Does anyone have experience with Li-Fe ion battery replacement, instead of the usual Lead Acid battery? Is it a better alternative? Thanks.

Car is 2002 996tt

 

Just get a good quality AGM battery. My two cents...

 

Some have used antigravity. It has an emergency start feature, which is cool. You’ll lose 35lbs or more of weight in the process, and that weight sits a bit high on the car.

 

I have an Antigravity battery. It's expensive, but I like it. Very light and well made.
Capacity is a little lower, but with the car sitting unlocked (not low power mode) over the winter (approx. 50F in the garage the whole time), it sat for about a month before the battery went into sleep mode. Push button on fob, it wakes, car started right up.
Usually I keep it on the charger though, that was just a test.

Edit: Antigravity posts alot around the forum, and I think does a good job of posting technical battery information without pushing their own products too hard. If you search for their post, you'll find a lot of discussions about battery options. Not just theirs.

 

I concur.

 

My lead battery lasted exactly 4 years. Just switched to an AGM.