Agreed that you get what you pay for and this battery sounds like an absolute beast. My D680 (after years of use) has performed identically to the 51R it replaced. Car starts up fine and logged Bat voltage is solid.

 

Again, glad it's working out for you. My comment is that it is not a good choice for anyone with mods on their car as you don't know when it will fail (the restart feature activities) and when it does, it will be in a high load situation which can be catastrophic to the motor.

 

Man you make it sound so scary. I'm gonna ask Heath from SakeBomb about his personal experiences since he's sold so much of these to RX-7s.

 

You would be better served by calling the technical support unit at Antigravity. They will fill you in on the issues with the ATX-30 and its use in an FD. They will also give you advice on the proper Antigravity battery for the FD. No offense to Heath or SBG, but go directly to the source for the best advice.

When my regular ATX-30 triggered the restart feature, I did not know why it was happening and I placed a call to Antigravity. That is how I learned of the issue and why I replaced the regular unit with the HD version.

Like I said - and I think Antigravity will tell you - if you are running a pretty much stock FD, you'll probably be okay, but the ATX-30 was designed for motorcycles and at best, for a 4 cylinder engine car.

 

Two of the install photos in this thread are missing covers for the positive battery terminals. That's unsafe and should fail tech inspection at any racetrack. Battery covers are cheap insurance, and I think they look nice too.
https://prowireusa.com/c-208-battery-boots.aspx

For what it's worth I think I used a regular AGM YTX-30 motorcycle battery (it might have been even smaller like a YTX-16, I didn't keep the receipt) in my mostly-stock RX7 for a while, it worked fine even sitting for weeks at a time without charging. An auto transport company left the hazard lights on for a few days and completely drained it dead. I really regret replacing that with an stock sized lead-acid battery, the damn thing leaked acid and made a mess in the poor car's engine bay.

 

That's fair and I'll probably pick one of those up. I got everything else for my install from prowire anyway. Devil's advocate though - the bin cover closes, locks, and there's nothing else in there anyway so I have to say it feels pretty safe to me.

 

Yeah, standard lead acids suck. I wouldn't put anything less than an AGM in a car I cared about. Who wants to drive around with a leaky/drippy bucket of sulfuric acid strapped to their car?

 

Yep, a fair critique. For what it is worth, I have passed tech at both VIR and Roebling Raceway with the terminals exposed as they are in the pic. I'll go ahead and take your advice though and cover the positive terminal.

 

They are covered by the bin. Same thing as a battery box. Don't think it's an issue, They are usually more worried about it being secured to the frame. Wonder if the much lighter lithium batteries require similar attachment

 

I agree, but it doesn't hurt to cover the positive terminal. I'd assume the battery being secured to the chassis is still an issue, even though it's less weight. It was pretty easy for me to install the new lithium tie-down tray where I had previously had a tie-down for my Optima.

 

Do those racing bodies not require a sealed battery box? I didn't think a battery in the passenger compartment would ever meet tech for NASA, SCCA or NHRA? Serious question because I'm looking at what I need to do to get my own car legal.

 

Well, the events that I have done at VIR and Roebling Raceway are PCA and Darkside sponsored. Neither requires a sealed battery box as part of the tech evaluation. They do require all items in the trunk or the inside of the car to be tied down or left out of the car.

I'd guess most street based cars would fail a "sealed box" criteria. My wife's Miata has the battery in the trunk and it's not sealed. It's tied down and then vented to the outside, but not sealed. Not that I would track my Audi SUV, but its setup is similar to the Miata.

 

The Miata battery is outside the passenger compartment however as it has a proper trunk separated by sheetmetal from the driver and passenger, that seems to be the differentiator at least in NHRA rules. I think my approach will be to use the spare tire well. I already have the LRB Speed sheet metal cover, use a proper gasket seal around the bottom of it and call it "sealed" from the passenger compartment, provide a vent to the underside of the car, and done.

 

I'm with jamesrterra and Scotty305, this isn't groundbreaking in any way. And still not convinced this thread isn't sponsored.

 

How is it sponsored? Just because I bought a 5lb battery that I am happy about? You must be nuts. There can't be a more high tech lightweight solution for the RX-7 for the money. My car still running perfect with the ATX30.

