Trunk Battery Hump Delete...

[crestima]

Hi Members,

Any creative idea on how to eliminate the battery hump in the Emira trunk?
I would imagine that it entails potentially repositioning the battery, trimming the bracket/plate holder lower extrusion and replacement with a smaller size battery. I can't researching this myself as I haven't taken delivery of my Emira yet, but was wondering if there's a way to improve the size and accessibility of the already relatively small trunk volume by replacing that hump with a flat/flush cover instead. Any thoughts?

 

[DerTheDer]

Can you show a photo of said hump?

 

[Eagle7]

Can you show a photo of said hump?

That would take some work. Gone are the days when you just had a positive and negative cable connected to the battery posts. Now they have multi-wire electronic assemblies connected to the posts.

The battery would have to be tall enough to accommodate that wiring assembly in the front, but not very deep. Then you'd have to fabricate some kind of cover to replace the stock 'bump' cover.

 

[kitkat]

Hi Members,

Any creative idea on how to eliminate the battery hump in the Emira trunk?
I would imagine that it entails potentially repositioning the battery, trimming the bracket/plate holder lower extrusion and replacement with a smaller size battery. I can't researching this myself as I haven't taken delivery of my Emira yet, but was wondering if there's a way to improve the size and accessibility of the already relatively small trunk volume by replacing that hump with a flat/flush cover instead. Any thoughts?

A few of us were discussing using a smaller lithium battery and 3D printing a new BMS bracket to relocate it as well as printing a new battery door. I don’t have my car yet but this doesn’t seem that difficult to do especially with a smaller lithium battery.

 

[340r]

Smaller lithium makes sense. Lighter, longer life, longer disconnected storage. 340r runs with a motorcycle battery, albeit nearly zero electronics.

 

[crestima]

A few of us were discussing using a smaller lithium battery and 3D printing a new BMS bracket to relocate it as well as printing a new battery door. I don’t have my car yet but this doesn’t seem that difficult to do especially with a smaller lithium battery.

Not wanting to sound overly optimistic, if the 4 terminal connecting module attached to the front is attached and secured to the battery by that top bolt on the right hand side, then theoretically one could move that module to another hidden location i.e. to the left side behind the rear fender from where the wire loom is coming or elsewhere if there's an alternative space for it and then connect that module back to the battery's positive terminal using an wire extension. What I'm not sure is if relocating the module and trimming the bottom plate would ultimately result in the surface being flush with the trunk lining not and interfering with the OEM battery. If it does, then adapting a 3D Printed workable flush cover should be the lesser of our concerns. I realize that a smaller lithium battery could help resolve that extra space allowance issue, but some folks may not be willing to go for that significant additional cost particularly with a new OEM battery already in place. Thanks to all for your input so far and looking forward to other observations, ideas and solutions.

 

[crestima]

Not wanting to sound overly optimistic, if the 4 terminal connecting module attached to the front is attached and secured to the battery by that top bolt on the right hand side, then theoretically one could move that module to another hidden location i.e. to the left side behind the rear fender from where the wire loom is coming or elsewhere if there's an alternative space for it and then connect that module back to the battery's positive terminal using an wire extension. What I'm not sure is if relocating the module and trimming the bottom plate would ultimately result in the surface being flush with the trunk lining not and interfering with the OEM battery. If it does, then adapting a 3D Printed workable flush cover should be the lesser of our concerns. I realize that a smaller lithium battery could help resolve that extra space allowance issue, but some folks may not be willing to go for that significant additional cost particularly with a new OEM battery already in place. Thanks to all for your input so far and looking forward to other observations, ideas and solutions.

Sorry, but one more observation... I don't have my Emira yet so it's a bit difficult for me to determine just from the provided photo if that (aluminum?) battery tray with the lip and 2 screw holes actually sits flush to the trunk floor. The more I look at the foto, the more it looks to be to indeed be sitting on the base of the trunk floor. Someone with a live Emira, please confirm if it is indeed the case. If so, trimming that lip wouldn't even be necessary.

 

[kitkat]

Not wanting to sound overly optimistic, if the 4 terminal connecting module attached to the front is attached and secured to the battery by that top bolt on the right hand side, then theoretically one could move that module to another hidden location i.e. to the left side behind the rear fender from where the wire loom is coming or elsewhere if there's an alternative space for it and then connect that module back to the battery's positive terminal using an wire extension. What I'm not sure is if relocating the module and trimming the bottom plate would ultimately result in the surface being flush with the trunk lining not and interfering with the OEM battery. If it does, then adapting a 3D Printed workable flush cover should be the lesser of our concerns. I realize that a smaller lithium battery could help resolve that extra space allowance issue, but some folks may not be willing to go for that significant additional cost particularly with a new OEM battery already in place. Thanks to all for your input so far and looking forward to other observations, ideas and solutions.

