Battery 101: Do Cement Floors Ruin Car Batteries?

You may have been told to never put a car battery directly on the floor of the garage because the cement will cause the battery to leak or loose its charge.

…Is this really true? Knowing what we do about batteries and cement it just doesn’t make sense. Or does it? (Fear not – we know the answer.) Let’s explore the myth of car batteries and the garage floor.

Early Car Batteries

If we take a look back at some of the earliest car batteries we will find that they were lead-acid batteries that had glass cells all encased in a wooden box. This means that if they were left on concrete or cement floors, the moisture from the floor could cause the wooden box to wrap, allowing the glass cells to shift and break.

Of course, the battery acid would leak all over the floor and the battery would be rendered useless. Not great.


As the construction of the car battery evolved into a nickel-iron battery encased in steel, and then even further with a hard rubber casing, the issue of breaking glass went away – but not the problem with discharging or “leaking”.

The rubber was porous and often contained carbon. The battery shell would take on the moisture of the floor, as with the wooden encasement, creating an electrical current between the battery cells causing them to discharge. Still not great.

Modern Day Batteries

Brands like Trojan and Odyssey are working overtime to continue to innovate battery design to make battery performance and storage better than ever.

The design of modern day batteries includes a hard plastic shell that eliminates the intake of moisture, thus making the garage floor a great place to put your car battery.

Cement and concrete floors provide a fairly good barrier between the car battery and extreme temperature changes that could otherwise cause damage to the battery cells allowing for a discharge leak.

What Does Cause Battery Leaks?

While the garage floor may not be the culprit anymore for leaky batteries there are a few ways your stored batteries can lose their shelf life.

  • Dirt and dust can become carbonized, creating electrical conduction which drains the battery. Combat this by using a clean rag to clean wipe off the tops of the battery.
  • Self-discharge occurs over time with lead-acid batteries. Reactions within the plates happen as the battery ages creating a leak. The warmer the air surrounding the battery the faster the rate of discharge. Keeping the air around stored batteries cool will help slow the rate of self-discharge.
  • While cold temperatures are rarely the cause of battery malfunctions, a battery that is at a low state of charged and exposed to freezing temperatures can freeze causing the case to crack. Keeping your battery fully charged during the winter months is an easy way to prevent this from happening.
  • Knowing the shelf life of your battery can help a lot as well. A car battery stored in a cool and dry place can last a few years if you keep it topped off with a trickle charger.

Today’s batteries are well insulated and no longer take on water that can cause discharging or leaking. That being said, there are clearly right ways and wrong ways when it comes to battery storage. Keeping your batteries clean, dry and understanding their shelf life can make a big difference in preserving their longevity and the quality of their performance. So go ahead and leave that battery on the cool dry floor of your garage. Kinda great, right?

Battery 101: Batteries, Defined

Batteries make stuff work – that’s what most people understand about batteries and how they work. But since the invention of the battery, scientists and engineers have not only developed better batteries (like AGM batteries), but have also created life changing machines that are dependent upon them.

To kickstart your battery education, check out some of the most basic battery terms.

Primary vs. Secondary Batteries

There are essentially two types of batteries, those that can be recharged and those that cannot.

  • Primary Battery: a primary battery is made up of primary cells that cannot be recharged, however, they have a lifespan that is measured in years.
  • Secondary Battery: a secondary battery is made up of storage cells that, once discharged, can be restored, or recharged. These batteries usually need to be recharged within a matter of months.

Primary batteries typically have a higher capacity than a secondary battery, but once it’s charge is spent, it must be replaced. Secondary batteries are gaining in popularity through their use in electric cars where it’s necessary to recharge regularly rather than replace.

Trickle Charging

Trickle charging is a method that is used with secondary batteries to help maintain their charge. This typically occurs through connecting the battery to a constant-current supply that will maintain the battery at a full charge.


In the world of batteries, voltage is a big word that encompasses quite a few different meanings. Let’s break it down just a little.

  • Voltage: loosely defined, voltage is the pressure from a power source, such as a battery, that pushes charged electrons through a loop, creating an electrical circuit.
  • Open Circuit Voltage is the voltage measurement when the circuit is open or not drawing a load.
  • Closed Circuit Voltage is the voltage measurement when the circuit is closed or is drawing a load.
  • Nominal Voltage is the operating voltage for a particular circuit or battery system when fully charged.
  • Cut-off Voltage (also known as end-point voltage) is the voltage level at which the connected equipment will no longer operate or is unsafe to attempt operation.

Why is this important? Simply put, the greater the voltage, the greater the flow of electrons producing more power.

Charge Capacity

The charge capacity also referred to simply as capacity, is the measurement of amp hours that can be withdrawn from a battery under a set of specific conditions. All other factors being equal, a battery with a higher capacity will have a longer runtime. Some factors that can affect the capacity of a battery are cut-off voltage, temperature, and discharge rate.

Discharge Rate

Discharge is the conversion process that changes the chemical energy of the battery into electric energy. There are different levels of discharge.

  • High Discharge Rate is the withdrawal of large currents for a short period of time. High discharge rates typically deplete the battery within an hour.
  • Low Discharge Rate is the withdrawal of small currents for longer intervals. This allows for battery usage in excess of an hour.
  • Deep Discharge allows for withdrawal of electrical energy to the cut-off voltage before requiring recharging.

While this is far from everything worth knowing about batteries, it’s definitely a good place to start.