Shelf Life of Alkaline Batteries

Alkaline Batteries

Shelf Life of Alkaline Batteries

What Is the Shelf Life of an Alkaline Battery?

Consumers use alkaline batteries for several products in their home, such as electronic toys, radios, clocks, smoke detectors and television remote controls. If you keep a stock of batteries available, it may help to know their shelf life.

Function

• The purpose of an alkaline battery is to power electronic devices until the charge within the battery runs out.

Composition

• Alkaline batteries, also known as dry cell batteries, have a steel outer casing. Fabric inside the core separates the electrodes from the anodes. The electrolyte is a potassium hydroxide solution in water that carries the ions within the battery cell.

Process

• Alkaline batteries produce power through a chemical reaction that begins to occur when you put the battery in a device, complete the circuit and combine the electrodes and anodes. The battery produces electrical energy because the battery contains the chemical reaction.

Shelf Life

• While an alkaline battery is reliable, it has a shelf life of about 7 to 10 years. Around that time, the chemicals within the battery become stagnant and no longer produce a chemical reaction to power the battery.

Considerations

• Some people believe that placing unused batteries in a freezer extends their shelf life. While the chemical reaction within an alkaline battery does slow at lower temperatures when in a device, there is no documentation available to support the assumption that a disconnected battery has a longer shelf life when kept cold.
• Alkalines major advantages (compared to the zinc-carbon battery system) are a high energy density; the ability to operate continuously at relatively high discharge rates over a wide temperature range (due to its lower internal resistance); and a shelf life in excess of four years. The cost of the alkaline battery, on a service life basis, is lowest in medium to high drain applications.
  
  CHEMISTRY
  The components of the alkaline-manganese battery are a zinc anode, a manganese dioxide cathode, and a highly conductive potassium hydroxide electrolyte.
  
  PERFORMANCE CHARACTERISTICS
  Voltage
  The open circuit voltage ranges from 1.5 to 1 .6V, depending on cathode formulation. Typical median operating voltage ranges from 1.3 to 1.1V under moderate discharge conditions.
  
  Discharge Characteristics
  Moderately sloping discharge curve.
  
  Energy Density
  75 Wh/lb. (163 Wh/kg); 6.5 Wh/in.3 (398 Wh/l).
  
  Effect of Discharge Load and Temperature
  Capable of performance at high discharge rates; typical temperature range: -4°F to 130°F (-20°C to 54°C).
  
  Shelf Life
  Up to 85% capacity remaining after 4 years of storage at 70°F (21°C).

By Michelle L Crame, eHow Contributor

January 21, 2010

MN1300 Alkaline Batteries

MN1300 Alkaline Batteries

Alkaline Batteries are all over the place: in our cars, our PCs, laptops, portable MP3 players and cell phones. A battery is essentially a can full of chemicals that produce electrons. Chemical reactions that produce electrons are called electrochemical reactions.

If you look at any battery, you'll notice that it has two terminals. Electrons collect on the negative terminal of the battery. If you connect a wire between the negative and positive terminals, the electrons will flow from the negative to the positive terminal as fast as they can. Normally, you connect some type of load to the battery using the wire. Inside the battery itself, a chemical reaction produces the electrons. The speed of electron production by this chemical reaction (the battery's internal resistance) controls how many electrons can flow between the terminals. Normal batteries have generally 1.5V per cell voltage (except some Lithium cells which have 3V voltage). The batteries which have higher voltage output are built generally from many 1.5V cells in series all put inside same "case". Since there are no real industry standards, many terms used by battery manufacturers have become misleading marketing hype.

Although the terms battery and cell are often used interchangeably cells are the building blocks of which batteries are constructed. Batteries consist of one or more cells that are electrically connected.The world of batteries divides into two major classes: primary and secondary batteries. Primary batteries such as the common flashlight battery are used once and replaced. The chemical reactions that supply current in them are irreversible. Secondary batteries (for example, car batteries) can be recharged and reused. They use reversible chemical reactions. By reversing the flow of electricity i.e. putting current in rather than taking it out, the chemical reactions are reversed to restore active material that had been depleted. Secondary batteries are also known as rechargeable batteries, storage batteries or accumulators.

As a battery is used, the amperage is consumed and the voltage drops. There is a formula for a ballpark estimate for battery life:
Estimated total battery life = (Ib / Id) x 0.7
Where: Ib = Total Capacity Rating of battery (mAh) and Id = Current Consumption of the device in milliamps (mA)
Use of this formula does not guarantee that you will get the determined battery life. Other factors such as weather condition (temperature, humidity, etc.), and battery condition can extend/shorten the battery life. This formula cannot be used to calculate battery life for alkalines. Battery state can be somewhat determined with the battery voltage. Please note that batteries do not show their correct voltage unless under a load. Battery testers are designed to provide this load; however, when testing batteries with a multimeter, you must have the meter set to measure DC voltage and place the battery under load by using a resistor in parallel with the test leads of the meter. How the battery voltage drops during the use varies from battery type to another.

