Save another pound: Ultra lightweight AntiGravity battery mount (or other LiFePO4)

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11 January 2021
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Ontario, Canada
For battery weight, it's probably fair to consider the weight of the battery holder as well. I decided to design my own ultralight battery mount for the AntiGravity ATX-30RS, like my previous PET-G battery bar for the 51R (Zanardi) battery, which saves an additional pound over the 9 lb savings with the 51R battery (and avoids the shorting battery bar problem that @centerpunch noted.)

The AntiGravity ATX-30RS battery is only 6 lbs. There are several mounts available, from AntiGravity, Grey market, etc. but they're all over 1 lb, and all seem to need new holes drilled.

This battery bar holds the ATX-30RS battery using the OEM "J" rods and is only ~0.3 lb total, with the rods. Because the battery is narrow compared to the standard batteries, the bolts need to angle "wider" and need gimbals to allow a secure mount. I took some pics without the electrical connections to make it easier to see (Polarity is wrong, but I wanted to show the AntiGravity stickers.) There is some allowance in the gimbals to allow someone to go to the ATX-20RS if they really want to go crazy. Note that this is the 1997+ battery tray:
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Very cool, wish you had designed this before I dropped $250 on the GreyMarkt mount. lol. Also wonder if your mount will work on the early model tray, since the J-hook is positioned differently.
 
That looks great!
I’ll be sending you a PM when I’m allowed to for the file. Just received my ATX-30 after my previous battery gave up the ghost. I will be happy to check fitment on the early battery tray.
I have a ‘91
 
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Very cool, wish you had designed this before I dropped $250 on the GreyMarkt mount. lol. Also wonder if your mount will work on the early model tray, since the J-hook is positioned differently.
Thanks! I allowed ~30 degrees of mobility on the gimbals to allow for the other location of the J-rod slots on the 90-96 NSX's, as well as the ATX-20 if someone was even more of a weight weenie. I'll double check this shortly and update. I was wondering if they'd work on an S2000 - I'll try to check that as well.

Maybe I should get into the battery mount business. I could make them for 1/2 the price and 1/4 the weight. :) Hmmm. Better stick to my day job.
 
I thought that I had accounted for the 90-96 battery tray differences, but I wanted to double check. I checked on a 95 with an original 90-96 battery tray. It works perfectly.
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From the earlier pictures, it appeared that the J-rods would not be long enough to reach the original battery tray slots (which are level with the bottom of the battery), but I think this is because those are 1997+ J-rods, (31513SL4000 bolt, battery setting, 220 mm) that fit the 1997+ battery tray.

The J-rods that were originally in my 1995 are about 2 cm longer, and work perfectly with the 90-96 battery tray and this mount as shown in the pics. Hard to tell from the parts diagrams but perhaps 31513SB2000 (bolt, battery setting, which doesn't give a length)? 31513SR3000 is for the NSX-R I believe, and is clearly shorter.

It also looks like I could make the shorter J-rods work as well by making the gimbal a little shorter. I'll draft up a shorter gimbal as well. I also had a look at an S2000. That battery bar goes straight over the top, so this won't work.
 
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OK @Matt11212 , files for printing are uploaded to Thingiverse:
 
How I recommend installing it, with an easy battery shut-off if you're going to store it for a while, but with a direct charger connection to the battery. This thing spins the starter like it's on crack.
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Note: I swapped the side stickers around for aesthetics. Be very careful about the polarity. I 3D printed red and black caps for the terminals for extra clarity.
 
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