Just wanted to give my input on one of the best purchases ever for my FD3S. Don't you hate it when you get caught off guard with a dead or weak battery? I know I hate it. Well being that my car is 26 years old I decided to spoil it and buy a bunch of upgrades for it from Sakebomb Garage. One of the best purchases I have ever made in terms of value and convenience.

I bought a Antigravity RTX-30 battery because it appealed to me in two categories. Practicality and performance. The cranking amps is rated at 880 which is higher than most standard batteries to start a FD. More cranking amps will start the FD3S better, especially older models. Also the weight savings is so significant. I saved 32lbs on front end weight by replacing the heavy old battery, the RTX-30 weighs only 5.75lbs!!! I can hold the entire car battery with my arm extended out. The cost isn't anything crazy either, at $395 that really isn't bad when you compare it to a Optima battery that is way bigger and heavier. The other bonus is the Restart technology, if you ever get caught with a dead battery because you left on the lights or something all you have to do is press the restart button and it access a reserved capacity that can restart your car to recharge the battery again. Genius!!

I also bought the billet battery tray to mount the battery to the front of the car where the old battery was. It is a universal tray, not FD3S specific. So my recommendation to Sakebomb is that they should build a FD3S specific battery mount and I would gladly pay more for a plug 'n play fitment. The universal battery tray to install it you'll have to make your own holes to mount it unfortunately.

Let me know if you guys have questions about this. I highly recommend Heath and his team at Sakebomb Garage.

 

Very cool! The only thing that concerns me is I believe this is a motorcycle battery and as far as I know not ment to be used in a car. Not sure what the draw backs are though. I've been looking at Antigravites automotive restart line to replace my current battery. About double the price though.

 

Doubt I’ll be in the market for that battery, but I’m a repeat customer and second the quality and service from Sakebomb.

 

Man the prices on those batteries are getting SO tempting! Love that weight savings!

Would be interested to hear how it works for you long term as well.

Dale

 

Same concern with the size. I did order their 51R size with remote controlled re-start, it's forever backlogged and after months waiting they cancelled my order so... staying with a ol' regular agm 51R in the trunk for now.

 

I have read a few articles that describe lithium as a great alternative for race cars but not a god option for weekend driver use. Sometimes about our alternators no providing the right type of charging. I am a little concerned that I would get stuck somewhere stupid lol. However. I ran a surakarta gold agm motorcycle battery for 3 years without an issue. It was $110 and weighs the same. I am not trying to know anyone paying extra for awesome technology. And I’m sure the lithium side of the coin has many benefits. But knowing that I was able to run smoothly on my cheap AutoZone battery made for a big bike, I don’t think I’ll be shelling out the extra cash for one

 

I've been daily driving my car with this battery for two months now. It starts stronger than my standard battery *Interstate* that was in it before. I also have a double din Apple CarPlay stereo, big 6x9s and a JL Audio amp, no issues running all this. Cranking amps is higher compared to the 500+/- of the Interstate I think. I have yet have a problem with this setup. I've even parked it for 3-4 days with the alarm on and it started right up after my trip. I'll follow up with this post in a couple months just to let people know how it goes. But I'm telling you the weight savings is tremendous and the performance of the battery itself makes it worth $399!!

 

I have one of these on my Yamaha Super Tenere. Worth every penny.

 

I got the ATX-30HD for the higher Amp Hours. No complaints and have a good overview in my build thread.

 

One more advantage, it's only 4" on its narrowest dimensions. You can lay it flat inside your spare tire well if you wanted to relocate it in the cabin.

I didn't want to cut up my bins, so this was quite the elegant solution.

 

Thanks for the review. This definitely looks interesting. Do you happen to know the amount of lifetime this battery is supposed to last?

 

You can go to the website and read the FAQ. They give a broad answer of about 5 years life. https://antigravitybatteries.com/hel...m-battery-info

It looks like they have a built in micro controller to manage voltage and state of charge. So I'd think with an Rx-7 charging system it would be especially straightforward, as these older cars don't have any kind of smart charging built in. The alternator just generates whatever juice it can based on engine/pulley speed, and the control module on the battery will regulate how much charging happens. Newer cars will basically throttle the alternator based on battery state of charge and to optimize fuel consumption by doing charging more during deceleration.

