This page explains how batteries work, their chemical composition, how they're used, how to care for them and so much more.

Batteries are those amazing little things that allow us to enjoy our life on the move. But there is a lot to understand about batteries and it can be confusing trying to find the right one. We hope to explain everything you'd want to know about batteries!

Batteries: Your Questions Answered

o What makes a battery “high-capacity”?

>> In the simplest terms, a high-capacity battery generally means the battery has more battery cells packed into the battery casing and will thus store more power. The result is that you receive much longer use time between each charge.

o My battery has multiple contacts. What are they for?

>> Batteries all have at least two contact terminals -- a positive (+) and negative (-) contact. However, most modern batteries -- like digital camera batteries and MP3 player batteries -- also have additional contacts usually referred to as a “data contact”. These are used to communicate with your device in some way. The only two contacts you need to worry about when recharging the battery with a battery charger is the positive and negative contacts.

o What does mAh stand for on a battery?

>> mAh stands for milliamp-hours and is the measure of the power capacity of a battery; the higher the mAh rating the larger the power capacity of the battery. Unlike voltage (V) the mAh rating can be much higher or much lower than your original battery and it will still function with its intended device. NOTE: the larger the mAh rating the longer the battery will last without having to be recharged.

o How long does it take to charge a battery?

>> Batteries will all charge at different rates depending on the battery type (i.e. Li-ion vs. NiMH) and mAh rating. Lower capacity batteries charge quicker than higher capacity batteries. It's hard to determine exactly how long a battery will take to charge. However, generally smaller 3.7V batteries (like cell phones batteries or video game console batteries ) generally charge in 2 - 4 hours. Larger 7.4V batteries (like camcorder batteries , GPS batteries , or two-way radio batteries) generally charge in 4 - 8 hours. NOTE: these are general time frames and may differ with your particular battery and device.

o How does a battery work?

>> In the most basic terms a battery cell is made up of three components: an anode (-), a cathode (+), and the electrolyte. Due to a chemical reaction within the battery the anode builds up an excess of electrons. This causes an electrical difference between the anode and the cathode. The electrons want to rearrange themselves and displace the extra electrons in the cathode; however, the electrolyte ensures the electrons cannot travel directly to the cathode. When you close a circuit (i.e. connect a wire or a “conductive path” between the anode and cathode) the electrons are able to travel to the cathode. Placing an electronic device within that circuit (i.e. light bulb, blender, mp3 player, etc.) provides power to the device along the way.

Over time this electrochemical process alters the chemical make up in the anode and cathode and eventually they stop providing electrons. This is what happens when a battery “dies”.

You can recharge a battery by reversing the direction of the flow of electrons and restore the anode and cathode to their original electrochemical state and renew the capacity of the battery.

o How should I care for my battery?

>> If you want your rechargeable battery to last for many years there are a few simple steps you can take to ensure long life.

1) Don't Over Charge The Battery - The easiest way to kill a battery's ability to retain a long charge is to leave it on an AC/DC battery charger or attached to the AC power adapter for too long. Leaving the battery on the charger for days, weeks, or months will over stress the already full battery cells and will ruin the battery.

2) Avoid Heat - Leaving your battery in a hot car or in direct sunlight is a sure way to ruin a battery. Do your best to keep your battery at room temperature whenever possible.

3) Don't Store A Dead Battery - Whenever you're finished using a battery give it a full charge and store it in a dry room temperature location. Try to ensure you use the battery at least once every couple months and always give it a full charge when you're finished. Dead batteries will eventually lose their capacity to hold a charge, and even charged batteries will naturally discharge overtime. Storing a battery for many months at a time will naturally cause the battery to go dead and eventually you'll be storing a dead battery; ruining its capacity to hold a charge in the future.

o What is the shelf life of a battery?

>> It's not recommended to keep a brand new battery “shelved” longer than 4 - 6 months without receiving a charge. Used batteries should not sit unused for more than 2 - 3 months without receiving a charge.

o How many years will my rechargeable battery continue to take a charge?

>> If cared for, most consumer rechargeable batteries can continue performing well for 3 - 4 years. If a battery is over stressed (left on the charger) or kept in hot temperatures a battery may only last 1-year or less. It's important to store your battery fully charged, discharge and recharge your battery at least once every 2 - 3 months, and keep your battery in a dry room temperature location to receive optimal long-term use.

o What is voltage? Can it vary?

>> In layman's terms, voltage (measured in volts or V) denotes the power output of a particular power source. When shopping for batteries you'll sometimes see a slight difference in voltage ratings on batteries. One battery may output 7.2V and another compatible battery outputs 7.4V. This is very common and is based on different manufacture designs. The difference between 7.2V and 7.4V is insignificant and your consumer electronic will manage the incoming voltage.

o My AC Adapter has different voltage output than the battery. What gives?

>> The voltage (V) and amperage (A) output of an AC adapter is sometimes higher than that of the device's battery. The reason is often the AC adapter is providing power to both recharge the battery, as well as power the device. So don't always look to the battery to try and determine the correct voltage output for the AC adapter or vice versa.

o What is the difference between Li-ion, NiMH, NiCd, etc.

>> When shopping for batteries you'll notice numerous battery types. Some of the most common battery types in modern consumer electronics are Li-ion (lithium-ion), Li-poly (lithium polymer), NiMH (nickel-metal hydride), and NiCd (nickel-cadmium). The difference between the batteries is numerous and each has differing chemical components, design, and physical structure. Manufactures develop their devices with these battery types in mind, so it's important to replace your device's battery with the same battery type.

o Will my PDA/Smartphone lose data if the battery is removed?

>> On older PDA models you will lose the data stored on your PDA when the battery is disconnected. On those older legacy models you need to ensure you sync your PDA's information to your computer before disconnecting the battery. However, this is an outdated method of storing data and is no longer an issue on modern cell phones, smart phones, or tablets. You can remove the battery without losing any data stored on your device.

o Is my battery compatible?

>> When shopping for a replacement battery for your device ( laptop battery , vacuum battery, survey equipment battery, etc.) you should first look for two things: 1) the battery model number, 2) the device model number. You can usually find the battery you're looking for with the battery model number. Centenex.com also advertises compatible device models for any given battery. Many manufactures will use the same battery across many (many) different products and models. Also, some manufactures will make their devices compatible with other manufacture battery models; so one battery may work for hundreds of different products. At Centenex we do our best to provide as much up to date information as possible on compatible batteries. If you can't find what you're looking for please contact us directly and we'd be happy to help.

o What does the IC Chip do in a battery?

>> Many modern batteries contain an IC chip which is used by the device to communicate in some way with the battery. Some devices require very specific chips and information in order to use a compatible battery. Often this is a way for brands to try and ensure consumers buy their manufactured battery, rather than purchase from a third party. Centenex only sells batteries with compatible IC chips that function just like the OEM battery.

o What is a dry cell battery?

>> A dry cell immobilizes the electrolyte as a paste with only sufficient dampness in it to permit current to flow. Unlike a wet cell, a dry cell can function in any orientation devoid of spilling as it contains no open liquid, making it appropriate for portable devices.

o How do I remove my battery?

>> Every different electronic device has its own way of accessing the battery for replacement. Although we offer a precise tool kit that helps to open and access batteries in PDA, iPods, iPhones, MP3 players, etc. your battery may require very specific instructions on replacing the battery. For liability reasons Centenex.com does not offer instructions on replacing batteries, however, the web and YouTube are full of help tips and video on replacing your battery. Often searching for “how to replace” [your battery model] will find the exact information you're looking for.