Your Guide to Battery Types

Every mobile electronic device we own runs on battery power, yet we take batteries for granted - at least until they run out of juice. No matter what kind of device battery - laptop battery, cell phone battery, camcorder battery, remote control battery - you need, it's helpful to know the various kinds of battery types and their uses.

Gel Battery - A gel battery is also known as a sealed lead acid (SLA) battery, and its distinguishing feature is that it doesn't have to be kept upright in order to work. An SLA battery continues to perform in extreme conditions, such as hot temperatures, or under vibration. SLA batteries are often used in wheelchairs, scooters, and uninterruptible power sources. It's best to keep an SLA battery charged, or to charge it more often than you would other types of batteries.

NiMH - NiMH stands for Nickel Metal Hydride and is the battery of choice for many cell phones, camcorders, digital cameras, GPS systems, PDAs, and other personal electronics. NiMH batteries are also used in hybrid cars. An NiMH is a rechargeable battery that is similar to a nickel cadmium (NiCd) battery, but that has double or triple the capacity of a NiCd battery. It's best not to overcharge NiMH batteries.

NiCd - NiCd stands for Nickel Cadmium, and is a type of rechargeable battery commonly used in toys, electronic devices, and power tools. Although some people prefer NiMH batteries to NiCd batteries, a NiCd battery provides virtually the same level of voltage throughout its lifetime, and costs less than an NiMH battery.

LiION - LiION stands for Lithium Ion, and is one of the newest rechargeable batteries. Although they are more expensive than other types of rechargeable batteries, LiION batteries have more capacity and are often used in wireless phones, camcorders, and notebook computers. The downside of LiION batteries is that the length of their life commences from the date of manufacture, rather than from the number of times the battery is charged and discharged. It's best to regularly charge LiION batteries and store used batteries in the refrigerator. (Allow them to warm to room temperature before using them, though.)

Alkaline - Alkaline batteries are not rechargeable with a battery charger, but offer a large current over a long period of time. These batteries are often used in CD players and portable radios.

Carbon Zinc - Carbon Zinc batteries are known for their reliability over long periods of time in low-drain situations, such as for garage door openers or clocks. A Carbon Zinc battery is not rechargeable.

by: Chris Robertson

3 Car Stereo Components

Tips To Put Them Together

If you are new to the car stereo market, you may find yourself overwhelmed at the sheer number of parts and accessories that can make up a top of the line car stereo system. In this article, we'll explore the basic components that make up a functioning car stereo system.

1. The Head Unit: Making It Happen

You may have seen the term "head unit" before and not known what exactly it was. Simply put the head unit is the part of your car stereo that actually produces the music from radio, tape, CD, or other device. But nowadays you can also get head units for your car stereo that can play DVDs or music and video from USB flash drives or memory cards. Head units have sure come a long ways from when people used to install home stereo equipment in their vehicles!

2. Amplifiers: Bring the Boom

While your head unit may provide its own internal amplification (which may be enough for you), at some point most car stereo enthusiasts will want to add amplifiers to the mix. Simply put, and amplifier takes a signal coming out of your head unit, and makes it louder. Be careful when shopping for amplifiers, as some of the large amps can draw over 100 amps; this may be well over what your alternator and battery can provide, and can cause damage to those components.

3. Speakers: Woofers, Tweeters, What?

The best head unit and amp is completely useless without speakers. Speakers, regardless of size, all do one thing: take the electrical signal coming from either the head unit's internal amp or your external amp and turn it into sound, usually loud sound. The different types of speakers are classified by the range of sounds they can reproduce. Tweeters, for example, only reproduce high pitches, while woofers reproduce the upper bass ranges. Midranges make midrange sounds, strangely enough, while subwoofers cover sounds from the low bass all the way down to subsonics (those sounds you can feel but not hear). Subwoofers are usually the first candidate for external amplifiers, since they require large amounts of current to make that bone shaking bass.

Putting It All Together

Let's review: head units take your CD or tape and convert it to electrical signals. The amplifier makes this signal larger, and finally the speakers take that signal and make sound out of it. These are the base components you need for any car stereo installation. The accessories, such as crossovers and signal isolators, may or may not be needed for your particular application.

These are the basics you need to know for all car stereo systems. Now that you have a better idea what all these different terms actually mean, you should be able to shop intelligently for your new car stereo system. Just remember, as always, while you get what you pay for, you don't necessarily have to have the absolute best (and most expensive) parts for a good sound. More often than not, a midrange product will provide the best bang for your buck. And remember, it's all modular! You don't HAVE to buy every piece all at once. You can start with the head unit, and simply wire it's built in amplifier into your factory car stereo speakers. Add a sub and an amp later if you want, or replace the factory speakers with higher quality ones, it's all up to you.