Yargk

There's a group buy brewing for Lithium batteries for 991 GT3s. Should fit GT4s the same. 11.5 pound battery, 30 Ah Lithium (50 Ah Pb-acid equiv.). $700 normal price, I assume less for the group buy. I have no affiliation besides that I know lithium prices have been coming down for years and they shouldn't cost what a lot of other companies charge and have charged for years ($1500-$2000, yikes!).

https://rennlist.com/forums/991-gt3-...for-2-gt3.html

digitalrurouni

I would be in. Looks like it would be great for my Spyder.

d00d

A lighter alternative is the EarthX ETX1200 (6.9 pound, 25Ah, $725);
https://earthxbatteries.com/shop/etx1200
https://rennlist.com/forums/gt4/9321...l#post14689773

digitalrurouni

Wow nice! Love what you have done with the GT4!

Diablo Dude

Your battery set-up looks super clean and light!
And $1000 cheaper than some of the other products in the market place.

GrantG

Anti-Gravity will also have some smaller/lighter versions available (with less capacity)

Diablo Dude

Saving 40 lbs. with a Lithium Battery that has BMS sounds like a no-brainer.
I'm interested.

https://shop.antigravitybatteries.co...omotive/rs-30/

G-forceGT4

Antigravity has a lower amp hour than their RS30 50amp hr. One of the members has been using it & it's about 1/2 the weight as well. The Antigravity batteries have a great feature where they turn off automatically if they're discharged to low, yet can be reactivate if & start the car if required (so you're never left stranded with a dead battery). I'm interested in the group buy as well.

Hams955

I reached out to them. They are working on a mounting bracket for the cars to mount the RS-30. I told them I was in for one on my cars when they do. The battery dimensions won't work with the Rennline battery mounts designed to use the Odyssey 680.

- Chris.

digitalrurouni

Can't wait! Definitely looking forward to ordering one.

Antigravity

Hi all this is Scott from Antigravity Batteries and we will be doing the GROUP BUY.... I'll post some details later here as we get finalized pricing, but yes it will fit the GT 4 as well as any other Porsche that has the battery that is called an H6 and also known as a Group 48.

I noticed d00d made a post about the EarthX battery being a lighter battery. First off EarthX make a fine battery.... but that battery that is mentioned in not in the same league as the RS-30 The RS-30 has many more Amp Hours, more Power, a much more sophisticated and better Battery Management System, it has our RE-START feature that would never leave you stranded with a dead battery, and it's built to fit and work in anything from Daily Drivers to Race Automobiles. So I just want to make sure that you consider Apples to Apples comparisons.... and the RS-30 is in another league compared to the EarthX shown above. But we also offer those Smaller Versions such as the EarthX and they are hundreds cheaper, yet still have our RE-START feature and a more sophisticated BMS than the EarthX battery.

If you looking for something that's Smaller or Lighter we also makes those sizes and in many different options and sizes at a lower cost yet still offering more that our competitors. Those are our Antigravity models that are better compared to the mentioned EarthX since they are the smaller lighter models we offer. But most our smaller model also offer our RE-START feature which mean the battery won't ever leave you stranded. You can see all the different types of Batteries we offer here.. Antigravity Batteries.

But the size you should choose depends on your application. You don't want too small of a battery if you are doing mostly street, or store your vehicle... so you have to weigh what you want to do and get out of the battery.

If you want a bunch of information on Lithium, I was on another thread located here.... https://rennlist.com/forums/991-gt3-gt3rs-and-911r/1063206-light-weight-battery-for-2-gt3.html where I explain alot about many aspects of it.

IF you have any questions let me know.

digitalrurouni

Only question I have is when is the group buy happening? My body is ready!

d00d

Thanks Scott, I like how you make an automotive bracket available, and don't make me search for one.
The EarthX ETX1200 is 24.8Ah (1C rate), and the Antigravity RS-30 is 30Ah (50Ah PbEq*) *but Cranking Performance better than a 90Ah Lead Battery, is 1C rate equivalent to PbEq?
ETX1200 is 1200/600 (PCA/CCA) and RS-30 is 1200 CA, are these the same?

Antigravity

Basically when I say 1200 cranking amps that's the pulse discharge... But honestly the testing procedures nowadays for this are based on electronic resistance test and I don't consider it completely accurate. The best testing is a direct a load on the battery but most companies aren't doing that, so they just get a best estimate of the cranking ability with the electronic tester.

The way that we personally like to do it is by testing in highly built motors like 900 to 1200 hp V8 motors....IF it flipping that then we are good on our larger Batteries. And within that power of a lithium battery it does depend on the C-Rate capability of the battery cell itself. The C rate of a battery is basically how much energy it can discharge and how quickly... So I can have a 15 amp hour battery with a 20 C rate cells or have a 15Amp hour battery with a 40 C rate in the 40 C rate will be a more powerful battery so depends overall on the cells and a larger Ah battery pack will have more Amp hour capacity and power. Like cubic inches in a hot rod... it's bigger it more powerful. So a smaller cell pack with less capacity (amp hours) will have a lower power rating than a larger cell pack with a higher amp hour rating it just because the energy density of lithium battery cells, So REAL Amp hours are the most important consideration if you want more power or more capacity. But also the battery starts to weigh more...

So we do throw out the electronic test rating.. but it actually more that 1200 but I think it would be not effective to say it has more that that... so it's and average and what I feel is safe to say and have it blow people away with its power.

khooni

Just read on the gt3 page.
I have the Porsche lithium battery for the gt4 and have the piwis configured for lithium battery

Presumably I don't have to change it back to normal battery?
Also will the setup with mounting tray for gt3 work on gt4?

Also, I'm based in the UK and would like to join this group buy (including shipping to uk)

Tx