Guide to Buying Good Quality Rechargeable Batteries

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Guide to Buying Good Quality Rechargeable Batteries

Rechargeable batteries are used in many applications, ranging from consumer electronics, to large megawatt systems connected to electrical distribution networks. Though rechargeable batteries, or secondary batteries, have an initial cost that is higher than disposable batteries, their total cost is usually lower. And this is a trend that should continue. The growth of electric and hybrid vehicles is pushing the development of rechargeable battery technology to reduce cost and weight, whilst increasing life.

Almost every consumer electronic device today uses some form of battery for power. Most devices designed to work with disposable batteries function just as well with rechargeable batteries of the same size and similar voltage. Some devices, such as laptops and cellphones, use batteries developed especially for that device. In such cases, buyers must ensure they buy the right model when purchasing a replacement battery.

When shopping for rechargeable batteries, it is important that buyers choose the right ones for the device. Even batteries of the same shape and size may vary in technology, capacity, and expected life. In the following sections, buyers can find information on the different types of batteries used in consumer electronics. This guide also introduces readers to rechargeable battery terminology, and explains how and where to buy quality rechargeable batteries at a reasonable price.

Rechargeable Battery Technology

There are several different chemical combinations used to make rechargeable batteries. Battery technology has evolved rapidly in recent years, and newer batteries offer better capacity, longer lives, and more recharge cycles than batteries designed only a few years ago.

The following sections discuss several common types of rechargeable batteries used in consumer electronics.

Nickel-Cadmium Battery

Also called a NiCd or NiCad battery, the nickel-cadmium battery uses nickel oxyhydroxide and metallic cadmium as electrodes. The original, wet-cell, nickel-cadmium battery was invented over a century ago, in 1899. Today, they are used in emergency lighting, standby power, and uninterruptible power supplies, amongst other applications.

Sealed nickel-cadmium batteries are available in the same sizes as standard disposable batteries. They were once popular for use in consumer electronics. However, the superior capacity and lower cost of nickel-metal hydride batteries has resulted in a drop in the usage of nickel-cadmium batteries. Furthermore, the environmental impact of disposing of cadmium has resulted in restricted availability of sealed NiCd batteries, especially in the European Union.

Nickel-Metal Hydride Battery

The nickel-metal hydride battery is similar to nickel cadmium in that it uses positive electrodes of nickel oxyhydroxide. However, the negative electrodes use a hydrogen-absorbing alloy instead of cadmium. They are commonly abbreviated as NiMH or Ni-MH. Nickel-metal hydride batteries have two to three times the capacity of an equivalent nickel-cadmium battery. They are also less environmentally harmful because they lack cadmium. The main disadvantage of NiMH batteries is their fast self-discharge. They can lose up to 20 per cent of their charge in the first month, and 4 per cent thereafter. Lower self-discharge models are available, but at lower capacities.

NiMH batteries are commonly available in AA and AAA sizes. The larger sizes (C and D) are not as readily available. NiMH batteries require charging before first use. Besides their use for consumer electronics, nickel-metal hydride batteries are also used extensively in electric and hybrid cars.

Lithium-Ion Batteries

Sometimes called li-ion battery, the lithium-ion battery is commonly used for portable electronics, including laptops, cameras, and cellphones. Lithium-ion batteries have one of the best energy densities (the amount of energy stored in a given region of space per unit mass), a slow self-discharge rate, and no memory effect (i.e. they do not lose maximum energy capacity over time). However, they have a cell voltage of 3.6V or 3.7V which makes them unsuitable to replace standard AA, AAA, C, or D sized batteries.

Lithium-Ion Polymer Batteries

Technologically descended from lithium-ion batteries, lithium-ion polymer batteries (also called Li-poly, Li-Pol, LiPo, LIP, PLI, or LiP batteries) have been in use since 1995. They are usually made of several identical cells joined in parallel to increase the discharge current capability. Lithium-ion polymer battery packs are a series of batteries joined together to achieve higher voltage. Li-poly batteries can be made in any shape, and are commonly used in personal electronics and radio controlled aircraft and cars. They have also been used in experimental electric vehicles.

Comparison of Various Rechargeable Batteries

The table below lists some of the differences in the common types of rechargeable batteries used in electronic devices.

Type of Battery

Voltage Per Cell


Discharge Rate

(Percentage per Month)

Recharge Cycles



Nickel-Cadmium (NiCd)





Nickel-metal hydride (NiMH)





Nickel-zinc (NiZn)





Lithium-Ion (Li-ion)





Lithium-Ion polymer





There are many other types of rechargeable batteries, some used for applications other than consumer electronics, others that use now obsolete technologies, and newer ones that feature emerging technologies.

