Way back I looked into the "JDM" 51R battery tray and as usual things escalated. A 51R AGM battery gets expensive and ends up around 27 lbs which isn't that great, so I started looking into other options.
Settled on the Deka ETX30L, which is (probably) the same as a Braille battery and seems to be a solid and inexpensive AGM battery. About 20 lbs.
Needed to add some posts, which I got from Voltphreaks. Plenty of other options.
Then the OEM Subaru 51R rod and tie down work well. These are available from US Subaru dealers.
battery rod - 82161AG001
tie down - 82182AG010
Then the tray, which I made and had 3d printed in ABS so it wouldn't melt. This was about 35-40 bucks (I can't print ABS myself).
I added a strip of foam under the tie down.
And yeah, works great so far and looks OEM-ish. I work from home sometimes and don't turn the car on for a couple days at a time with no issues in cold weather. Saves 10-20 lbs depending on the battery you're replacing. All in it's less expesnive (probably) then another OEM or Group 35 battery.
We'll see how long it lasts, but initial signs are good.
I'll post the files if anyone is interested. Briefly thought about having these produced but I don't think we're going to do that. To be clear, don't print these in regular ol' PETG or whatever because it will melt.
- Andrew