Recent HD Sportster model batteries are Absorbed Glass Mat (AGM) versions. The ones on the 883 models are rated at 12v, 12Ah & 200CCA. ¹⁾

Here's the sales pitch made for HD batteries:

H-D AGM²⁾ Original Equipment Batteries³⁾

Genuine H-D Batteries offer the latest technology for higher cold cranking amps, long life and improved rechargeability. Featuring the latest AGM technology and great Harley-Davidson graphics, these batteries are durable, long-lasting and trouble-free. Made in the U.S.A.

1) Completely sealed, valve regulated maintenance free design eliminates acid spills and corrosion damage.

2) Re-engineered vent system is specially designed to minimize leakage.

3) Exclusive molded terminal design increases strength and durability.

4) Unique positive post bushing resists vibration damage and retards acid leaks and corrosion.

5) Heat sealed cover prevents electrolyte leakage and improves reliability.

6) Larger diameter through-partition welds direct more power to the starting motor.

7) Heavy top lead improves plate-to-lug adhesion for vibration resistance and long life.

8) Plates are lock-bonded together, reducing vibration damage for longer life.

9) Exclusive calcium/calcium alloy grids provide highest cranking amps and lowest self-discharge. Full frame, power path design directs more power to the terminals for quick, sure starts.

10) High density oxide provides maximum power-perpound or dependable “high cycling” service.

11) Tear-resistant AGM* separators protect plates, ensuring long life.

12) Exclusive demineralized electrolyte improves service life. Metered addition of electrolyte means no excess acid.

13) Positive terminal protector (not shown) protects against short circuits and sparks.

14) Stainless steel terminal bolts (not shown) won’t rust or corrode.

15) Distinguished Harley-Davidson Bar & Shield is molded into case, for quick, confident recognition.

Motorcycle batteries built and rigorously tested to Harley-Davidson’s exacting requirements. H-D® AGM battery ratings are determined by the strict regulations and testing of the Battery Council International.

An aftermarket battery, the Extreme Magna Power EXT16 is also an AGM battery, rated at 12v, 19Ah & 325CCA (17-lbs). It is a full size battery - 6.875 Length, 4.0 Width, 6.125 Height - Tight fit

Additional research found this claim at http://www.impactbattery.com/batteries/powersports/brands/magna-power

ETX Magna Power Sealed AGM Batteries

The familiar looking ETX numbered Extreme Magna Power battery is manufactured by East Penn Manufacturing in Lyons, PA. You read that correct, these are American Made motorcycle batteries.

It is not too often you hear made in USA anymore, especially when it comes to power sport batteries! The powerful Magna Power battery line is actually marketed under EPM Products out of Baltimore, MD as a subsidiary of East Penn Manufacturing.

It is also worth noting that these Magna Power motorcycle batteries are private labeled for many automotive box stores including O'Reilly's (Super Start Extreme), Auto Zone (Duralast Gold) as well as Pep Boys (Magna Power) and Advanced Auto (AutoCraft).

There are several other well known and online brands that use the East Penn Extreme Magna Power battery. They include Braille, Big Crank, ThrottleX, Duracell, Deka Intimidator (which is the house brand sold directly by East Penn Manufacturing vs. the Magna Power and private label division marketed by EPM Products), Harley Davidson and Power Source (Lightning Start) to name a few.

Not all of them will use the ETX battery numbering system and will rely on an internal stock code system or unique SKU identifier, but rest assured they all come from the same factory and will provide the power you need to rule the road.

A summary list from the above claim suggests these batteries are all USA Made:

Super Start Extreme (O'Reilly's)
Duralast Gold (Auto Zone)
Magna Power (Pep Boys)
Autocraft (Advance Auto)
Braille
Big Crank
ThrottleX
Duracell
Deka Intimidator
Harley Davidson (65991-82B OEM battery?)
Lightning Start (Power Source)

As with any product, you might rightly expect that some versions of the products from these manufacturers vary in quality due to materials and processes being different. But in general, based on the above link, all these branded batteries should have similar (if not the exact same) qualities.