It will still interfere with the OEM battery, from what I've seen in videos:

 

[Eagle7]

Here's what you've got without the battery.

 

[crestima]

Here's what you've got without the battery.

View attachment 44535

Yep, I see what you mean. That sucker sticks out a lot. The flush idea is perhaps still achievable, but maybe only with a much thinner lithium battery as originally suggested. Once we get the actual dimensions of the battery compartment, with depth measured to the sidewall of the trunk, we can then start searching for Lithium Batteries that would do the trick. Thank you.

 

[Eagle7]

Yep, I see what you mean. That sucker sticks out a lot. The flush idea is perhaps still achievable, but maybe only with a much thinner lithium battery as originally suggested. Once we get the actual dimensions of the battery compartment, with depth measured to the sidewall of the trunk, we can then start searching for Lithium Batteries that would do the trick. Thank you.

The factory battery (including the ridges on the bottom for the mount clamp) is about 11.5" wide and 7" deep. Figure at least another inch for that pack of stuff on the front that's part of the wiring. You'd probably need a battery that's no deeper than about 5.5" if you wanted a flush cover. You might be able to find one like that in a race battery, but finding one with enough aH capacity would be a trick.

 

[crestima]

The factory battery (including the ridges on the bottom for the mount clamp) is about 11.5" wide and 7" deep. Figure at least another inch for that pack of stuff on the front that's part of the wiring. You'd probably need a battery that's no deeper than about 5.5" if you wanted a flush cover. You might be able to find one like that in a race battery, but finding one with enough aH capacity would be a trick.

Yes, I understand your point and thanks for the input.
Trying to avoid the race battery route because of its limitations.
By any chance do you also have:

1) OEM Battery height?
2) Trunk battery cavity height?

What I'm trying to figure out now is if that "pack of stuff" which you estimate to be approx. 1 inch thick could (by configuring a new connection adapter), be alternatively moved to sit on top of the battery, instead of modulated to its front side, as it is currently. I guess I may be stretching my imagination in to the wishful thinking dimension, but hey, the thought crossed my mind.

Coincidentally, I just happen to discover that the Evora, the overall external dimensions of which is shorter and not as wide as the Emira's, has a flush battery cover presumably allowing for a bit more space and certainly less trunk access intrusion. This is even more intreaguing to me since, unlike the Emira, the Evora has back seats! Go figure...

 

[Eagle7]

Yes, I understand your point and thanks for the input.
Trying to avoid the race battery route because of its limitations.
By any chance do you also have:

1) OEM Battery height?
2) Trunk battery cavity height?

What I'm trying to figure out now is if that "pack of stuff" which you estimate to be approx. 1 inch thick could (by configuring a new connection adapter), be alternatively moved to sit on top of the battery, instead of modulated to its front side, as it is currently. I guess I may be stretching my imagination in to the wishful thinking dimension, but hey, the thought crossed my mind.

Coincidentally, I just happen to discover that the Evora, the overall external dimensions of which is shorter and not as wide as the Emira's, has a flush battery cover presumably allowing for a bit more space and certainly less trunk access intrusion. This is even more intreaguing to me since, unlike the Emira, the Evora has back seats! Go figure...

OEM battery is just shy of 8" tall, so figure about 10" for the height of the cavity. One of the things with a different battery is there has to be enough room between the terminal post on top, and the front edge of the battery for the L shaped terminal assembly to fit over it.

 

[crestima]

OEM battery is just shy of 8" tall, so figure about 10" for the height of the cavity. One of the things with a different battery is there has to be enough room between the terminal post on top, and the front edge of the battery for the L shaped terminal assembly to fit over it.

Got it. I guess I'll wait until I get my Emira to try to find a new battery that will work with those dimensions and will report back later on with any breakthrough. I get a feeling that I'm not going to get along too well with that hump in the trunk...Thanks again.

 

[Eagle7]

I just went out and measured. The 'hump' sticks out about 3". From the back of the enclosure to the front of the cable terminal pack on the front of the battery, it's 9 1/4". I have the Antigravity battery installed, but I believe it's the same depth. It looks like there's about an inch of space between the back of the battery and the back wall of the enclosure.

