Here's a quick and cheap ($209.99) way to drop 22 lbs off of your ACR and also have a more stable battery overall.
Lithium batteries provide the same output voltage regardless of how much the battery is charged/discharged.
The factory ACR battery weighs 24.34 lbs. (the ACR battery is already 7 lbs lighter than non-ACR's)


I used this battery-
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
It's about 1/3rd the price of the Braille lithium batteries I've used in the past.

If you are going to hook this up to a tender, you'll need this as well-
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

I used these terminal adapters for the negative side- (I cut the black plastic part off)
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

For the positive side you can just unscrew the large round connector off the positive cable and screw the cable right to the battery.

I glued a thin pad to the bottom of the battery just for added protection of the battery.

I used this strap to secure the battery- https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
I put the factory screws through the strap with a large washer. I have this setup on my '13 too so I can swap batteries if needed.

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