What does the stock battery in a GT350 weigh?

Wooly · Jun 21, 2018

I’m looking into the possibility of a lightweight battery for my 2017 GT350R and was wondering if anyone knows what the stock battery weighs and if anybody has done this? If so what battery and mount did you choose and why?

JohnD · Jun 21, 2018

Not sure about GT350, but my GT battery weighs 33 lbs. Braille B2015 weighs 15 lbs. The bottom of the stock GT battery tray has a depression in it and the Braille will sit right in that depression if you use a dremel and open up the top outer edges of it by about 1/8". The cables fit on and it doesn't move. There are a variety of ways to fix it in place more securely if you feel the need. These cars have a crapload of parasitic load and while that battery spins the motor without a problem, it's probably best to keep a maintainer on it. Or put a ground disconnect on it. Or take it out and put the stocker in for DD use. Takes all of 10 minutes to swap them.

cjgt350 · Jun 22, 2018

https://www.mustang6g.com/forums/showthread.php?t=74433&page=18

Post #267 (important - read the red print)

JohnD · Jun 22, 2018

cjgt350 said:
https://www.mustang6g.com/forums/showthread.php?t=74433&page=18

Post #267 (important - read the red print)

Right. And that's why I went with that specific Braille, it's an AGM battery and fully compatible with ordinary charging systems, whereas Lithium batteries are a different animal with respect to charging profiles. Maybe in a few years they'll get the bugs out of lithium but for now they're far more expensive and far more prone to charging failure.

I've been monitoring the voltage on this car with both batteries, I don't know what they're doing but the voltage is always far below what I would expect it to be at, especially so with the Braille. There certainly is a lot of draw on the battery, I've seen the Braille regularly at 12.2 volts and never over 12.8, the stock one floats between 12.5 and 13 volts.

I really do like the idea of a 5 pound battery vs a 15 pound one though, and lithium is the only way to get there that I am aware of.

Good picture in that post, you can see the little depression in the bottom of the battery tray that the Braille sits right into once opened up a tiny bit.

cjgt350 · Jun 22, 2018

Zero issues with the lithium battery model I am running now. Three track days and kept on a lithium specific battery maintainer if the car sits for more than a few days.

Mach4.6 · Jun 22, 2018

I ran a Braille, lasted about 6 months, it's not any fun sitting in grid and wondering if your car is going to start?
Here's my post about the battery I run now, yes it's expensive but you get what you pay for.
See post #49
https://www.mustang6g.com/forums/showthread.php?p=2259188#post2259188

https://p10.secure.hostingprod.com/...g/product_info.php?cPath=1_32&products_id=125

Wooly · Jun 22, 2018

Mach4.6 said:
I ran a Braille, lasted about 6 months, it's not any fun sitting in grid and wondering if your car is going to start?
Here's my post about the battery I run now, yes it's expensive but you get what you pay for.
See post #49
https://www.mustang6g.com/forums/showthread.php?p=2259188#post2259188

https://p10.secure.hostingprod.com/...g/product_info.php?cPath=1_32&products_id=125

Yes, I currently run the Voltphreaks battery in my Porsche. I have had no problems with it and love it, unfortunately the cost is prohibitive. I was looking for a lower cost solution.

jedirocker · Jun 22, 2018

Mach4.6 said:
I ran a Braille, lasted about 6 months, it's not any fun sitting in grid and wondering if your car is going to start?

Which Braille model were you running?

Demonic · Jun 22, 2018

JohnD said:
Right. And that's why I went with that specific Braille, it's an AGM battery and fully compatible with ordinary charging systems, whereas Lithium batteries are a different animal with respect to charging profiles. Maybe in a few years they'll get the bugs out of lithium but for now they're far more expensive and far more prone to charging failure.

I've been monitoring the voltage on this car with both batteries, I don't know what they're doing but the voltage is always far below what I would expect it to be at, especially so with the Braille. There certainly is a lot of draw on the battery, I've seen the Braille regularly at 12.2 volts and never over 12.8, the stock one floats between 12.5 and 13 volts.

I really do like the idea of a 5 pound battery vs a 15 pound one though, and lithium is the only way to get there that I am aware of.

Good picture in that post, you can see the little depression in the bottom of the battery tray that the Braille sits right into once opened up a tiny bit.

