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New Lightweight Battery Installed

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Hello all, I installed a new lithium battery today. I can't say much about how good it is yet. I can say that it starts the GT3 no problem.

The OEM battery weighed in at about 42.5 pounds.

The Lithium battery weighed in at just under 6 pounds.

Very nice weight savings. :)

I had the battery custom built by a guy at Lithiummoto.com.

The guy is very knowledgable and helpful. His prices are much better than the big brands. The battery was $600. As you can see by the pics, he hand builds these batteries. So if pretty is your thing, then you might not like his stuff.

I know what a lot of you are going to say about taking a chance on an unproven battery manufacturer. I have done my research and I know a good bit about batteries so I am will to take the risk.

I will keep updating this post as I get more time and miles on it so everyone will be able to follow it's reliability.




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Yes, I checked it while it was running and it was maintaining 14.5 volts. With the car off it was holding 13.5 volts. Lithium batteries charge much quicker than lead and they hold a higher voltage too. The only problem with a battery this small is that you will need to keep it on a battery maintainer if the car is stored for more than a few days because it doesn't have the reserve capacity of the large lead battery.

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Yep. The Porsche battery is very nice in every way but it's not $2800's nice. It also weighs 12 pounds. The next cheapest lithium battery I found that would start my GT3 is $1050. It has a prettier package but it does exactly the same thing.

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  • 11 months later...

Hello Aehsani,

The first year with the lithium has been trouble free. It has performed perfectly. The only thing I have done special is have it on a battery tender if I'm not going to drive it for a week or more. I have let it sit for about 10 days one time without the tender and it still started just fine. I would say in warm weather it actually starts the car better than the stock lead/acid battery. In cold weather it seems a little weak but it still starts the car. In the cold these batteries require some heat. But all you have to do is turn your lights on or try to start the car and it will generate its own heat. Once it is warm it starts just like on a warm summer day.

With all that said, I'm very happy with the battery and would recommend it to anyone looking for a (cheaper) lightweight battery option.


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Thanks for the very info. It certainly was very usesful. A couple of furhter questions:

When you say cold what temperature are you referring to?

You mention turning the "light on" would facilitate to start the car. I presume the headlights; correct?

Thanks again for the helpful info


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Hi Ali,

When I say cold I'm talking around 40-45 F or lower. These lower temps are a problem with small lightweight batteries of any kind. I'm sure you have noticed even with your stock battery, the car will turn over slower in the winter. The difference is that the stock battery has more reserve capacity to make up for being weak in the cold. Small lithuim batteries need a little help. You have to make them active again. I'm not the best at explaining this but when you put a large amperage draw on them it activates the ions within the battery. This makes the battery heat up. I don't know if you use cordless power tools but if you use a battery powered drill, you will notice the battery getting warm as you use it. This is from it having to work while it is discharging. The same thing happens with the car battery.

So by turning on the headlights for about 30 seconds it will warm itself up to operating temp. The same can be done by just turning the engine over. The car may not crank the first time if it is cold but that draw from trying to start will activate the battery and cause it to heat up. Then you wait about 15 to 30 seconds between trying to crank it again. The second time the car should crank normally. I don't like the second method as much but you have to do what it takes. The main thing is that it takes a fairly large amperage draw to cause it to heat up. Thus you need to use the headlights or the starter to get the job done. Now those are the methods for heating it up but honestly I have never had to do either. I started mine about 3 weeks ago at 45 f and it turned over the first time, a bit slow but it still started right up.

With all of that said, I can't say how well it will work below freezing. I see you are in St. Louis. I don't drive my car when it is that cold so I can't say how well it would work. I would think you might need a slightly larger lithium battery if you are going to use it below freezing temps or just put your stock battery back in during the winter months. I hope I have helped and didn't confuse you. LOL

Have a good holiday.


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Thanks for the elaborate description and the tidbits to restore the battery function. It was most hepful. I installed an Optima battery in my 05 GT3 last year. My only concern is whether the lithium battery will still have enough rerserve in 25-35 F degree-temperatures.

Thanks again.


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Your welcome and glad I could help. Like I said, I don't have any experience with temps below freezing but I've been told it shouldn't be a problem. Again, if it were me I would use a slightly oversized lithium or the Optima at those temps. You could ask the guy at Lithiummoto or you could look at Antigravitybatteries.com. They have a 720 amp lithium for about the same price as my 600 amp. When I talked to the guy at lithiummoto I asked him about making me a larger one. He didn't think I needed it and told me that the 600 amp battery is all I would ever never need and at this point I tend to believe him.

Good luck and take care.


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I've used several of these type of batteries on my dual sport and off road moto's. Fantastic performance with very few downsides.

Just to clarify, these are not really "lithium" batteries. They are "Lithium Iron Phosphate", specifically LiFePO4. They are much safer, have a longer lifespan, and are less toxic than normal lithium batteries, and have a very different chemistry. They don't have flamability concerns when submerged in water, they aren't poisonous.

Several manufacturers are now making them for moto/off road applications. Maybe a bit undersized for a daily driver 911, but perfect for a track day or occasional use car that is rarely if ever going to see below freezing temps.

An inexpensive and awesome way to shave almost 40 pounds!

Ballistic 16-cell battery. 500CCA, 3.6 pounds, $300 list price.


Antigravity 20-Cell battery, 600CCA, 4.3 pounds, $370.


Edited by pfbz
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I've never seen the Ballistic but interseting, I will have to look into them. As far as the LiFePO4, they are the way to go as you stated because of the lower chance of them going into melt down. The batteries you listed use the same cells as the one from Lithiummoto. The cells are made by A123 System. So they all should work the same. It's just a matter of finding the right one to suit your needs.


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Is A123 the same company that just filed for bankruptcy and is being bought out by a Chinese company?

If that's the case, it may be difficult to get warranty coverage if it's needed.

Regards, Maurice.

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Hi Maurice,

My last post didn't go through for some reason but yes, they may go bankrupt and sell out. If warranties are a big concern I would not recommend any battery other than a stock Porsche battery. A lot of aftermarket lithium battery companies use A123 because they are among the best cells on the market right now.

Like most things designed for race use, there are always warranty issues involved outside the companies liquidity.


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