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STM Small Battery Kit for 2015-2021 WRX/STi

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Regular price $294.00
Sale price $294.00 Regular price
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The STM 680 small battery kit for 2015-2021 WRX/STi allows you to install a smaller, lighter battery to save 18 pounds while lowering the center of gravity. This kit fits cleanly in the stock location and installs in minutes with the new tie-down hardware. Includes a non-slip pad to keep the battery snug and reduce shock while driving.

The battery tie-down kit is available with or without the Odyssey PC680. Battery purchase will include a set of new terminals. Please note we cannot ship batteries outside the continental USA.

Vehicle Fitment:
2015-2021 Subaru WRX
2015-2021 Subaru STi

Stock Battery Weight: 34.10 pounds
STM-BATK-15WRX-PC680 STM Battery Kit with Odyssey PC680 and Terminals 15.20 pounds
18.90 lighter than stock
STM-BATK-15WRX-TD-680 STM Battery Tie Down Kit (Battery is not included)
Features:
• 19 pounds Lighter than Stock
• Utilizes Existing Points for Mounting
• Lower Center of Gravity
• Non-Slip Pad to Keep Battery Snug and Reduce Shock
• Stainless Hardware

Install Notes:
• Small batteries can fail if the posts are not torqued to 50 inch pounds. Additional torque will cause damage to your battery, so please be careful when installing.
• Lay the battery flat with the terminals on the highest side.

Recommended Battery Charger:
CTEK MXS Battery Charger (40-206)

Performance Notes and Warranty:
These small battery kits are used for racing! They are not designed for for an average daily driver and would absolutely NOT support any sort of aftermarket stereo and they are not great in cold temperatures. These batteries are not even intended for automotive use, but we and most of the racing community use them as such. STM does not warranty batteries. We offer the STM Lifetime Guarantee on the STM Battery Tie-Down, but we cannot warranty the batteries themselves as we are all using them in a way they were not intended for and any attempt we have made to have them warrantied by the manufacturer has been denied.

The typical life we get from one of these batteries varies from 1 year to 10 years. Expect to treat this battery as a maintenance item - once it's done, just get a new one. For a typical 300-600 HP street car, it's fine to sit for a week, drive and race on the weekends or drive everyday in nice temperatures (40-90°). If it sits longer than 2 weeks or if it's in freezing temps, we recommend keeping the charger handy.

These batteries will start your car with no problems and charge naturally with a working alternator, but if you're having ignition issues... in our experience you'll get about 10-15 attempts off a small battery before it starts to fade if it's fully charged. If it's been sitting untouched in a cold garage for 2 months, don't even bother trying, put it on a charger first.

STM Battery Tie-Down Kit Includes:
(1) STM Engraved Aluminum Bracket
(1) Battery Pad
(2) 1/4-20 Stainless Wing Nuts
(2) M6 Stainless Flat Washers
(1) M6x16 Bolt
(1) M6 FenderWasher
(1) M6 Nut
(1) J-Tie
(1) L Tie
(1) Terminal MU800890

Additional Notes:
The batteries no longer include the STM battery top decals.
We no longer carry the black Genesis battery.

Previous Part Numbers: STM-15WRX-BATK-BK-PC680, STM-15WRX-BATK-BK-GEN16, STM-15WRX-BATK-AL-PC680, STM-15WRX-BATK-AL-GEN16, STM-15WRX-BATK-AL, STM-15WRX-BATK-BK, STM-BATK-15WRX-GEN16
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STM Small Battery Kit for 2015-2021 WRX/STi

$294.00

Why Drivers Choose FAST of West Chester

  • I can't recommend this place enough. Being able to trust a shop in the performance world is big. The 2hr drive to get there, is worth knowing the job will be done right. Very happy to have found this shop, to
    support my builds going forward.


    Donald Wojnar
  • I recently had the pleasure of working with FAST of West Chester for some performance upgrades on my 2022 WRX, and the experience was nothing short of exceptional. I opted for a Borla S-Type exhaust and Cygnus Coilovers, and the team at FAST nailed the installation, fitment, and setup to a T.


    Adam Cranston
  • The team at FAST are excellence in every way. First, I consulted with Dave on mods for my HPDE track car. He listened and advised me on the best parts & mods to achieve my goals. He was patient & gave me space to research the options presented & worked with me through several changes before we built. Second, the build execution was flawless, proper heat shielding, bracing and poly everywhere. All components worked as advertised.


    Bryce Budd
  • This place has been my go to shop for all things Subaru. From simple service to performance parts and tuning, they have been top notch.


    William Brunell
  • Excellent shop. They installed a Cobb Stage 2 DP and Whiteline Sway bars and end links on my 2013 WRX. The work was done right and clean. The estimate was accurate. They were very knowledgeable, friendly and gave me the straight scoop on exactly what I was getting for the money
    and what I needed to get where I want to be with it. I'd recommend them
    to any car enthusiast.


    Devin Greco
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Does it come with a warranty?

Most products we carry include a manufacturer warranty. Since we work with top performance brands, warranty coverage can vary by product. If you have questions about a specific item, reach out — we’re happy to help.

Do you offer installation help or advice?

Yes — we don’t just sell parts, we install and tune them too. FAST of West Chester is a real performance shop, and we’ve worked hands-on with many of the products we carry. If you have questions about fitment, installs, or building your setup, our team can point you in the right direction.

How fast is shipping?

Many of our products ship the same day or next business day, depending on availability. We work hard to get parts out fast so you can get your build moving without delays.

What’s your return policy?

Returns for exchange or refund are accepted within 30 days of receiving your order. Items must be in new, unused condition and in original packaging. If you have any questions, our team will help make the process easy.

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