# Battery Box Mounting



## DavidDymaxion (Dec 1, 2008)

Don't forget that the motor is not dead weight, it is twisting with enough force to drive the car. In addition to the motor's weight, it is generating 100's of foot pounds of torque. To make it worse, the tranny multiplies torque. To make it even worse, electric motors often make more torque than the gas motor they replace.

Another reason to use the original motor mounts is the rubber isolation. If your motor or tranny vibrates enough, solid metal-to-metal could turn your car into a drum.

Finally, you want about the same compliance in the mount as the stock car. If the rear of the tranny is rubber mounted, but you mount the front metal-to-metal, the motor+tranny combo will bounce up and down a little and tend to fatigue a metal-to-metal mount.

Nissan spent alot of money engineering the motor mounts -- take advantage of it!


300zxev said:


> Hi All
> 
> Just trying to get my head around the best option for mounting the front battery racks.
> 
> ...


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## ZeroGasoline (Jul 30, 2008)

I agree with DavidDymaxion.

I used the existing motor mount in my Tercel and mounted both ends of the bracket in rubber bushings. Even with a smaller motor like mine, it's going to twist and pull a little bit. 

Also, the motor is much more expensive than a couple of batteries, so I would never shift stability away from the motor to the batteries (when mounting). I'd much rather see a couple of batteries fall than my motor (and I did drop that and my transmission due to an improper motor mount - not a good feeling!).

It's a bit like a game of Tetris trying to fit everything in the motor compartment. I managed to fit 4 batteries where the radiator used to be. When I redo the car this summer I'm going to try and fit two more in the engine compartment by re-arranging some things. It might just be possible.

Best of luck to you!


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## aeroscott (Jan 5, 2008)

300z turbos have bullet prof differential and other upgrade parts . should make a great ev ether way .


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## atzi (Jun 26, 2008)

300zxev said:


> Hi All
> 
> Just trying to get my head around the best option for mounting the front battery racks.
> 
> ...


Your battery pack is only 250kg or 550lbs? That is a very small pack. How many miles are you planning on a charge?

Most EVers do not install the batteries in rubber vibration absorbing mounts of any kind. Mount to Shell(body) or chassis(frame) either I believe will be fine.


300zxev said:


> I can post some pics of the empty engine bay if anyone would like to offer suggestions ... ...


Yea lets see what you got and give dimensions. Give dimensions of batteries you are using.


300zxev said:


> Or if anyone has pics of battery rack mounting, that would be great also.





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## 300zxev (Dec 5, 2008)

Hi 

The total battery array will be more like 400-440kg ...
I am hoping to fit 250kg under the bonnet with the rest recessed into the hatch at the rear.

Thanks to the feedback ... I think I will use the existing engine mounts to attach the motor ... 

There are ledges in the engine bay which I could reverse an angle iron on to hold a battery rack. On the ledge currently there are a few PS lines on one side which can be moved around and on the other side I still have the AC hoses, which I'm starting to think I might do without anyhow.


There is also a cross member down below, should I use this for the battery rack also or is it not structural enough.

I've attached a couple of pics of the engine bay and one of the battery blocks I'm making ... It's probably a bit hard to make out though


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