khooni

anyone heard of these?

Yargk

I have, but no experience. Li battery prices have been coming down steadily for years, in general. Yet companies like Braille have kept prices in the $1500 range for their automotive batteries, which is insane. The RS-20 is the first Li auto battery I've seen with a reasonable price, $600, and great capacity. Only 10 pounds. It's got to become a good seller, for what it is. I'm waiting for people to run them for a while and see what the longevity is like. Antigravity batteries seem to be relatively well respected in the motorcycle world.

Accel Junky

I'm a fan of Shorai LiFePo batteries as they are just as light of not lighter and much more affordable. Problem is the biggest battery they sell is 36ah which I do not think is doable in a GT3. You could run 2 in parallel as they told me some NASCAR clients do. That would be 10lbs for 72ah. I've run the 36ah model in several street cars with no issues but you must only crank and not sit with electronics on. Also when the weather gets near freezing you will have very weak starts so I swap out with OE in the winter.

Sword_of_the_Spirit

Look into EarthX. Their 24c is giving no issue to my 993.

MC 968CS

Yes. Had one from AntiGravity for a year in car - no issues.

Tip....Just never let them go flat - I use a Lion trickle charger when car is just sitting around for a while

Yargk

Thanks for the info. What is the use of the car if you don't mind me asking? (street miles vs. track)

khooni

FYI stock lithium porsche battery is only 18Ah for 997.2 gt3

what are you talking about?

Accel Junky

I'm speaking from experience running a 36ah LiFePo battery in daily driven cars (in about 5 different cars now) with smaller engines and nothing that runs when you turn the car off. I wouldn't trust what I run in my GT3 without more capacity.

My comment was specific to the inexpensive Shorai alternatives. Please read more carefully.

Also, the OEM lithium battery is Lithium Ion and its nominal output is not directly comparable to lithium iron phosphate or regular agm batteries.

khooni

I have the stock lithium ion battery and it is made with lithium iron phosphate cells with rated capacity of 18Ah............

what you said is simply incorrect.

Fisher

http://press.porsche.com/news/release.php?id=510

"The new lithium-ion battery will be available as an option as of January 2010 for the 911 GT3, 911 GT3 RS, and Boxster Spyder and is delivered with the car. It is priced at $1,700."

"The lithium-ion battery being introduced by Porsche as the pioneer in this area is made up of wound film of carbon and iron phosphate with a ceramic film moisturized by the electrolyte that serves as a separating layer in between. Compared with other types of lithium-ion batteries that use a combination of manganese oxide, cobalt oxide or nickel, this lithium-iron-phosphate battery, as it is called, offers advantages when used as a starter battery. It is robust and consistently guarantees the usual voltage of 12 V for the car's on-board network."

bittrl1000

Lithium Iron Phosphate is generally discussed as a type of Lithium Ion.

Marine Blue

I have been using an Odyssey AGM for the past year without a single hiccup. No special chargers needed, rennline makes a great mounting kit and about 15 lb weight reduction.

Here's a link with the install: https://rennlist.com/forums/987-981-...w-weights.html

modoz61

There are a range of features with LiOn(Po) batteries that are all attractive

Understanding your batteries operation is critical, as mentioned earlier keeping them on a trickle charger/maintainer is critical (unless its a daily driver)

If these batteries lose too much charge they may need to be returned to the manufacturer for recovery.

The Porsche Lithium battery (and some of the others I am led to believe) have protection circuits in them that cut out if the charge gets too low preventing them from collapsing

One of the great features of these batteries is that they can give nearly 100% of their stored energy. However if they give too much and you try to excite the cells by charging this can cause a cell short that will then cause a battery failure. And then 100% of their energy will feed the fault.

I've lived through a failure and I can assure you that there is nothing great about knowing you have a battery exploding due to this occurring, sitting mounted in the car above the fuel tank. Thankfully removed the battery through acrid smoke and placed outside where it continued to smoke, crackle and pop for a further 3 hours. The heat sufficient to require respray work due to paint blistering.

Great batteries but follow your manufacturers guidelines as they are not the same as a Lead Acid or Gel type.

wolf505

I picked one up of this RS-20, they have an $ 400 special what was just too good to pass. I will report back once installed and tested.

32krazy!

i have a voltphreaks vph-900 for sale with charger if anyone is looking for a great battery at a great price