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Receive Up To 30% Off Your Online Purchase Of Select Parts And Accessories
Use promotional code MMJ30 at checkout to receive 30% off the following categories: Select Brake Parts, Select Hi-Performance and Truck Accessories, Batteries, Paint, Splash Guards, Select Ventvisors & Bug Shields, Springs & Spacers, Water Pumps, Belts, A/C Parts, Starters, Alternators, Fuel Pumps, Radiators, Radiator Fans, Thermostats, Caps & Clamps, Clutches, Spark Plugs, Plug Wires, CV Axles, Battery Chargers & Booster Cables, OE Locks, Rack & Pinons, Window Motors, RainX Wipers, Appearance Chemicals, Floor Mats, Lift Equipment, Hand Tools, Travel Accessories, Car Covers, Seat Covers, Wheel Covers, Body Repair, Collectibles and Apparel.

Use promotional code MMJ20 at checkout to receive 20% off the following categories: Ignition, Shocks & Struts, Chassis, Jumpstarts, Air Filters, Oil Filters, Bearings & Seals, Engine Parts, Wash Accessories, Outdoor Lifestyle, Towing, Mini Air Compressors, Tire Repair Accessories, Mufflers, Grease/Oil, Additive Chemicals, P/S Pumps, Cooling Product, Timing Belts, Specialty Tools, Radiator Hose, Motor Mounts, Mirrors, Lug Nuts, Sealants/Adhesives, Fuel Filters, P/S Hoses, Gas Cans, Oil Change Accessories, Help, Wiper Motors, Loaner Tools, Air Compressors, Horns, Books, Distributors, Sun Control and Exhaust Adapters.

Use promotional code MMJ15 at checkout to receive 15% off the following categories: Test Equipment, Power Tools, Emergency Supplies, Electronics and Stereo & Accessories (MAP pricing Exclusions).

Offers not valid in combination with any other discounts, promotions or items already on sale. Not valid on gift cards, special orders, installed merchandise, commercial or fleet purchases. Those products that are included in these offers will be displayed in product search results and product detail pages. Excludes the following brands: WeatherTech, Champion, Powerstop, Razor, Traxxas, Superchips, Hypertech, Edge, Bully Dog, Diablo, Edelbrock, Holley, NOS, Proform, Specialty Auto, Autometer, Accel, K&N, Kenwood, Pioneer, Sony, Thule, Thule Karrite, JVC, Flowmaster, Hurst, B&M, MSD, Moog, Wagner, Philips and BBK Performance. Valid online until 11:59 PM EST on 11/22/17.

Receive 10% Off Wagner branded brake parts with your online purchase. Use promotional code: WAGNER10.

Receive 20% Off Select Champion branded products with your online purchase. Use promotional code: CHAMP20.

Receive 10% Off Select FelPro branded products with your online purchase. Use promotional code: FELPRO10.

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AGM (Absorbed Glass Mat) batteries are renowned for their ability to outlast regular lead acid batteries. AGMs are completely spill and leak proof thanks to their construction. These car batteries are new to the automotive world – a design that replaces conventional acid flooding of the battery cells with absorbent separators and cells held under compression.



What is an AGM Battery

AGM is an advanced battery technology that allows the electrolyte (acid) to be uniformly distributed across the battery plate active material. This allows the battery to tolerate repeated deep discharges and provides an overall longer service life. AGM batteries are safer because there is no free acid to spill and they are highly resistant to failure from vibration. They also allow installation in virtually any location (even at odd angles) and are famous for lasting up to two times longer than regular lead acid batteries.

How do AGM Batteries Work?

These batteries are constructed with glass mat separators designed to wick the battery electrolyte between the series of battery plates. The electrolyte is held in the glass mats, as opposed to freely flooding the plates like in a lead-acid battery. Very thin glass fibers are woven into a mat to increase surface area enough to hold sufficient electrolyte on the cells for their lifetime. The electrolyte is distributed evenly across the active plate material. and contains only enough liquid to keep the absorbed mat wet with the electrolyte. The maximization of electrolyte-to-plate coverage enables these batteries to far exceed the performance of conventional flooded lead acid batteries. AGM batteries are known as safe non-spilling car batteries.

How are AGM Batteries Made?

Plates and separators are compressed prior to insertion into the case, allowing them to be held tightly - a technique that lends to vibration resistance. The glass mat plates allow for the even distribution of electrolyte over the entire surface area of its adjacent lead plate, due to its ability to hold acid. The plates in an AGM battery may be any shape: flat, bent, or rolled. AGM batteries, both deep cycle and starting, can be built in a conventional rectangular case or other design.

Why do AGM Batteries Fail?

  • As with all batteries, the active material eventually wears out
  • Gradual capacity decline over time means more predictable replacement intervals
  • Overcharging. AGM is more sensitive to being overcharged, which will shorten life
  • Keeping battery in an extended discharged state
  • Must be stored in charged condition

What are the Symptoms of AGM Battery Failure?

  • A change in the sound of the starter (decrease in cranking speed) is the best indicator of impending failure
  • A 12-volt battery should be between 13.2 -13.8 volts at rest. When the battery can’t hold a charge, it is getting close to dying

What are Implications of AGM Battery Failure?

  • Complete failure most frequently results in a no-start condition
  • The alternator is designed to replenish the battery. A battery that is failing can damage an alternator if not replaced when required

If you have questions or concerns about AGM batteries or any of your vehicle’s components, come into your local pep boys where we can answer any question, help you find any part, or perform any vehicle service you might need.

If you want to learn more about other car parts, especially as they apply to your vehicle’s electrical system, we recommend reading up on alternators, starters and lead acid batteries.