The issue isn't as much as the lithium batteries having bugs, but more an issue with the 2015+ Mustangs having a relatively advanced charging system that doesn't always work well when some lithium battery manufacturers build protection circuits into the batteries. The lithium voltage window is smaller than for lead acid and AGM batteries, so on a car with smart charging, like ours, which intentionally varies the voltage output of the alternator, it can sometimes trigger the high or low voltage protections in the batteries.

The reason the charge voltage on your two batteries is different is very likely because you didn't do a battery management system reset when you put the new battery in. The car uses multiple sensors to try to determine the characteristics of the battery and then stores them. If you change to a different battery the car thinks the old battery it saw before is still present, which can affect the way it charges the new battery. The BMS reset can be done with Forscan or by a dealer who knows what they're doing.

Right now I'm running the Antigravity ATX20 non-restart as part of some testing for Antigravity, and following the BMS reset I've been monitoring the sensor outputs through Forscan and have had absolutely no issues. I'm currently talking to them about trying to produce a version of their Restart batteries specific for the Mustang charging systems though since their Restart protections are currently too conservative for the Mustang charging system.

Other uses have had good success with the Volt Phreaks batteries, which do have internal protections, but they don't cut in as easily and so far seem to be fine for the Mustang systems.

Whichever way you go though, make sure to reset the car's BMS if you put a new battery in.

Mach4.6 · Jun 22, 2018

jedirocker said:
Which Braille model were you running?

B129

jedirocker · Jun 22, 2018

Mach4.6 said:
B129

Thanks. I'm considering the B3121 (21 lbs) as it seems to be better suited for casual driving of a V8.

JohnD · Jun 22, 2018

jedirocker said:
Thanks. I'm considering the B3121 (21 lbs) as it seems to be better suited for casual driving of a V8.

The B2015 has plenty of power for the Coyote, spins the engine over hot or cold just as well as the stock battery does. Plus a nice loss of weight.

Those VoltPhreaks batteries are a thousand bucks according to their website. A tad over the top for just dinking around with a car on a track for shits and giggles.

Stroked89coupe · Oct 2, 2018

Demonic said:
The issue isn't as much as the lithium batteries having bugs, but more an issue with the 2015+ Mustangs having a relatively advanced charging system that doesn't always work well when some lithium battery manufacturers build protection circuits into the batteries. The lithium voltage window is smaller than for lead acid and AGM batteries, so on a car with smart charging, like ours, which intentionally varies the voltage output of the alternator, it can sometimes trigger the high or low voltage protections in the batteries.

The reason the charge voltage on your two batteries is different is very likely because you didn't do a battery management system reset when you put the new battery in. The car uses multiple sensors to try to determine the characteristics of the battery and then stores them. If you change to a different battery the car thinks the old battery it saw before is still present, which can affect the way it charges the new battery. The BMS reset can be done with Forscan or by a dealer who knows what they're doing.

Right now I'm running the Antigravity ATX20 non-restart as part of some testing for Antigravity, and following the BMS reset I've been monitoring the sensor outputs through Forscan and have had absolutely no issues. I'm currently talking to them about trying to produce a version of their Restart batteries specific for the Mustang charging systems though since their Restart protections are currently too conservative for the Mustang charging system.

Other uses have had good success with the Volt Phreaks batteries, which do have internal protections, but they don't cut in as easily and so far seem to be fine for the Mustang systems.

Whichever way you go though, make sure to reset the car's BMS if you put a new battery in.

How did testing go for you with this model?

Demonic · Oct 8, 2018

Stroked89coupe said:
How did testing go for you with this model?

I've been using the non-Restart ATX20 (model number on the site I believe is YTX20) for a couple months now in my street driven car (at least until track season in New England starts this coming Spring). I haven't had any issues, and have been completely happy with. I stopped hooking it up to a tender since I can easily let the car sit for 2 weeks and it starts right up. The ATX30 (which has Restart) in its current form isn't compatible with the Mustang charging systems. This month I should be receiving a revised version from the owner to try in the car and run through Forscan to see how it responds with the charging systems.

What does the stock battery in a GT350 weigh?

Wooly

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JohnD

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cjgt350

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JohnD

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cjgt350

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Mach4.6

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Wooly

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jedirocker

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Demonic

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Mach4.6

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jedirocker

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JohnD

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Demonic

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