Alkaline batteries are single-use batteries, but provide a higher start voltage and longer life than many other single use batteries. The capacity rating for alkaline batteries is not a fixed number on alkaline batteries, although it can be safely assumed that an alkaline battery will last significantly longer (2-3 times as long) as a same-size rechargeable under the same conditions. Alkalines do not have a fixed capacity rating because where the discharge rate of rechargeable batteries is a straight line, the discharge rate for alkalines slopes depending on the current drain. The higher the current drain, the faster the battery discharges. In alkaline batteries, the sloping discharge curve makes it impossible to accurately provide a mAh rating; the rating would vary depending on discharge rate and temperature. Alkaline batteries are significantly heavier than many other battery types for the same size, but they can store lots of energy (few times more than "regular" batteries). Alkaline batteries can take storage nicely when not used. Alkaline batteries stored at "room temperature" self discharge at a rate of less than two percent per year. However, if alkaline batteries are stored at higher temperatures they will start to lose capacity much quicker. At 85 degrees F they only lose about 5% per year, but at 100 degrees they lose 25% per year.

There is a variation of alkaline cell that can be charged with a limited number of times: Rayovac sells rechargable akaline batteries. Rechargeable alkalines are really just normal alkalines with a beefy casing to reduce leakage, but the full charge drops off significantly even after the first recharge cycle and gets worse from there.

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MN1500 Alkaline batteries

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Alkaline cells have an impressive energy capacity, usually
greater then 2500mAh. But this is only one of several factors that affects
the performance of a cell. At certain points in their operation Digicams
have extremely high power demands. The power a cell or battery can deliver
depends on both the voltage it can provide, and the electrical current it
can deliver (the power supplied is actually the voltage multiplied by the
current). The voltage is limited, it is fixed by the chemistry of the cell,
so the only way to deliver that power is with a large current. The
essential problem with alkaline batteries is that they have great difficulty
providing these large electric currents.

Alkaline cells are brilliant, however, in the right application. For low
power devices, or devices that are used infrequently e.g. doorbells, radios,
remote controls etc., they are superb. They have a huge energy capacity,
and a shelf-life of several years. . (Many
pro-photographers keep some high quality alkalines in their bag so that they
can always take a few shots if their rechargeables run out etc.)

Should you Recharge Alkaline Batteries

"Other types of batteries may burst causing injury to persons and damage," cautions your typical battery charger. It's a pretty serious warning that we unquestioningly follow. Disposable alkaline batteries and rechargeable nickel-metal hydride cells (NiMH) use different chemicals, so it makes sense that we can't just interchange our batteries. Seems straightforward enough, right?

So how, then, how are battery charger manufacturers able to market chargers that allow you to safely charge alkaline batteries? By carefully monitoring the charging process and building in intelligent sensors for preventing overcharging and over heating.

What makes a rechargeable battery rechargeable? The process is well explained in a Scientific American article: "One of the necessary conditions for a battery to be rechargeable is that the underlying chemical changes that occur during an electrical discharge from the cell must be efficiently reversed when an opposite electrical potential is applied across the cell." It must then be able to sustain this process efficiently and safely over many charging cycles for a battery to be labeled rechargeable.

While your typical alkaline battery has a reversible chemical process it performs more poorly with each charge. "In the case of the non rechargeable battery," writes Frank McLarnon in Scientific American, "when one attempts to recharge the battery by reversing the direction of electron current flow, at least one of the electrochemical oxidation-reduction reactions is not reversible." The result is a loss in charge and this assumes that a buildup of hydrogen gas in the reverse process hasn't caused the battery to rupture.

Even if it works, is it worth it? Perhaps not. The batteries being recharged should have been manufactured at the same time and, because they use different chemical compositions, batteries of different brands should not be mixed. The loss nature of the process might be frustrating as the life of the battery decreases unpredictably.

Its utility depends on how many alkaline batteries you have laying around to use with the $46 device. You're probably better off just gathering up your old AAs, taking them to be recycled and replacing them with NiMH rechargeables.

How to calculate battery capacity.

Alkaline Battery Capacity Measurement

Here’s some basic information on different types of batteries in general. This is not intended to be technical but an introduction to different types of battery to those who may not be technically inclined.

To help understand basic concept of circuitry, imagine a highway. Along the path of this highway lies a drawbridge. This drawbridge is a switch. when the bridge is open, the flow of traffic is halted. The total number of our cars has not changed, but the flow of those cars has ceased. Voltage then is represented by the number of cars on our fictional highway. By definition, voltage is the potential for electricity to do work. The cars will represent electrons -- which are the workers of the circuit. When our drawbridge closes, this potential is released and the cars are able to flow to the other side of the drawbridge to their final destinations. The measure of voltage is the volt (V).

