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Title says it all. Car is cranking in the low 11's and mid 13's when running.
Because nothing can ever be stock I am looking at batteries. I have had an Antigravity before in my Mustang but I do not remember it being $1000!
That got me looking for other options, came across Powertex and they seem to have decent reviews. It would be about a 26lbs weight savings right on the nose of the car. Anyone running one of these? It still isn't cheap at $750 so about $550 more than a OEM battery.
On the fence, anyone know of any light weight batteries but in the sub $500 range?
Last edited by Street_Carver; Dec 5, 2025 at 12:41 PM.
Yes. I ear marked a thread and put this in my amazon shopping lists from people here on the forum. Its a lithium battery most likely made in china, ,but the thread said they worked well. Give some research. They are like $300
Once my warranty is gone, will replace with a lithium or any light weight variant battery. Cant go wrong with the antigravity battery if keeping the car.
Great find! This is exactly why I came to the forum. Sadly they are all prob made in china so why not just take the best deal! I'll take 5LBS more for $400+ less.
Curious to hear from folks who have done the swap. The C8 charging system is designed under most conditions to charge a Lead Acid battery to 80% capacity. Per chart below that is 12.42 volts. My 4 year experiance is that is where it charges.
My E-Ray that comes with a Li-Ion battery comes with a charging algorithm that charges that battery to 13.3 volts. That is ~80%. Both done to save energy. For the Li-Ion battery it also increases the battery life.
So will the C8 charge the Li-Ion to about 12.42 volts? That is only about a 20% charge. Now unlike Lead Acid Batteries where 20% charge is a weak level to start the car. With a 20% charge in a Li-Ion battery will start the car fine. But it's getting pretty low and not good for the battery to only stay charged to that % capacity level.
Note, switching to an AGM battery although only charged about 75% that is not a big deal. Although not the using all it can do. I swapped my 2014 C7 Lead Acid with an AGM and it worked fine.
Need a Battery: Powertex Vs Antigravity
