heinrich

I installed an Optima years ago and it was a poor fit. I let it drain a few times and it became nreliable. Then replaced it with one from K-Mrt, Lucas iirc, and it works great.

slownrusty

Bumping this older thread, so has anyone tried a Lithium battery?

jpitman2

Auto charging systems are usually not compatible with lithium batteries. Due to weight and low self discharge they are good for standby and uses like caravans etc, but need a specific charge set up.
jp 83 Euro S AT 57k

JPTL

Aren't they highly sensitive to temperatures as well?
Personally I'd never heard of a stand-alone lithium battery application in an automotive starting system.

Antigravity

Unfortunately a lot of misinformation in the last two posts, so I will post some information on them that people can look into if they want more information..

Lithium is absolutely here for Automotive use, and it being used succesfully... we've been doing it 3 years,, and some of the higher end cars do use them. and while it is a bit more expensive they are being used all over.

We actually make some with BUILT-IN WIRELESS JUMP STARTING.... so you will never be stranded. They also weigh only about 15-16 lbs. So there are alot of people going this route... but honestly I cannot say any 928 guys have reach out to us... but we are very popular on the 911 side of things. Heres some threads.

Then we have the much smaller sizes for Racing or serious street performanc use which alot of the Mustang Guys use... but they are not a drop-in fit.k While the newer H6/Group 48 size is the exact same battery as is in the Corvette yet 30 pounds lighter and with WIRELESS built-in Jump Starting.

YOu can see it here. https://antigravitybatteries.com/products/starter-batteries/automotive


https://rennlist.com/forums/991-gt3-...riences-2.html (https://www.google.com/url?q=https:/...NOwkauh6wTiFrQ) This one is a guy recently who wanted to get some reviews on our products so members replied....

https://rennlist.com/forums/997-gt2-...t-model-2.html (https://www.google.com/url?q=https:/...zXYXjq2PlIkVEg) General Forum post when we introduced the LATEST model with the WIRELESS BUILT-IN JUMP STARTING.

https://rennlist.com/forums/991-turb...install-5.html (https://www.google.com/url?q=https:/...NN54T-3a8zS8KA) This is a great infomation thread. I explain alot about Lithium Batteries if you ever want to understand alot about them.

https://rennlist.com/forums/991-gt3-...r-2-gt3-2.html (https://www.google.com/url?q=https:/...6poQH55fZX18mg) This is the mother of all Lithium Battery threads... but 28 pages of stuff.

slownrusty

@Antigravity - Thanks for chiming in. It would be good to know if you actually have a battery that fits the 928. I'm not sure if you're familiar with the 928 battery box located in the hatch, but it is a fairly small well and the positive and negative cables do not have any slack (especially the positive) so the battery has to fit extremely well. I am happy to provide pictures if that helps. Also I'm trying to figure out if the $700-$800 for say a H6 Antigravity Lithium battery is worth the 15-lbs weight saving as I am currently running a 32lb AGM battery in my car.
Thanks,
Yasin

Antigravity

Hi Yasin. From the reference guides I've pulled the H6 should be the model and fit in there with no problem. I've actually come across some years even call for the H8 but just so you know, H5, H6, H7, and H8 are all the same in width and height and its basically the length that changes and gets longer correspondingly. Feel free to email me at chad@antigravitybatteries.com and we can confirm the details, would also love to see some pictures!. Being that you're using a very light AGM my thought is it's not a very high capacity option so we may even have some other options to explore which could drop the weight a little more even.

-Chad

slownrusty

Thanks Chad, I'll reach out via email.
Regards,
Yasin

puyi

Many thanks for all your advices Greg, but surely, don't you think that arguing like this might be counter productive...

The battery technology is so common now that it will not make a difference between a high price battery made by bosch and a distributor brand battery that is also made in the same plants as the high price bosch one!!

But, if you consider how you usually enjoy your 928, it would make a difference. As a daily car, you better choose a classic battery, but if it is a week end fun car, so you should consider the use of a battery made with calcium. It has the advantage of do not waste energy if not use (I say not use, means that the battery is disconnected from the car with the help of a discoupler for example).

No Battery will prevent you of discharge if your car has, and that is very common on our car, even a low electrical consumption.

After saying that, just take the battery in tech's of your choice and be careful of choose the battery with the original dimension.