I don't see any reason why these would have any particular issues as long as you operate it as designed. That means no parasitic draws for example and no abusive charge/discharge cycles. It's basically a scaled down, simplified version of the battery you might find in a mild hybrid like a newer Ram truck.

 

Clicked on thread out of curiosity because I've been a consumer of LW batteries for years. To my dismay I found a glorified sales pitch meant for the 'fannies' instead and the way in which it was written actually makes me consider if this were sponsored in some way as I find gushing over a battery very hard to believe.

I think Jamesrterra stated his experience well and there's many other shops out there to support besides SB imo.

 

Glad the OP is happy with his experience to date with the ATX-30. However, I highly recommend against the use of this particular battery unless your FD is stock only. This is why I use the HD version of the battery and if I were to do it all over again, I'd go with the Antigravity 51R model.

In short - the ATX-30 is designed for motorcycle use. Note you can find the battery under "Motorcycles" - https://antigravitybatteries.com/pro...s/restart-oem/

Why is this important? Because the ATX30 is a motorcycle intended battery, its RE-START feature uses algorithms for the battery that are programmed to monitor and control motorcycle levels of voltage and draws. This is why the RE-START feature activates at a much higher voltage level (12.45 - 12.8) than what would be intended for a car. Because the battery's RE-START feature was not intended for car use, especially in cars like ours, it can have adverse effects under operating conditions for any device that draws directly from the car battery. For example, think about that second fuel pump you have wired to the battery or maybe your aftermarket ECU. When the second fuel pump activates, on most of our cars it will draw directly from the battery and most likely trigger the RE-START feature. That can have significant adverse results as the battery provides ZERO power when the RE-START feature is triggered. You have to press the RE-START button on the top of the battery to reset the battery to normal operation.

So, why then does the ATX30 HD work on the RX7? While it too is a motorcycle battery, it was developed for use on Harley V-Twins that need much higher voltage and AMP draws. Thus, the ATX30 HD is a better fit, as it draws much deeper than the ATX30 while allowing your components connected to the battery to properly operate.

But don't believe me, call Antigravity directly and ask them. They will tell you that they have had numerous reports of problems with cars attempting to use the regular ATX30, in contrast to much success with the ATX30 HD on cars like ours, Supras, and high-performance V8s. This is why I swapped out my ATX30 for the HD version and it's working like a champ for me.

If you really want to keep the RE-START function, but on a battery designed specifically for automobiles, check out the Antigravity Group-51R Car Battery:

https://antigravitybatteries.com/pro...ive/ag-51r-rs/

It comes with a RE-START function that was developed for automobiles and also offers a cool Battery Management System (BMS). It does though cost more ($660) and weighs 8.5 lbs. versus 7.6 for the ATX30 HD. Both the ATX HD and the 51R would be good choices IMO.

Second, most of Antigravity's batteries, including the ATX-30 HD, have an integrated battery management system (BMS) built-in. The purpose of this system is to prevent improper discharge and charge situations. But don't take it from me, call Antigravity directly and they will confirm.

So, if one is going to use a battery not designed for automotive applications, the recommended battery for the FD is the ATX-30 HD, not the regular ATX-30. It contains the above referenced BMS to protect against unregulated recharge problems and also avoids the issues caused by the regular ATX-30 restart, motorcycle designed feature. Again, this technology is not designed or calibrated for use in a car and in particular, a modified FD.

Third, Antirgravity offers two different billet style mounts that work great for the FD. I use this one:

https://antigravitybatteries.com/pro...y-tray-lc-fab/

To the OP - Antigravity has an upgrade policy where you can return your battery and upgrade it to one that is more appropriate for use in an FD. Like you, I originally installed the regular ATX-30 only to have immediate issues as my car is heavily modded. Antigravity replaced the battery for me at the cost difference between the regular and HD model.

 

yeah I was a little confused because the cost you guys were talking about was like $300 range and I dug into the anti gravity website and it seemed more like the appropriate one would be the $600 one. I see now that there are multiple products here and running a straight up motorcycle battery may not be the best option. I don't have any firsthand experience with AntiGravity batteries, but I do know enough about lithium ion batteries in automotive applications to see that there is no inherent problem with using them as long as you have a control module on the battery.

 

It is a bit confusing, but you are correct, the best one - if you want to go the ultra-light route - is the ATX30-HD, not the regular version.