When our cars begin to flow to their destinations, the volume of cars in a given space at a given time and the speed at which they flow represents current. Current is the measure of the flow of electrons. Our cars must also have somewhere to go before they begin to flow. In a circuit, electrons must have a path to follow, a complete loop, before they are able to flow and do work. Current is measured in amperes, or amps for short (A). Again, the total number of cars on the highway represents our voltage, and the number of cars at one point along with the speed of those cars represents current in the circuit.

Current Capacity Batteries are rated according to voltage and current capacity (ampere-hours). Each battery is composed of one or more cells. In our traffic analogy, these cells are representative of parking garages for our cards, or electrons. When the battery is hooked into a circuit, the cars have a path on which to travel. They then begin to flow and the circuit has current. When all of the cars have left the garage and run out of gas, the battery is dead and the current flow ceases. Current capacity is the approximate gas mileage of our cars. The voltage of a battery is determined by the chemical composition of the material within the cells. Just as diesel fuel and gasoline both have the capacity to do work within our cars, the different chemical compositions have capabilities of doing work similar to one another. mA x hours = mAH (current capacity) The current capacity measures how quickly a battery will discharge under certain circumstances. This figure is determined by multiplying the flow of the current from the battery into the circuit by the amount of time the battery is able to provide that current. So, Time = mAH/mA If you are given the current capacity of a battery (in mAH), dividing this number by the current requirement of the circuit will give you the time of the battery will last under a constant load. Let’s take, for example, a 9.6 volt battery rated at 1500 mAH (milliampere-hours) at 250 milliamps. By dividing 1500 mAh by 250 mA, we find the battery will discharge in about six hours. 1500 mAh ÷ 250 mA = 6 hours In contrast, the battery might be rated at 1250 mAh if used in a circuit requiring 500 mA. In this case, the battery would discharge in about 2.5 hours. 1250 mAh ÷ 500 mA = 2.5 hours It is this concept that makes predicting the usable time of camcorder batteries difficult. Camcorders require a great deal of current, especially when using certain features, such as auto-focusing, fast forward, or rewind. Each of these features requires a different amount of current. This factor alone makes the usable time difficult to predict. However, other factors must be taken into consideration, such as temperature. Therefore, a 2000 mAh battery will not necessarily last twice as long as a 1000 mAh battery -- although it will typically be close. Alkaline cells, regardless of their size, produce 1.5 volts. So, the parking garages may only hold a certain number of cars (remember, the TOTAL number of cars is voltage). Therefore, a “D” battery is composed of one alkaline cell. Conversely, a 9-volt battery is composed of six alkaline cells wire together in series. To explain this, we will deviate slightly from our traffic scene to a nearby railroad. Hooking batteries or cells in series is just like using multiple locomotives to pull cargo on a railroad -- the train is able to utilize the cumulative power of all of the engines to pull the railroad cars. Voltage Discharge Curve The voltage discharge curve is a vital tool to help you determine the appropriate type of battery to sell. This factor is determined by the chemical properties of the battery. Certain batteries exhibit what is known as a sloped curve. In this type of battery, the voltage gradually degrades as the battery gets older. Batteries exhibiting flat voltage curves maintain their voltage at a somewhat constant level until the end of their life, where the voltage suddenly drops off. In the graph at left, the top curve represents a flat discharge curve, the bottom curve represents a sloped discharge curve. Alkaline Batteries The most popular battery composition is alkaline. Alkaline batteries have a sloped discharge curve. Their voltage gradually drops off over the life of the battery until eventually, the battery is no longer usable. Although the discharge curve is sloped, it is still flatter than zinc-chloride and carbon batteries. Alkaline batteries can deliver up to 80% of their original capacity after being stored for four years. This makes alkaline batteries ideal for emergency devices such as flashlights, radios, and TVs. Alkaline batteries are 8 to 10 times more powerful than the zinc-chloride or zinc-carbon batteries. They’re very good for use in high-current applications, such as motorized toys and portable TVs. Since they are able to emit large amounts of current for short periods of time without significant voltage loss, alkaline batteries are also ideal for photo flash units. Watch this great video for a better understanding.

by EEVblog.com

Disposable Batteries

Disposable Batteries

Disposable Waste Batteries

Micro-mercury batteries do not pollute the environment.

Waste batteries for containing environmentally harmful substances become the consensus of used batteries in the end do not need to be focused, specialized recycling? Journalists interviewed for this purpose in China Battery Industry Association.

