Editing Auto battery

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=Overview=
The automobile battery industry uses more of the world's lead than any other industry. Without the auto battery, there would be no electric starter- which was a big part (along with the electric starter) in the early automobile gaining widespread acceptance. 

Early auto batteries were almost all 6 volt. This required large cables/wires and was superseded by the still-used 12 volt battery in its various forms.

==Types of auto batteries==
The major battery types are flooded lead/acid (wet cell), gelled, and AGM (Absorbed Glass Mat).

===Lead acid===
Most used by far is the "flooded lead acid" battery. Also known as a "wet cell" battery. It is relatively cheap to manufacturer and offers an adequate service life. However, they are heavy and relatively inefficient.

<table border="1" cellpadding="2" cellspacing="0" ><tr bgcolor="#CCCCFF"> <td width="251">
'''Battery Voltage''' <br> 12V battery after car<br> is off for one hour</td>
    <td>'''Relative charge'''</td>  </tr>
  <tr>    <td>12.6&nbsp;V</td>
    <td>100%</td>  </tr>
  <tr bgcolor="#eeeeee">    <td>12.4&nbsp;V</td>
    <td>75%</td>  </tr>
  <tr>    <td>12.2&nbsp;V</td>
    <td>50%</td>  </tr>
  <tr bgcolor="#eeeeee">    <td>12.1&nbsp;V</td>
    <td>25%</td>  </tr>
  <tr>    <td height="22" width="251">
Less than 12&nbsp;V</td>    
  <td height="22">Dead</td></tr></table><br>

===Gel cell===
Gelled batteries, or "gel cells" contain acid that has been "gelled" by the addition of silica gel, turning the acid into a solid mass that looks like hard Jell-O. The advantage of these batteries is that it is impossible to spill acid even if they are broken. The disadvantage is that they must be charged at a slower rate to prevent excess gas from damaging the cells. They cannot be fast charged on a conventional automotive charger or they may be permanently damaged.

===Absorbed Glass Mat (AGM) batteries===
First designed for and used in aircraft in around 1985, the AGM battery had design parameters of being safe from spills, high power-to-weight, a long service life, and good reliability.

====Performance==== 
The AGM battery is currently among the best batteries you can buy for your prized ride, according to some. A small 15 lb. AGM battery can have 680 cranking amps, so unless you are running very high compression it should start most any vehicle it's designed for with ease. Even a new flooded lead acid battery will lose much of its life if it's allowed to go dead more than a few times. Good news for those who store their vehicle for long periods is that AGM batteries have the lowest self-discharge rate of any cranking battery, less than 1/10 (10%) of a flooded lead acid battery. This means no need for a trickle charger or even a boost charge in the springtime in many cases. Instead, just turn the key and start the vehicle (after the fuel is replenished, etc.), because after 8 months of sitting it will have retained >90% of its original charge. 

While a 15 lb. AGM battery may have the cranking amps of a 50 lb. flooded lead acid battery, unlike the heavier battery's 65 amp-hour capacity, the AGM battery may have only a 16 amp/hr. capacity. What this means is that your engine had better start quickly or the battery will become discharged. If this is a problem, you will have to move up to a larger capacity AGM battery. And if there are high amp draw accessories like a big stereo, running lights, electric cooling fans, etc., the battery capacity needs to be able to accommodate them all and the charging system needs to be up to the task as well. 

One of the best features is no corrosion on the terminals or the surrounding environment where you installed the battery. You can use AGM batteries in many applications because they can be installed in an orientation without spilling or leaking. There are dual-purpose batteries that are often used in RV's, etc. that serve as deep cycle '''and''' starting batteries. These are handy when space is a concern. Because of their design they can be shaped in many ways but they are also available in the industry-standard case sizes as well.

====Construction====
The acid of an AGM battery is held within the matting that occupies the space between the lead plates. There is no need for the acid being "gelled", so the acid is more readily available to the plates than a gel acid battery. The AGM battery also has a very low internal resistance, meaning it can deliver and receive higher amperage. In most cases, AGM batteries can be charged at normal regulated flooded lead acid battery charger voltages. Therefore, in most cases it is not necessary to recalibrate charging systems or purchase special chargers. 

[[File:800px-AGM inside.jpg|thumb|left|300px|From left to right: positive plate, glass mat separator, negative plate. On the far right is the complete cell.]][[ File:Agm cutaway.jpg]]
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====Various applications====
The picture below is a hot rod scooter powered by four 12 VDC AGM batteries (48 VDC total) connected in series to a 700 amp controller. This death trap of a scooter can reportedly outpace a Corvette to 40 mph. More at [http://tbuckets.lefora.com/2011/01/28/agm-batteries-the-good-the-bad-and-the-ugly/ AGM batteries- The good the bad and the ugly].

[[file:AGM_scooter.jpg|left|border|300px]]
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==Resources==
*[http://www.batterystuff.com/kb/articles/battery-articles/battery-basics.html Battery basics]: A Layman's Guide to Batteries, from batterystuff.com

[[Category:Electrical]]
[[Category:Undeveloped articles]]
[[Category:Undeveloped Electrical articles]]