Shopping for new rechargeable batteries online is a smart move. You can get a better battery and save a bundle of cash too, when buying batteries online if you know just a little about rechargeable batteries.

Here's a quick mini course on batteries that will enable you to select the right battery and be sure you are getting the best value for your money because you'll know what you're talking about. (Now pay attention class, there may be a pop quiz on this!)

Battery Fuel Sale Items:

Basic Battery Terms

"Cell" An electrochemical system that produces free electrons.  Think of it as tiny pump that pumps electrons around a circuit.

"Battery" Two or more (often many) cells arranged in a manner to either deliver more pressure (volts) or more flow (current-amps) for the circuit. Sometimes we mistakenly refer to a cell as a battery when we say something like "I need new batteries for my flashlight", no one, not even me, will say "I need new cells for my flashlight". Yes most flashlights run on a battery, but that battery is made up of two cells. Just food for thought.

"Battery Type" (This is information for extra points only.)  Two battery types are "primary" and "secondary".  Primary batteries are not rechargeable and are often the less expensive "flashlight" batteries ("cells") you see at the supermarket check out.  Secondary batteries are rechargeable and are more expensive, but can be recharged over and over again saving you money in the long term.

Now here's the meaty stuff, it isn't rocket science, just looks like it!

"Ni-Cd" Nickel Cadmium batteries.  One of the oldest rechargeable battery technologies  still in use today. These batteries are used in older products that require a high amount of power. They all seem very prone to 'Memory Effect'(we'll get to that).  You may hear people say "oh, that uses nye cad batteries" which means Nickel Cadmium.

"Ni-MH" Nickel Metal Hydride batteries. This neat battery type has just about replaced the old Ni-Cd batteries. These batteries have higher capacities, around 30% more than a Ni-Cd cell of the same physical size. Nickel Metal Hydride batteries seem to suffer much less from 'Memory Effect'. A better choice when replacing old Ni-Cd's.

"Li-ion" Lithium Ion Batteries. This is the newest and best of all the battery types now available. Lithium Ion Batteries offer the same power as a Ni-MH (Nickel Metal Hydride) battery, but it's in a smaller, lighter package. Plus, these batteries do not suffer from 'Memory Effect' but right now they are a little more expensive to manufacture.  This battery gives you the most value for money spent.

OK you got through that, but you're probably wondering about memory effect.

"Memory Effect" A phenomenon in which a cell or battery that is used in successive cycles to the same, but less than full, depth of discharge temporarily loses the rest of its capacity at normal voltage levels.

What that says in English is, if you recharge a battery that is subject to memory effect, before it's all the way discharged, it will 'think' that it doesn't have as much capacity to hold a charge as it really does.

So if you have those older Ni-Cd batteries that seem to be going bad, you might be able to bring some new life to them by simply running them all the way down and then recharging.  Do this for a few times and see if they improve.  If not it's time to go shopping.

If you treat your rechargeable batteries right, you won't need to worry about diminished recharge capacity (memory effect) for at least 400-500 recharges.

Battery Chargers

Important:  If you decide to replace those old Ni-Cd batteries with the better Ni-MH Nickel Metal Hydride batteries and get a 30% boost in use between charges, you will need a new charger.  Your old Ni-Cd charger will overcharge and damage Nickel Metal Hydride batteries.  Interestingly, you can use a typical Nickel Metal Hydride charger to charge Ni-Cd but not the other way around.

For the environment, a solar battery charger is the absolute greenest choice.  You get free energy from the sun for all your devices and you have eliminated some of the pollution associated with generating electrical power. Depending on where you live and how much sun gets on the panel, they might take longer to charge than your plug in charger so you might want to have a few extra batteries on hand.

Laptop Computers and Lithium ion Batteries

There are few things in life as frustrating as when your laptop battery suddenly won't charge anymore or it only lasts for an hour or two. This means it's time for a new battery. You'll want to choose the battery with the longest life available for your computer and the new Li-ion Lithium Ion laptop batteries are the right choice here.
 
Here's a tip that most people don't realize about these batteries, their life span depends upon their actual age and not the time from which they were first charged, or even the number of times they have been charged. Lithium Ion laptop batteries begin to lose capacity gradually from the date of manufacture regardless of the amount of charging cycles they have been through. Therefore the manufacturing date is useful to know, especially if there is a large time gap between manufacture and end use, but they are still the very best choice for laptops.

You'll want to protect your investment in your new Li-ion replacement laptop battery.  The worst enemy of your new battery is heat. These batteries should be kept cool. They age faster at higher temperatures, so keep them as cool as possible when not in use. They can even be safely stored in your refrigerator which is the best for prevention of aging, but never put them in the freezer.

The Li-ion battery should never be discharged below a certain point, because then the battery will be damaged irreversibly. Almost all the devices that use them have a built in monitor system to shut everything down when the charge level meets that minimum threshold. This is the reason why this type of battery is designed and built specifically for certain devices. This means you must pick the right one made for your type of computer.

Li-ion batteries are ideal for all electronic devices requiring a reliable, high-energy power source. Things like cellular phones, PDAs, laptops, and MP3 players all benefit with these great new batteries. Li-ion batteries produce the same amount of energy as Ni-MH but they weigh approximately 20 to 35 percent less. Li-ion batteries are very environmentally friendly since they don't contain bad toxins such as cadmium or mercury to pollute our worlds landfills.

They are powerful and lightweight, they do not exhibit any memory problem and can be recharged anytime without first having to be completely discharged like the old Ni-Cd.