If you designed a new aluminum mounting plate to replace the factory one bolted to the bottom of the enclosure, you might be able to use another half inch of space behind the battery, but even then you'd need a battery with a depth of around 5 1/2 inches if you want a flush cover in the trunk. If you're willing to give up a half to an inch of space with a new cover, you may have more choices in a battery. You could also try measuring exactly what you'd need to get a flush cover, and send those dimensions to a battery company to see if they could make one to your specs. Then of course you'd need to design and probably 3D print a new cover.

It's doable, but lIke most things, just takes time and money.

 

[crestima]

I just went out and measured. The 'hump' sticks out about 3". From the back of the enclosure to the front of the cable terminal pack on the front of the battery, it's 9 1/4". I have the Antigravity battery installed, but I believe it's the same depth. It looks like there's about an inch of space between the back of the battery and the back wall of the enclosure.

If you designed a new aluminum mounting plate to replace the factory one bolted to the bottom of the enclosure, you might be able to use another half inch of space behind the battery, but even then you'd need a battery with a depth of around 5 1/2 inches if you want a flush cover in the trunk. If you're willing to give up a half to an inch of space with a new cover, you may have more choices in a battery. You could also try measuring exactly what you'd need to get a flush cover, and send those dimensions to a battery company to see if they could make one to your specs. Then of course you'd need to design and probably 3D print a new cover.

It's doable, but lIke most things, just takes time and money.

Humm.. I'm going to try to contact someone at GRP to see if they would be interested in moving forward with this idea. I figure that since they already offer antigravity batteries as such, they could develop their own adaptation for base plate and flush access cover to be sold along with a suitable battery as a kit, offering the potential dual benefit of battery weight reduction and trunk hump delete. I, for one, wouldn't even think twice about dashing out extra $ to buy such a kit. Nothing to lose for asking.

 

[Eagle7]

Humm.. I'm going to try to contact someone at GRP to see if they would be interested in moving forward with this idea. I figure that since they already offer antigravity batteries as such, they could develop their own adaptation for base plate and flush access cover to be sold along with a suitable battery as a kit, offering the potential dual benefit of battery weight reduction and trunk hump delete. I, for one, wouldn't even think twice about dashing out extra $ to buy such a kit. Nothing to lose for asking.

That would be a very interesting upgrade. Opening up the extra 3 inches of space on that side of the trunk would be useful.

 

[PsymonR]

I don't think it will be possible to have zero hump intruding into the boot of the car due to how the cables that connect to the battery enter the space. If you could get a suitable battery you may be able to get a setup that is mostly flush but with a small intrusion towards the side of the car to give space for the cables to get into the battery cavity.

 

[Eagle7]

I don't think it will be possible to have zero hump intruding into the boot of the car due to how the cables that connect to the battery enter the space. If you could get a suitable battery you may be able to get a setup that is mostly flush but with a small intrusion towards the side of the car to give space for the cables to get into the battery cavity.

View attachment 44742
View attachment 44743

If you've moved the terminal assembly back, then you'd just need a small bump at the lower end to accommodate where the cables are coming in. That would still free up all the space above it which might help in fitting some things into the trunk.

 

[crestima]

I don't think it will be possible to have zero hump intruding into the boot of the car due to how the cables that connect to the battery enter the space. If you could get a suitable battery you may be able to get a setup that is mostly flush but with a small intrusion towards the side of the car to give space for the cables to get into the battery cavity.

View attachment 44742
View attachment 44743

Yes, I believe you're correct in that the bulge to the left of the trunk would have to remain to accommodate that wiring. The aim to eliminate the longitudinal extrusion, finished with a more flush cover, would hopefully result in 2.5 to 3 inches of additional usable left side trunk space as well as improve the accessibility of placing and removing items in that specific area. I already sent a message to GRP, via their website, to see if they could look in to this idea to help develop a kit, if at all feasible. Since such a solution will most likely imply the need for a different type of battery, a bracket/plate adaptation and a new flush cover, the experience and resources of an existing auto accessory provider (such as GRP) would be ideal.
Just to be clear, my angle on this is purely as a consumer seeking to improve on a car that I really enjoy, so I have absolutely no interest in exploiting this from a commercial perspective. This being the case, any member herein who agrees with the benefits of the trunk bulge delete solution, should feel free to pass on this idea to any other potential developer/seller. Many thanks