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

[Wild Turkey]

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.)

Battery bar 31512-SL0-010 to save a pound (51R battery)

Battery bar was rusted so I drafted this up; it saves a pound as well. It also avoids the problem with the OEM battery bar shorting out the terminals if the insulation fails (which it will.) Note that different NSX's have different sizes of batteries so you may need to scale this up or down...

www.nsxprime.com

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:

 

[FlopShot]

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.

 

[Ace3]

Lol feel exactly the same way!

 

[AvroPac]

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

 

[Wild Turkey]

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.

 

[Wild Turkey]

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.

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.

 

[Wild Turkey]

OK @Matt11212 , files for printing are uploaded to Thingiverse:

NSX Battery bar, 51R or AntiGravity ATX by Pi-design

If your battery bar is rusty, print this to replace it.AntigravityPrint holder along with 2 spherical holders. There are 2 options for the spherical holders depending on which J-rods you have and which battery plate (91-96 or 97-05). Print with front face down.51R (Zanardi)- battery bar 5When...

www.thingiverse.com

 

[Wild Turkey]

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.


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.