chargers have an equalizing charge setting. Make sure yours does before you begin – if you’re unsure, you can always ask us for help.
  • Check the specific gravity (SG) readings before you begin and then monitor them throughout the process.
  • Only begin equalization if the SG reading shows a difference of 0.030 between the cells.
  • End the charge when the SG reading stops rising.
  • Keep a close eye: monitor the battery temperature and do not allow the battery to become much hotter than 115 degrees Fahrenheit.
  • Patience is a virtue: depending on the amount of sulfation and the battery type, the process could take hours.

Giving your battery an equalizing charge is one of the best forms of maintenance you can do beyond the typical care of keeping the battery clean and storing it in a cool place.

This process can be tedious, time-consuming and, frankly, it can be a bit smelly. Only perform this process if you can do so in a safe manner and have the appropriate equipment. Proper maintenance of your batteries will not only maximize their longevity, but will also maximize their level of performance throughout their life cycle.

Battery 101: 3 Useful Facts On Lead Acid Batteries

The Three Most-Asked Questions

Our team here at Northeast Battery fields a ton of questions about batteries and how they work. While we get a range of questions for different battery applications, we thought we would go ahead and answer the three most commonly asked questions about lead acid batteries. Ready? Here we go.

  1. Do lead acid batteries develop a memory?

The quick and simple answer is, no. For those looking for extra credit, check out the below.

Lead acid batteries are not affected by the memory effect. The memory effect was limited to the nickel-cadmium batteries in the 70’s and 80’s. The memory effect was the occurrence when a nickel-cadmium battery would develop a cyclic memory that would allow the battery to “remember” how much energy was previously drawn.

During subsequent draws, the battery would not deliver more than it had before. Modern day nickel-cadmium batteries do not experience cyclic memory.

  1. Do lead acid batteries discharge when not in use?

All batteries experience some amount of self-discharge, yes. But, the rate of discharge for lead acid batteries depends on a few key factors.

  • Temperature: The warmer the environment while a battery is in storage, the faster the rate of self-discharge. For example, a battery being stored at an average temperature of 80℉ will discharge at a rate of 4% per week. Whereas a lead acid battery being stored at 65℉ will only discharge at a rate of approximately 3% per month.


  • Length of Storage: The amount of time a battery spends in storage will also lead to self-discharge. A lead acid battery left in storage at moderate temperatures has an estimated self-discharge rate of 5% per month. This rate increases as temperatures rise and as the risk of sulfation goes up.


  • Sulfating: This is a buildup of lead sulfate crystals and it occurs when a lead acid battery is left sitting without a full charge. Even if you are giving your battery a small charge such as putting it in the car and letting it idle, this is still not enough to combat the self-discharge that can take place.


  • Dirt: Dust and dirt on a stored battery can also create a reaction that leads to self-discharge. You can easily prevent this by wiping down the top of the battery with a clean, dry, and soft cloth. The best way to reduce the amount of self-discharge while your batteries are in storage is with the three C’s. Keep them clean, cool and fully charged.
  1. Do I need to completely discharge my lead acid battery before recharging it?

This is a hard and fast NO. By fully discharging your lead acid battery, or even discharging it below 80% of its rated capacity, you could damage the battery.

The belief that a battery needed to be fully discharged before recharging goes back to the memory effect issue. (See question 1.) Since that is no longer an issue (and never was an issue with lead acid batteries) there is not a need to fully discharge.

By discharging a lead acid battery to below the manufacturer’s stated end of life discharge voltage you are allowing the polarity of some of the weaker cells to become reversed. This causes permanent damage to those cells and prevents the battery from ever being recharged.


Battery 101: AGM vs. GEL Technology

The technology used to create batteries has come a long way since the time of glass cells and wooden encasements. Now we have specialized technology and advancements and it can get confusing trying to keep it all straight. So, we’d like to untangle some of this confusion by asking the question: What is the difference between AGM and GEL technology?

Before we dive feet first into the differences between the two, let’s take a look at what exactly each of them is.

AGM Batteries

AGM technology stands for Absorbent Glass Mat. That explanation alone sounds ridiculous but wait. The absorbent glass mat refers to a fine fiberglass mat that is capable of absorbing sulfuric acid, making batteries spill proof. Makes more sense now right? In the 1980’s the demand was increasing for lighter weight and less hazardous batteries that could be used in aircraft and vehicles.

AGM technology allowed this demand to be met. All of a sudden batteries could be transported without hazardous material issues and the construction of the mat meant that batteries could now be shaped as a cylinder or the traditional rectangular cube.

GEL Batteries

GEL technology is another matter altogether. A gel cell battery is a battery that uses a sulfuric acid that has been mixed with fumed silica to create a gel-like substance that is immobile. Because of the GEL cell, the battery does not have to be kept upright and the electrons can flow between the plates without the threat of spilling.

These batteries produce few fumes which make them ideal to be used in places that don’t have much ventilation.

Know that we have a better understanding of them, let’s compare ’em.

The Differences

While these batteries are not the same, some similarities cause people to confuse the two. They are both non-spillable, are deep cycle (meaning they can be deeply discharged), and can be transported safely among other things. So what sets them apart?

  • AGM

– Preferable when a burst of amps is required.

– Can last for years.

– Can be easily recharged, in some cases up to 5 times faster.

– Can be produced at a lower cost than gel batteries.

– Have a low internal resistance.

– Perform well in temperatures below 32 degrees.

  • GEL

– Lower power capacity.

– Does well in warmer environments.

– Does well with slow discharge rates.

– If recharged incorrectly the battery will fail before the end of its life cycle.

– Not suitable to be used as starter batteries because of an increased acid resistance.

– Do not perform well in below-freezing temperatures.

So when trying to decide which battery to purchase consider a few things.

  1. What application are you using the battery for?
  2. Will the battery have to function in below-freezing temperatures?
  3. How will you recharge the battery?
  4. Do you need a slow discharge rate or will you require bursts of power?

Once you have the answers to these questions you can determine the best battery for you. Warmer climate and lower discharge rates? Springing for the gel battery may just be the answer.

Colder climate and you want to use the battery as a starter battery? Definitely go for the AGM. Understanding the battery you are purchasing will go a long way in preventing damage to your equipment and preserving the life of the battery.