 

I get where you are coming from, but I really doubt someone on here with an established account is getting paid to come shill a motorcycle battery to the small audience on Rx7Club.

I say small, in a business sense relative to any of the motorcycle communities that are probably the primary audience for these batteries.

LiPo batteries aren't new, but to be fair these AG batteries seem to pack more of a punch than what has been available. As I mentioned I have been using Shorai batteries for a bit so I went back to check if they had a similar product to this AG battery. They have similar form factors but the cranking amps and capacity are at best 60% of the AGs discussed in this thread.

I don't really have a horse here. I use a stock sized AGM battery in the stock battery location. I'll be thrilled when there are affordable LiPo batteries available in common auto battery sizes though.

 

$300+ is a bit out of my budget unless it's guaranteed to last twice as long as a $150 battery, but I'm glad you guys are proving which lithium batteries work and don't work on our cars. This thread makes me want to get another YTX-30 (AGM) and mount it in the spare tire well.

 

Curious if you took my advice and called the techs directly at AG? Ask them why you should not use the ATX30 in an FD and report back. I'll repeat - the regular ATX30 is NOT the solution for the RX7.

 

you would think that basically any old car (pre smart charging/discharging, with regulator/rectifier built into alternator), from say 1980s to 2005ish, would be able to use the same basic battery provided that you don't have too many electrical demands and you can make it fit. They pretty much all work the same.

 

If you refer to "regular" batteries, I agree. If you mean any AG battery, then no, I respectfully disagree and this is based on pretty detailed conversations with the AG techies. Remember, I had the regular ATX30 installed in my car and it pretty quickly triggered the "restart" shutdown feature which takes the battery to a zero voltage state.

The point is that AG batteries - many are designed for cars like the FD - don't all work the same and this is the issue with the regular ATX30 model. The problem is that the ATX30 "smart battery management" feature which normally is a big positive is designed based on motorcycle voltage needs and demands, not a car like the FD. So, AG has programmed the battery based on motorcycle algorithms which will shut the battery down when it experiences higher than anticipated motorcycle voltage demand, like those seen in an FD with minor levels of mods. That is the issue.

The second point is that AG knows this and they do not recommend the regular ATX30. I've encouraged the OP to contact AG directly to confirm this. Just because the OP has not yet experienced an issue doesn't mean he won't under more demanding conditions. If his car has minor mods, then he's probably okay, but why take the risk? AG does have some awesome options available like the ATX30 HD - it has performed flawlessly for me - and my new favorite, the 51R series. You can install these with confidence.

 

I think we're saying the same thing. From the perspective of their original design from the factory, is there really any difference between the electrical system of a 1993 Rx-7 and a 1993 Civic or Camry? Not really, just the current demand and the location/fitment of the battery. The alternators and batteries work the same way. When you get to newer vehicles, the whole charging system is different: the way the regulator works, current sensor on the battery, that kind of thing.

A motorcycle is a different animal though. And just because you can get away with running a non lithium motorcycle battery on an FD does not mean it will work with a lithium one.

The reason why it's an important distinction is that an FD is so cramped under the hood that relocation or a smaller battery (Motorcycle battery, Miata sized battery) is common when you start modding. If you had a 1993 F-150 fitment isn't much of an issue and neither is weight.

 

Just an update, I parked my car on Saturday evening around 6:50pm or so, didn't drive it until this morning at 8:40am. Started right up and was stronger than my heavy cheap battery from Autozone.

 

Were you using a full sized (original FD size) battery before? Honestly I haven't had an issue with original sized batteries, as long as you don't get the bargain basement ones. Get the 2 or 3 year warranty ones. Smaller than original sized batteries are a different story. Having to use a trickle charger sucks.

 

Man, you are killing me. Have you called the AG techies to discuss the use of the regular ATX30 in your car? I'd at least do this so you know of the issues related to the battery's use in an FD. You can discuss with them your particular setup to confirm if they are confident you will continue to have success. As they told me, if your FD is stock or slightly modded, you will "probably" be okay. I'd also highly recommend you swap out the battery for one of the other more appropriate AG batteries as being safer is never a bad thing.

 

Yes, I was using a OEM replacement battery. I replaced it really because the ATX-30 seemed to me like a bargain for $395 and saved me what 35lbs or so for the money. I was pleasantly surprised with stronger starts with this tiny battery.