If you buy a set of batteries, you may sometimes wonder if you should buy a bigger package. After all, you may be unable to use them in time, especially if they have an expiration date. It makes sense, then, to wonder if batteries can go bad when you are not using them.
Yes, unused batteries go bad, meaning they lose their charge over time. The expiration date on a non-rechargeable battery is typically when only 80 percent of the original charge is left.
It’s good to know when you can expect your batteries to expire. This way, you can plan when you buy them in the first place so that you don’t buy more than you’ll be able to use before the expiration date.
Do Batteries Expire?
The simple answer is that, yes, unused batteries can go bad. But what exactly does it mean when a battery goes bad? Read on to find out!
What Does It Mean for a Battery to Go Bad?
When we talk about batteries going bad, we think about the expiration date, which is typically written on each battery.
However, a battery’s expiration differs from the expiration of a food product. It doesn’t start to smell or go rancid, but when it expires, it merely means that you can’t expect it to have a full life anymore. It may, but the manufacturer cannot guarantee that you can take full advantage of the original battery life after the expiration date.
The expiration date is the estimated date when the battery’s charge is only 80% of what it was initially. Batteries have a self-discharge rate, the speed at which they lose charge while you’re not using them.
Many people don’t know this, but batteries lose their charge immediately after they are made. Although this happens at a prolonged rate, the amount of discharge does become significant over time.
Some batteries have faster discharge rates than others. It varies based on the brand and type of battery. You can’t compare different batteries in this way since they operate using various chemical reactions in the battery’s interior.
However, even though the battery will eventually lose all its charge as it sits idle, it has not lost all its charge by the expiration date. On average, batteries will only have lost about 20% of their charge by this time.
This means that just because a battery happens to be past its expiration date, it does not mean you cannot use it. You will likely still be able to get a great deal of use out of it unless you have waited so long that it has completely self-discharged.
What Causes Batteries to Go Bad?
You might wonder what exactly it is that causes batteries to lose charge. The expiration date on a package of batteries depends on how long it will take for all of the energy inside the battery to be consumed. A chemical reaction inside the battery generates energy, causing the structure to consume energy even when you aren’t actively using it.
The nature of the battery is such that this chemical reaction is continuously going on, even when the battery is not currently powering a device. It will happen rapidly and consume more energy when the battery is used, but it happens no matter what.
The shelf life of a battery varies depending on the exact type and size. However, they become weaker over time, whether or not they are being used.
There are electrodes inside each battery. Essentially, these are strips of metal tape that are coated with a substance called an oxide (a compound that contains oxygen and another element). These strips are rolled up within the battery. Over time, parts of the battery will corrode, which leaves the battery with less charge or render it unusable.
For example, in a lithium battery, the lithium concentration in the cathode will go down over time because it will combine with the anode material. This chemical reaction is irreversible. However, as with any other battery, the storage conditions can significantly change. High humidity and temperatures can accelerate the chemical reactions contributing to the battery’s deterioration.
How Long Do Batteries Last?
There are a few different parameters that you can use to figure out how long batteries last. There is run time, cycle life, and shelf life. The answer also depends on the specific type of battery that you are using.
- Run time is how long a battery will last in a single usage. This will depend on the device since each device will consume a different amount of energy per unit of time (this parameter is referred to as a watt-hour). Also, devices sometimes consume more power when they are older. This does not apply to a battery that is in storage.
- The cycle life is how many complete charges and discharges can be done on a rechargeable battery before it no longer works. Even though a battery is rechargeable, it will only have a finite number of cycles.
- Shelf life is how long batteries will hold their charge while on the shelf, remaining unused. As you already know, the expiration date of a non-rechargeable battery is the date at which it is expected to have 80% of its original charge. From here, the battery will continue to self-discharge until it has no charge left. At this point, it has reached the end of its shelf life.
The definition of shelf life differs somewhat for rechargeable batteries; in this case, the shelf life is how long the battery pack can go unused without losing its charge before you have to recharge it completely.
The shelf life of a battery is affected by the temperature and humidity in the surroundings. Typically, the warmer and more humid the environment, the shorter the shelf life will be. Higher-quality batteries will have longer shelf lives as well.
Non-Rechargeable Batteries
Many different types of chemistry make up non-rechargeable batteries. This can have a significant effect on the shelf life of the battery.
Alkaline Batteries
This is the most common type of non-rechargeable battery. Typically, the shelf life of an alkaline battery is five to ten years at room temperature. Some people may attempt to charge an alkaline battery, but this is considered very unsafe, and most professionals would not recommend it.
Lithium Batteries
Most of the time, the shelf life of a lithium battery will be 10 to 12 years. However, the shelf life can vary widely based on different factors, such as chemical composition and the specific manufacturing process; sometimes, one of these batteries can last up to 20 years. It is recommended that you store these batteries at 70 degrees Fahrenheit.
Carbon-Zinc Batteries
Generally, carbon-zinc batteries are cheaper than alkaline batteries. However, they also have shorter shelf lives. Fairly recently, they were at a higher risk of leakage because of their thin walls. The shelf life of a carbon-zinc battery is typically three to five years.
Rechargeable Batteries
There are also many types of rechargeable batteries, and they can vary in shelf life and cycle life.
Nickel-Cadmium Batteries
These rechargeable batteries are one of the oldest types out there. They have many advantages, including longer shelf life and cycle life than other rechargeable batteries. They are also more able to retain performance quality in more extreme temperatures. However, they have less energy density and are more toxic to the environment than newer technologies.
