allegretto

a lightweight battery?

the stock one rides amazingly high in the chassis

2slow2speed

If you are not thinking about relocating the battery the easiest mod would be a Odyssey PC925 battery with a Rennline battery mount ~26lbs total weight. Weight savings vs stock 22~23lbs. About a $320.00 mod. $135. for the mount $170 for the battery.

A more substantial weight reduction of 32lbs would be possible going with a PC680 battery and Rennline battery mount ~16lbs total weight, just be aware that the side engine bay cooling fan can drain the battery if the car is driven hard and the car is turned off and the fan remains on for a while.

The only additional hassle is the need for a battery tender if the car is not driven frequently (must for the PC680 a maybe for the PC925)

Marine Blue

This is something I definitely plan on doing once my stock battery dies. Hopefully by that time we will have even better options with more juice and less weight.

allegretto

925 seems to be the Odyssey number

does anyone know number that describes the battery footprint? 35, 48, 49???

I'm thinking on like this of the right size...

http://www.braillebattery.com/index.php/batteries/480r/

looks like plenty of cranking amps and I have all manner of battery tenders

weight loss is the BEST way to improve a vehicle's handling. Nothing else is nearly as effective. HP cannot make it up.

I think the factory model is still ridiculously expensive, anyone seen deals?

stevecolletti

Do you mean the factory Li-Ion? If so, the option comes with a standard battery as well as the Li-Ion one. Some people on the GT2/GT3 forum have bought the option and resold the Li-Ion battery, but I wouldn't call it a deal, even then.

I've used the Odyssey batteries in 680, 925 and 1200 sizes. The 680 is fine for a daily driver, race car or one carefully(!) watched - assuming limited electrical load and no electrical problems. The 925 and 1200 work fine in cars that are DD, have a kill switch or are put on a tender. Their deep cycling is amazing in that they seem to be able to come back from anything. They are reasonably priced and the only downside I've found is that when they die... they die, no real warning whatsoever. The 925 and 1200 fit in the old (1960s/1970s), standard battery box, taking up between 60 and 70% of the available space, and I've been able to use the factory hold-downs.

I have no personal experience with braille batteries, but have a friend with an Elise that swears by it.

Personally, when my battery dies, I'll be looking at the VoltPhreaks. They are pricey (~$1200), though not as pricey as the OEM Li-Ion, but they also include a circuit that disables the battery when the voltage gets too low. You then hit a button to open the circuit and can start the car. The 5.5lb one is supposed to work on Gt3s. There's a thread or two in the GT2/GT3 forum pages.

allegretto

thanks, I'll look into voltphreaks. the factory unit also has a built in kill but I think they want about $3K for it. I'm checking...

Byprodriver

Anyone looked into mounting battery on the floor by the spare tire to really "lower" the weight?

allegretto

well, I have thought about it, but I'd have to mount it by making holes in something, and I'd still have to be sure it vented. And then how to shield it, cover and all

I asked the GM at my store to see what he could steal for me, he's usually creative... we'll see

the Braille is even less wt., 10 lbs and seems to be a very powerful battery. Doesn't say if it has a low voltage cut out or if I'll have to install one. Either way, I have tenders...

hey Steve, just looked at the Voltphreaks VPH 750 looks sweet, thanks

adding lightness is always the most costly, but also almost always the most effective way to help a car perform

stevecolletti

And you don't worry as much about 5.5 pounds being mounted high.

allegretto

GM could get me a rebuilt Porsche battery for $2200, new $4500. I told him they must be very proud of their batteries.

Talked with Braille and Voltphreaks on the phone and went with the Voltphreaks VPH 900. Very powerful and weighs about 7.5 lbs. I'll let you guys know how it goes...

Marine Blue

Take some pictures of the install, I know many here would be interested in seeing this.

mrzoop

from over on the 997 side...

https://rennlist.com/forums/997-foru...0-a-pound.html

allegretto

Odyessy 925 weighs much more than this one, but weight reduction is weight reduction

allegretto

OK, so I wait 2 weeks and still no Voltphreaks battery. Call them and they say they will try to get it into production next week! Never notified me. This is the sign of a company out of control... I get a refund

Call Braille and after discussion we decide on this one. 9.8 lbs and more power than a stock battery

Was going to take pics of the install, but it's just so easy. Same length and width as stock, just 2 in shorter. Used the stock battery clamp, although it doesn't really have a shelf to "catch" on like the stock battery does at the bottom. Nonetheless it pinches enough to keep it from going anywhere.

So, just dropped ~ 30lbs more from above the roll axis.

One more point; connected a battery tender to the leads before disconnecting the old battery. So voila, no radio outage. It did throw a code that PSM and rotating headlamps were in need of reset. But drove it, shut it down and started it up again and all was forgiven. very clean and easy...

Z356

allegretto: Did you weight your old Porsche battery to confirm it was 40 lbs? How much did the 9.8 lbs Braille actually cost? Saludos, z356.