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Braille Battery Advanced AGM Lightweight Racing Battery 21 lbs

Braille Battery B3121


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Braille Battery Advanced AGM Lightweight Racing Battery 21 lbs $229.99
Advanced AGM Lightweight Racing Battery
  • 21 lbs
  • 6.6'' L x 5.2'' W x 6.8'' H
  • 892 Cranking Amps
  • 550 Cold Cranking Amps
  • 1380 (PCA) Pulse Cranking Amps
  • Right Side Positive

  • Braille Battery B3121 Details

    Advanced AGM Lightweight Racing Battery

    Braille Batteries are used by racers all over the world in the NASCAR, FIA WRC, FIA Formula Racing, Speed World Challenge Series, SCCA ProRally Series, SCCA Regional and National Racing, NASA Touring Cars, NIRA, NOPI and Battle of the Imports Drag Racing Series. Braille Batteries are also designed for deep-cycle use in premium vehicles with enhanced reliability and performance.

    Seeing a need for a Braille Battery that had extended reserve time and amp hour capacity, Braille changed the internal grid structure to suit customers looking for the highest amp hour to weight ratio for an AGM battery. The Spec 147-B3121 is perfect for daily street use, even in colder climates. Braille developed the 147-B3121 to excel at competition use and in situations where the battery is relied on to perform at a higher level than other batteries. This includes extreme audio systems and insane motors.

    The 147-B3121 features an industry leading energy to weight ratio. Enhanced Mat Technology (more surface area on the lead plates) combined with calcium full frame power path grids (increase cranking power), yields over 1300 Pulse Cranking Amps. With a weight of only 21 pounds/9.5kg, the B2015 is 10-30 pounds lighter than a standard battery of equal power. It also has a very high reserve time of over 1he 15 minutes to ensure the power to start even after using the vehicles accessories.

    Durability was also designed into this battery. Using high density oxide, Braille was able to offer a battery with true deep-cycling ability over the life of the battery. Heavy duty vibration resistant power posts resist cracking and deterioration common to many lightweight batteries used in harsh automotive environments. The 147-B3121 is a sealed unit that can be mounted in any position safely using its adjustable automotive terminal posts.

    Voltage: 12 volts
    Full Charge Voltage: 13.8 volts
    Short Circuit Current (Max Cranking Amps): 3000
    Pulse Cranking Amps (PCA) 5 sec @ 80F: 1380
    Pulse Cranking Amps (PCA) 10 sec @ 80F: 1207
    Pulse Cranking Amps (PCA) 20 sec @ 80F: 1066
    Cranking Amps 30 sec @ 80F: 892
    Cranking Amps 30 sec @ 32F: 742
    Cold Cranking Amps 30 sec @ 0F: 550
    Reserve Capacity: 1 hr & 15 minutes
    Capacity (C/20 rate): 31 amp hr
    Internal Resistance (ohms): 4 milliohms (.004ohms)
    Life Cycle @ 100% DOD: Up to 3100 cycles

    Carbon Fiber Heat-Resistant Casing, Horizontal and Vertical Mounting
    BCI Group: Usable for all Group Sizes
    Length: 6.6"
    Width: 5.1"
    Height: 6.8"
    Minimum Weight (lbs): 21 lbs
    Post Type: SAE Automotive Posts included & 6 x 1.0mm racing bolts included.
    Stainless Stud: Both Automotive SAE Posts and Race Style Bolts are Stainless with a 6 x 1.0mm bolt pitch

    Recommended Uses:
    Premium Luxury Vehicles
    Extreme Engine Builds - High Compression, Supercharger Systems, Large Cams, Underdrive Pulleys & No Alternators
    Extreme Audio Builds - Multiple Amps, Subs
    Extreme Cold Climates - Daily Driven or Stored Vehicles
    Custom Cars and Vintage Vehicles - No Acid to Spill protect and enhance your vehicle!

    Customers looking to save the most weight on a small displacement purpose built machine - check out the 147-B106 or 147-B14115 Batteries.


    Overall Length (in.)
    Height (in.)
    12 volts
    Reserve Capacity
    Width (in.)
    Battery Terminals
    Top and side
    Battery Type
    Battery Usage
    Cranking Amps at 0 Degrees F
    550 amps
    Cranking Amps at 32 Degrees F
    742 amps
    Sold individually
    Weight (lbs.)
    Manufacturer's Part Number:

    Smaller Battery, Same Power
    It's no secret that the lightest car retains the advantage in virtually any motorsports competition because it accelerates quicker, apexes faster, and stops shorter. That's why automotive enthusiasts continue to run Braille Advanced AGM Lightweight Racing Batteries. Barely tipping the scales, these batteries trim 25 pounds of weight or more off the front end of most vehicles, which results in a lower center of gravity and improved handling, especially when used in conjunction with other Braille lightweight parts.

    • Patented "sealed valve regulated" design completely eliminates acid spills and corrosion on terminals
    • Environmentally safe and does not need filling or maintenance
    • Dual removable terminals allow battery to be mounted in a variety of vertical or horizontal positions
    • Patent-pending high-quality brass SAE terminals designed to distribute the battery's electrical load
    • Stainless steel terminals allow higher bolt torque and help keep battery connected even in high-vibration environments
    • Every Braille Battery is performance certified and fully charged before shipping
    • Green-friendly manufacturing process with the highest concern for the environment and quality... recycled lead, plastic, and stainless steel ensure we'll have a future to race towards

      Note: AGM (Absorbed Glass Mat) batteries are fully charged, ready to install, and compatible with a vehicle's charging system. If additional charging is ever needed, an AGM-compatible charger will be required.

    JEGS Easy Kits are designed by JEGS Professionals to help you get all the performance parts you need.

    B3121 is rated 5.0 out of 5 by 6.
    Rated 5 out of 5 by from BIG POWER. Small package. Best size/weight/power ratio unless you spend over $1000 for a lithium battery. Jegs has great selection, pricing, and customer service.
    Date published: 2018-02-15
    Rated 5 out of 5 by from Awesome power in a little package It starts my 875HP bigblock chevy 14:1 comp When my total power battery same size would not.
    Date published: 2017-08-07
    Rated 5 out of 5 by from On time. Great service and great quality product. Many items to choose from.
    Date published: 2017-03-12
    Rated 5 out of 5 by from Great service, quality and cost. Great service and many quality parts to choose from. Thanks a lot.
    Date published: 2017-02-28
    Rated 5 out of 5 by from Braille Battery Great little battery, using this in my circle track car and has plenty of power to turn over my 11/1 engine.
    Date published: 2015-06-15
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    do I need a special charger with this battery

    Asked by: coopdog
    Any 12v AGM battery charger will work.
    Answered by: Dean R
    Date published: 2018-02-06

    What is the length of the warranty for this battery?

    Asked by: David AW
    Braille has a 1-year replacement on this battery.
    Answered by: Jon Jegs Tech
    Date published: 2017-11-08
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    Items You Need
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