The big issue with the ATX30 regular version is the control module algorithms that are designed for motorcycles, not cars. This is an inherent problem when trying to use on an FD, as the battery will shut down the car via the "Restart" feature and this can happen at any time when the battery senses a "large" draw occurring. Obviously, cars have larger draws than motorcycles, and modded FDs are an even bigger problem. Think about it. For example, you are out on track and your second fuel pump kicks on, triggering the "Restart" shutdown feature which shuts your car down because the battery drops to 0 voltages when this happens. And given the way our cars draw power, I can think of numerous scenarios like this.

Because of this potential issue, Antigravity highly recommends against the use of the regular ATX30 in FDs. I alerted SakeBomb to this issue via their GB thread and would encourage them to stop selling the regular ATX30 to FD owners. There are so many other Antigravity battery options now that it just makes better sense to go in another direction.

My picks - 1) the ATX30-HD which features 970 CCAs, low weight (7.81 lbs.), and a battery management system but no 'Restart" feature or 2) the 51-R-30-RS featuring 1200 CCAs, 11.7 lbs., the "Restart" feature, and a battery management system. Both of these batteries solve the problem of using the ATX30 in an FD and offer great weight savings and technology features not found on regular car batteries.

 

For what it is worth, I have been using a Shorai LiPo battery on my old Honda motorcycle for like 7 years now. Thing still works like a champ and I don't think I have ever had to top it off with a trickle charger despite the bike sitting around quite a bit.

If the onboard battery controller can deal with that bike's highly sophisticated 1980s charging technology then I wouldn't have a lot of concerns using an appropriately sized battery in my FD.

The reservations you may want to have are if you live/drive in a very cold environment (lithium batteries have a specific startup procedure in these conditions) or if your FD has a parasitic draw on the battery (a concern for any smaller capacity than OEM battery really).

 

AG's really getting some free advertisement right here. Never knew members needed to hold hands as they read product descriptions.

 

To be fair, a lithium ion battery is more complex to manage than a lead acid battery, hence the control module on some implementations. Combine that with the fact that some people want as small/light a battery as possible and others just want a modern replacement for the original factory sized battery.

 

I wasn't gonna comment to keep this thread clean, but looks like that time has come and gone.

So we're talking $400 for a questionable battery (maybe upwards of $600!? for the correct battery) and then another $200 for a tray that isn't even made for the car?

Maybe a decent compromise of weight/cost/robustness would be the Elite Rotary tray with XS Power D680 which is an AGM deep cycle. That's $300 all-in for that setup and it's about 15lb compared to 30lb for a 51R or 50lb-ish for the stock size.

 

If you don't overcharge or drain them, they are probably fine

That said, nothing beats throwing a miata battery in the bin.

.

 

You are close on your statements. For the correct battery, it's $599 for the ATX30-HD and then $110 for the billet battery tray. So, a total of around $710. The tray fits very well so I would recommend it for the FD as the footprint of the battery is only 6.5" X 5". That's tiny and is easily installed in the FD. Here is a shot of my setup with the tray:


For comparison, the Optima yellow top (43.5 lbs.) I replaced just barely slid into the opening and that was with some effort.

The XS Power D680 is a 320 CCA battery with a 28-minute reserve versus the Anitgravity ATX3--HD ratings of 970 Cranking Amps (3X more) and 48 amp hours of reserve (almost 2X more). Plus, the D680 weighs 15.4 lbs. versus 7.81 lbs. for the ATX30-HD, or almost twice as much. So yes, you can spend less for a lesser battery but if it were me, I'd be very concerned about the 320 CCA rating of the D680. That's really low for use in an FD. An equivalent Optima yellow top is 750 CCA.

 

I did this once in my car's life but was concerned that the Miata battery is "open" to the atmosphere and I didn't want any fumes in the car. That's why you need to go at a minimum with an AGM-based battery.

 

Here's my setup.

• Antigravity ATX30-HD Battery
• Zprecision Battery Relocation Bracket (excellent fit and finish)
• MSEL Solid State Battery Isolator

Expensive? Yes. But I don't have to think about it anymore.

 

Guys the battery is $395, still zero problems since they day I installed it. My car has an alarm system, Power FC and a stereo system. Zero problems and its been a couple months now.

https://www.sakebombgarage.com/antig...start-battery/