Chou, vice president of the association told reporters that, due to a wide range of batteries can not be generalized. At present, in the Chinese market, disposable batteries or alkaline manganese batteries (commonly known as alkali-manganese batteries or alkaline batteries) as long as the regular manufacturers, non-counterfeit batteries have been prescribed as “low mercury” or “mercury-free” batteries of such cells have no need for a separate collection, classification, focus, and direct and general domestic waste landfill with little or no hazard to the environment. If some cities in the establishment of a dedicated waste battery recycling center, you can focus on promoting the reuse of resources in reducing the production costs of a new battery is still useful. Vice-chairman Zhou told reporters at the same time, and now there is no harm to the environment is only a one-time Battery, a number of other types of batteries such as rechargeable batteries need a special recovery to ensure their non-pollute the environment.

Zhou, deputy director, said the reason why the battery can be disposable garbage recycling together, because by the end of 1997 the State Council on the nine ministries and commissions jointly issued a “limited battery products on the mercury rule”, since 2001 one of its provisions On 1 day ban mercury in the domestic production of various types of battery weight is greater than 0.025% of the cells; since January 1, 2005, the ban in the domestic production of mercury batteries is greater than the weight of 0.0001% of the alkaline manganese batteries; since 2006 years, starting January 1, prohibits domestic distribution of mercury is greater than the battery weight of 0.0001% of the alkaline-manganese battery. In other words, according to this standard production of disposable batteries, which have low mercury content will not damage the environment, the degree of pollution.

Learned through interviews with reporters for the issue of waste battery recycling, the Shenzhen Municipal Environmental Protection Bureau of Solid Waste Management Department, the staff’s allegations and Battery Industry Association, the staff say exactly the same. Department staff told reporters that because of Shenzhen landfill facilities, space is limited, one-off used batteries for recycling, to promote the lives of citizens and the general rubbish can be put together. “For hazardous waste, such as the class of non-disposable batteries, Shenzhen now has qualified enterprises specialized division to handle. If the basic sound of the disposable batteries collected and sent to our address, but taking up the limited human resources and Landfill site. a few years before the collection of a large number of disposable batteries, we have conducted a focus on landfill in the last year, handling, collection of used batteries to promote environmental protection activities in the last year, no longer held in the future will no longer be held. ”

How treatment of other waste electronic products

Disposable batteries are no longer on the need for specialized waste recycling, to address this issue, the reporter interviewed some members of the public. Almost all of the respondents do not know “on the restriction of the provisions of mercury batteries,” it was not clear disposable batteries do not need a dedicated recovered.

Her answer is that for a long period of time that the battery will pollute the environment should not throw, so a box at home, specially prepared to collect disposable batteries, because the outside is not easy to find recycling bins, so we have save the. Too many of our colleagues.

After listening to Chen after the reporter’s description of a sense of relief, but she believes that it produced a one-time battery technology is harmless clearance, but around there more and more electronic products, while their knowledge in this field very limited understanding of the hope in this regard the handling of waste dangerous goods, the Government has to give citizens lots guidance with Batteries. “Battery problem seems solved, but the scrap computer, scrap mobile phones? Plenty of time, we really do not know where to place them!”

Posted on February 3rd, 2010 in battery tip

Store Batteries in the Freezer to Retain Charge Longer

Store Batteries in the Freezer to Retain Charge Longer

Storing batteries at freezing or near freezing temperatures will greatly extend the amount of time they hold a charge, but only for some kinds of batteries. Read on to see which batteries don’t need the meat locker treatment and which benefit.

Over at The Huffington Post, they highlight several unusual things they’ve put in freezers for some benefit. It turns out that not all batteries benefit from the cold however:

A number of studies have shown that storing batteries in the freezer helps them retain their charge longer. This is less true for alkaline batteries (freezing extends their shelf life by only about 5%) than it is for NiMH and Nicad batteries often used in electronics. Keeping NiMH batteries in the freezer can boost battery life by 90%.

Alkaline batteries stored at “room temperature” self discharge at a rate of less than two percent per year. So normally refrigerating or freezing them will only help maintain their energy by a tiny amount. Hardly worth the effort of chilling them. However, if alkaline batteries are stored at higher temperatures they will start to lose capacity much quicker. At 85 degrees F they only lose about 5% per year, but at 100 degrees they lose 25% per year. So if you live in a very hot climate or are storing your alkaline batteries in a very hot location, it may be worthwhile for you to store your alkaline batteries in a refrigerator instead.

NiMH and NiCd batteries self discharge at a MUCH faster rate than alkaline batteries. In fact, at “room temperature” (about 70 degrees F) NiMH and NiCD batteries will self discharge a few percent PER DAY. Storing them at lower temperatures will slow their self discharge rate dramatically. NiMH batteries stored at freezing will retain over 90% of their charge for full month. So it might make sense to store them in a freezer. If you do, it’s best to bring them back to room temperature before using them. Even if you don’t freeze your NiMH batteries after charging them, you should store them in a cool place to minimize their self discharge.