asellus

Yeesh, 30ah.

Better hope it starts on that first crank.

blackcheetah

The car will start anytime just dont listen to radio 1hr when car is shut down ...

DaveGee

How much did that weight savings cost you?

DaveGee

asellus

don't forget to plug your car in when you park, either...

there's a lot of literature and warning from AG about this, and it's apparently so much of a problem that they embedded in that whole "restart" integrated jump pack for when the battery dies from parasitic discharge

like I said, it's racecar stuff, not DD/WW stuff.

Imola02

I have a newer to me 2013 and just checked the battery date the other day. 3.13 date code. Find it unbelievable it still holds a charge, says something about the longetivity for sure. I figured since it was a CPO car that it would have been a newer battery.

blackcheetah

Hmmm ok thx i will check that can you share some source? in my 996tt the battery lasted but died cuz what killz the battery is if is drained below 10 volts you have to be very careful yes this battery is not for everyone only race purpose

Sarawnty

Is the ATX-20-HD the correct model for a 2018 991.2 T? Thx!

PTS-BRG

When I had my 991.2 I was on the fence for over a year about paying the premium for the lithium battery. After I bought it I was glad I did. The weight savings is certainly crazy. but the cranking power far exceeded the factory battery and I cannot tell you how many times the jump start feature saved my ***. The key fob has a button to access a reserve so if the car dies you just push the button and the car starts. If you ever had a factory battery die while the car is locked you know what I am talking about ..

TimboCarrera

I'm about 1 year into the anti-gravity for the 991.2. I got the bigger amp. Customer service is great. I also purchased the bluetooth moniter. I run lithium in motorcycles and rc planes and helis. This was a comfortable move for me. I've used multiple chargers over the years and get identical results as my li-fe or pb units. No not with li-po which anti-gravity is not. I can't remember any of my bikes and so far this unit ever needing a charge. Wifes bike sits for months. I do drive normally at least once a week in the 911, garaged and warmer climate. I did park outside a couple of times in the 20's just to test. 911 started fine. Everything worked better after installing the anti-gravity but perhaps my orginal battery was tired. The only issue I had was the bottom side mounting bolt was short by a thread or two. I think I bought a longer one at autozone for a buck. Now if I lose 40 lbs I might feel the difference in weight.

mc3456

Your logic makes sense, but in reality, it may be slightly off. Reason I say that is I bought a 2015 M3 which came with a Lithium battery. Sat in the showroom mistakenly plugged into a regular showroom charger for a lead acid battery. Day after delivery, battery was dead...as in completely dead, ruined, kaput. Dealership paid for a new battery. Incorrect chargers are well known to kill Lithium batteries, so for the $95 it costs for a proper Lithium battery charger model (Ctek), I wouldn't F around with a $1,000 battery just to save a few bucks. YMMV.

quattrospeed

This is funny... I too bought, and still own, a 2015 M3, and it came with a lithium battery... I purchased it new, but mine was in the showroom plugged into the wrong charger... 2 years later, I had to replace the battery and it cost me over 3800.

mc3456

I suspect a bunch M3 batteries were ruined by clueless showroom staff. 😂

fsmich

Having the car coded for a lithium battery definitely changes the alternator charging profile. I bought the 30ah antigravity battery in 2018, and after a few months began getting "electrical gremlins" - rws fault, ok to drive, etc. The car would always be at 15.0-15.1 volts charging, even after coming off the cetek lithium charger, and fully charged.

Antigravity took the battery back, and replaced it with the 40ah version (highly recommended). Since I was still always getting the 15.0v charging from the car, I had my indy program the car to lithium. Now the car slowly ramps the voltage up, from 14.3 to about 14.7, then back to 14.3 when the battery is fully charged. I haven't cetek charged the battery in 2yrs, driving the car for 20 min once a week is enough to keep it fully charged.

z168

Holy cow $3800 for a battery?!

Maybe in time this will get cheaper

4 Point 0

8 months


I’ve had this one for about 8 months. Zero issues. Never needed a charger. I sometimes go 3 weeks without driving.
No problems.