Why the Lower Voltage Rating of Rechargeable Batteries Does not Affect Performance

A buyer in search of rechargeable batteries to replace disposable batteries discover that rechargeable batteries are usually rated at 1.2V instead of the 1.5V of alkaline disposable batteries. However, in actual use, the rechargeable battery usually outperforms an alkaline one. This is because rechargeable batteries maintain a constant, maximum voltage output for a longer time during their discharge cycle. An alkaline battery’s maximum voltage output, on the other hand, quickly drops.

Rechargeable Battery Terminology

When shopping for rechargeable batteries, buyers come across a variety of industry-specific terms. It is important to know what each term means in order to make an informed purchase, as well as to get the most out of the batteries during use.


The capacity of a battery is rated in milliampere-hours (mAh). This means that the battery can provide a current equal to the rated capacity for one hour. When comparing similar batteries from the same manufacturer, buyers should understand that a battery with a higher mAh rating can power a device longer than one with a lower rating. Unfortunately, since manufacturers follow different rating standards, this is not a reliable way to gauge battery performance when comparing batteries of different brands.

Charge Cycles

The term "charge cycles" refers to the number of times a rechargeable battery can be discharged and recharged during its lifetime. A battery with a higher charge cycle rating can be used longer than one with a lower rating.

Memory Effect

Memory effect is a phenomenon that affects nickel-cadmium batteries. It is also known as the battery effect, the lazy battery effect, or battery memory. When nickel-cadmium batteries are repeatedly recharged after only being partially discharged, the battery starts "remembering" the lower capacity. This can be avoided by allowing the battery to discharge completely.

Though nickel-metal hydride batteries do not technically have a memory effect, they do experience voltage depletion, even though it is to a much less noticeable degree. To eliminate voltage depletion, manufacturers recommend an occasional deep discharge (letting the batteries drain completely) followed by a complete recharge.

Availability of Rechargeable Batteries

Nickel-cadmium, nickel-metal hydride, and nickel zinc rechargeable batteries are available in the standard AA, AAA, C, D, and 9-volt battery sizes. In some cases, adapters are available for the larger C and D sizes. The adapter holds a smaller sized AA battery, and can be used in devices that require a larger size. Rechargeable batteries for electronic devices such as laptops, cameras, and cellphones are often device specific. Replacement batteries are made by the manufacturer or, in some cases, by third parties, specifically for that brand and model. When shopping for such batteries, buyers should make sure that the part or model number of the replacement battery matches the device.

Different Types of Chargers

Another important consideration when buying rechargeable batteries is which type of charger to buy. Buyers must purchase the right kind of charge, since rechargeable batteries can be damaged if overcharged. Several kinds of chargers are available, and every manufacturer describes them differently. A few common types include the following:

  •     Intelligent or "smart" chargers
  •     Simple chargers
  •     Trickle chargers
  •     Pulse chargers
  •     Inductive chargers
  •     USB chargers, and
  •     Solar chargers

Smart chargers monitor battery parameters such as temperature, voltage, and state of charge. They use this information to change the rate of charging, and are able to determine when to stop charging the battery. As a result, smart chargers cannot overcharge a battery. Note that it is inadvisable to use NiCd battery chargers to charge NiMH batteries.

Portable Power Packs

Portable power packs contain a pack of rechargeable batteries, used to charge other electronic devices, including mobile phones and personal music players, when no other power source is available. Once power is available, the depleted power pack can be recharged.

Buying Rechargeable Batteries on eBay

Buyers in search of rechargeable batteries can find a huge selection of batteries and chargers on eBay. Before beginning a search, be sure to verify the type of battery required for the the intended device. You can start a search directly from the eBay home page by entering phrases into the search bar. You can also search from any page on eBay. For most relevant results, buyers should enter specific keywords into the search bar. For example, after entering the phrase "AAA rechargeable batteries", the user receives a list of all AAA rechargeable batteries available on eBay. Buyers can also find a variety of bundles that include a charger with rechargeable batteries. Once the buyer selects a category, the list can be filtered based on various criteria including brand, chemical composition, type, and condition. Before making a purchase, it is a good idea to review the seller’s return policy in case the batteries are not as expected.


Rechargeable batteries are used in a variety of devices, ranging from consumer electronics to large uninterrupted power supplies. The technology used in rechargeable batteries has evolved and improved for over a century. Today’s rechargeable batteries offer a longer life and more charge cycles, and are environmentally friendlier than were previous generations. Though the initial purchase price of rechargeable batteries is higher than that of disposable batteries, the overall cost is lower because rechargeable batteries can be reused several hundred times.

Rechargeable batteries in common sizes can be used to replace their disposable equivalents. Rechargeable batteries are also available in device specific sizes for electronic devices including laptops, mobile phones, and cameras. When buying rechargeable batteries, it is important to purchase the right charger for the battery. Buyers in search of rechargeable batteries find that eBay offers a wide selection of batteries and chargers, at prices to fit any budget.

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