The shelf life for a nickel-cadmium battery is typically between 18 and 36 months, and it can handle at least 1,000 charge-discharge cycles.
Nickel Metal Hydride Batteries
These batteries have a longer shelf life than nickel-cadmium batteries, but shorter cycle lives. The higher energy density of these batteries still gives them an advantage because you don’t have to charge them as often. Usually, they will last for about 700 to 1,000 cycles and have a shelf life of three to five years.
Lithium Rechargeable Batteries
There are many different types of lithium rechargeable batteries, with various chemical compounds that include lithium. Because of the other compounds that can make them up, the shelf life can vary significantly within this category. These batteries will generally provide you with between 600 and 1,000 life cycles. They usually have a shelf life of about two years.
Lead-Acid Batteries
There are multiple types of lead-acid batteries. They can vary widely in performance, shelf life, and cycle life. However, the average shelf life is about six months. These batteries can typically last for about 200 cycles.
Storage Tips to Maximize the Life of Batteries
There are a few things that you should do if you want to make your batteries last as long as possible.
Keep Batteries Out of Appliances
If you’re not currently using a battery-operated item, it’s a good idea not to keep the batteries inside them. Your batteries will likely last much longer if you take them out and store them in a separate location.
This is good for both your batteries and the items, as well. If the batteries corrode or leak while inside the items, the items could be damaged, in some cases, permanently.
Control Storage Temperatures
The temperature at which you store your batteries matters. You want to make sure to avoid both extreme heat and extreme cold. Many people think it’s a good idea to put batteries in the refrigerator or freezer, but condensation from the refrigerator can damage the battery and the frigid environment.
It would be best to put batteries in a dark, cool, and dry place. If you have to put them in a storage unit, you should make sure it is a climate-controlled facility.
Keep Them in Packages
When batteries come into contact with other metal objects, they are at higher risk of rupturing or leaking. To prevent this occurrence, it’s a good idea to store them in their original packaging. In this package, they will be protected from any outside agents.
If you’ve already thrown the package away or otherwise don’t have the option to keep it, try these storage alternatives:
- You can keep your batteries in a battery storage box.
- Tie your batteries with a rubber band and put them in a plastic bag. Be sure to place the batteries positive and negative ends opposite each other when tying them.
Don’t Mix Old Batteries with New Ones
If you only have one new battery, it might be tempting to put it into a device with an old one in the hopes that just one new one will be enough to power it. However, this is not a good idea. If you mix old and new batteries in the same device, you make battery leakage more likely. This can lead to damage to the entire device.
It’s always best to keep old and new batteries separate. It might be hard to know which batteries are fully charged, but a battery tester can help you with this. Another reason why it is good to keep them separate is that this way, you likely won’t end up losing power in a device unexpectedly.
Know a Little Bit About the Battery
As you know, there are non-rechargeable and rechargeable batteries. The ones that are rechargeable should be stored at a 40% charge. This allows the battery to discharge gradually so you can recharge it when needed.
Most batteries that people use for regular devices are non-rechargeable. However, it’s good to know the basics of non-rechargeable and rechargeable batteries in case you need to use a rechargeable battery at some point.
Never try to recharge a battery that is not labeled “rechargeable,” as this can be dangerous.
Know How to Take Care of Rechargeable Batteries
Most of the batteries people use are non-rechargeable; however, rechargeable batteries are pretty standard, particularly in the lithium-ion variety. Therefore, you should also be familiar with ways to maximize the lifespans of rechargeable batteries.
When you store rechargeable batteries, try to store them when they are as close as possible to 40% charged. It would be best if you didn’t allow them to become entirely depleted before storing them.
It’s also good to charge these batteries fully before you use them. This way, there will be less chance that you’ll have to unnecessarily put it back on the charger. Remember, each rechargeable battery has a cycle life, and you don’t want to take it on and off the charger more often than you must.
When the battery is fully charged, take it off the charger as soon as possible. If you leave it plugged in for a significant period, even after it has reached 10%, this can shorten your battery’s life.
Protect the Batteries
It’s also essential to preserve the batteries themselves. Some tips for storing your batteries include:
- Wherever you are storing them, make sure that the batteries aren’t at risk of being crushed or punctured. Keep them in a sturdy container where you know they will be safe.
- Ensure you don’t store batteries with other metal objects, such as loose change or paper clips. When batteries come into contact with other metal objects, even if they aren’t currently being used, they are at a higher risk of short-circuiting. This can then cause the batteries to leak, which damages the battery and releases battery acid that can be harmful to its surroundings and even to you.
- If you’re using 9V batteries, make sure not to remove the plastic caps until you’re using them. These caps are there for protective purposes.
Protect Your Valuables
Batteries can leak. This isn’t what we generally mean when we talk about batteries going bad, but it can happen and ruin the battery. When batteries leak acid, they can end up causing damage to other items in the surroundings. For this reason, it’s a good reason to make sure that when you store batteries, you not only make sure to store them in an environment that will preserve them, but you also store them away from other valuables.
Conclusion
Many people don’t think that much about batteries. After all, they have expiration dates, so people use those as a guide. If you start using a battery on its expiration date, you will usually be able to take advantage of 80% of its original charge. It’s good that you know this, so you know not to throw a battery away just because it has reached its expiration date.
To prolong the life of your batteries, keep the storage tips we mentioned in mind. This way, you don’t have to go out and buy new ones before it’s necessary.
You can also make sure that misuse of the batteries doesn’t end up destroying the devices they power or other valuable items. Just as with many things, understanding batteries and how to care for them can help you get better use.