Battery Placement.

[doddmoore]

When I was out in CA I met with slpro1207 (Scott) who had moved his battery to the engine compartment with the Breeze mount I believe. How many of you have moved the battery to the front and why? I am at the sheet metal phase and need to decide before I get my engine in. Mine will be a street car, not a show or track car. Also I am doing the drop trunk mod if that matters. Thanks for the input in advance.

[SteveHsr]

Battery in front results in easy access, short neat wiring, and weight low and on right side of car. There is no advantage to locating above the c.g.in the rear of the car (plenty of rear weight bias without it) that I can see. Some put it there so it is not seen in engine compartment. Seems that a finished cover could fix that.

[edwardb]

I'm a fan of the front mounted battery. The Breeze kit works great. As already stated, results in short and direct battery cable runs. Mainly though gets it out of the stock trunk location, which hogs valuable trunk space. Rear under trunk boxes are available which are fine, just haven't gone that way. Only work with solid axle though. Not an option that I know of for IRS.

[Jeff Kleiner]

I've done cars with both front and rear. Unless there are space limitations my preference is front for the reasons mentioned in the previous replies.

Jeff

[Jim1855]

Just to offer something different.

My plan is to put a Braille B3121 on the passenger side, below the upper trunk floor and above & behind the IRS. Haven't done it yet but testing with a cardboard box model it fits.

Jim

[Mark Reynolds]

Breeze 70561 Engine Compartment Battery Mounting Kit
for FFR Mk3, 3.1 and 4 Roadster

This kit allows you to mount a group size 51 battery in the engine compartment of Mk3 and newer FFR Roadsters. The group size 51 battery was chosen because of its shape and weight. Its narrow shape facilitates installation low between the front X-member and the front transverse 4” round tube. It saves 11.5 lbs compared to the 40 lb Group 34 Mustang battery it replaces.

Benefits of this kit are:
- Improves handling performance because it lowers the center of gravity of the car by placing the battery only 3/4” above the bottom of the 4” tubes, and because it reduces polar moment of inertia (resistance to turning) since the battery is closer to the center of the car (location is between the axles).
- Saves 11.5 lbs weight by replacing the 40lb Group 34 Mustang battery.
- Lowers cost and reduces build time by eliminating the need for remote battery terminals and a battery cut-off switch (easy under-hood battery access).
- Eliminates the need to replace the FFR supplied 4 gauge positive cable with a heavier 2 gauge positive cable due to shorter positive battery cable.
- Frees up valuable trunk space
The tray and all mounting hardware are stainless steel. No additional finishing needed – This kit comes ready to install including all the needed negative and ground cables! Batteries not included.

Think you won't like the looks? Well, most engine compartments have battery's in them and this is so low that most people don't even notice it.

[Mark Reynolds]

Breeze 70561 Engine Compartment Battery Mounting Kit
for FFR Mk3, 3.1 and 4 Roadster

This kit allows you to mount a group size 51 battery in the engine compartment of Mk3 and newer FFR Roadsters. The group size 51 battery was chosen because of its shape and weight. Its narrow shape facilitates installation low between the front X-member and the front transverse 4” round tube. It saves 11.5 lbs compared to the 40 lb Group 34 Mustang battery it replaces.

Benefits of this kit are:
- Improves handling performance because it lowers the center of gravity of the car by placing the battery only 3/4” above the bottom of the 4” tubes, and because it reduces polar moment of inertia (resistance to turning) since the battery is closer to the center of the car (location is between the axles).
- Saves 11.5 lbs weight by replacing the 40lb Group 34 Mustang battery.
- Lowers cost and reduces build time by eliminating the need for remote battery terminals and a battery cut-off switch (easy under-hood battery access).
- Eliminates the need to replace the FFR supplied 4 gauge positive cable with a heavier 2 gauge positive cable due to shorter positive battery cable.
- Frees up valuable trunk space
The tray and all mounting hardware are stainless steel. No additional finishing needed – This kit comes ready to install including all the needed negative and ground cables! Batteries not included.

Think you won't like the looks? Well, most engine compartments have a battery in them and this one is so low that most people don't even notice it.

[doddmoore]

Mark I’ve got so many things in my wishlist this is just one more to add. You guys do a great job. Adding the battery kit to the wishlist as well.

[RBachman]

Mark I’ve got so many things in my wishlist this is just one more to add. You guys do a great job. Adding the battery kit to the wishlist as well.

Dittos!

[Hotyacht]

I'm a fan of the front mounted battery. The Breeze kit works great. As already stated, results in short and direct battery cable runs. Mainly though gets it out of the stock trunk location, which hogs valuable trunk space. Rear under trunk boxes are available which are fine, just haven't gone that way. Only work with solid axle though. Not an option that I know of for IRS.

I have mounted my battery under the trunk with the old T-Bird IRS with no problem - don't know about the newer Mustang IRS though?
113056

[Avalanche325]

I am a fan of in the back under the trunk floor. Out of site and where these cars need the weight. The only time in the last 5 years / 21k+ miles I have needed to get to the battery was........never.
Yes, it is technically better to have a shorter positive cable. But not an issue with proper cable size. The negative is short no matter where you put it.
Batteries don't like heat or cold. But even up front I don't think it is significant.
If it was a choice of IN the trunk or up front. I would go up front. But under the trunk is my choice.

[miller7448]

Under trunk floor works with IRS as long as you use (2) six volt cells.

[mlewis]

Under trunk floor works with IRS as long as you use (2) six volt cells.


that's what I'm doing as a full size battery will not fit with the post '17 IRS

113117

[edwardb]

I have mounted my battery under the trunk with the old T-Bird IRS with no problem - don't know about the newer Mustang IRS though?
113056

That's what I was referring to. The newer 2015+ Mustang based IRS in a Mk4. From the FFMetal website: "NOTE: For MK4 chassis with 2015 IRS. If your kit was produced before July 2017, please contact me before ordering. FFR changed their chassis design for 2015 IRS setups, and you may not have room for this battery box. For kits purchased after July 2017, sorry we're both out of luck."

I read some months ago he was looking at using two smaller batteries versus one large one. Looks like that didn't happen.

[DavidW]

I have the battery in the trunk, it takes up valuable space as mentioned. It would be nice to be able to fit a chair in the trunk for those car shows. I wouldn't change it though because I like the look of the engine bay without the battery. If you go with the trunk battery pay attention to your starter requirements for battery wire gauge. I was using the 4 gauge wire supplied by FFR then switched over to the size specified by my starter 00 gauge. It made a huge difference, went from turning over 4-5 times before starting to 1st time every time.
https://thefactoryfiveforum.com/attachment.php?attachmentid=113123&d=1567077970

[shackf16]

I'm a big fan of the under trunk floor design for lots of reasons, but mainly weight distribution, more trunk space (especially with dropped trunk floor mod) and it freed up space in the engine bay to mount my ABS pump without being too crowded. I haven't finished my trunk interior but do have the aluminum cover plate over the trunk and it looks great. Pretty sure I got it from FFMetal over 10 yrs ago.

[emac]

2012 build and I went with under the trunk mounting. FFmetal box. I ran a wire to the rear of the trunk to hook up a battery tender. In 7 years I have never opened to battery lid to check on it! Battery might stay cooler in trunk than engine compartment. The main cable runs up to a cutoff mounted under the dash, so a terminal is on the firewall to add stuff or if you need to jump it off