OK, the battery in my car is the smaller of the two batteries that may come with our cars. Depending on equipment it seems the batteries weigh between <b>49 LBS and 59 Lbs</b>. As you will see, I decided on the Odyssey PC680T for my use. The main reason behind the purchase of this model was that it came with optional automotive terminal posts. I did not want to fiddle with the connections if I could avoid it.

The battery weighed in at <b>14.5 Lbs</b> with the brass automotive terminals. My OEM battery as I said before weighed in at <b>49 Lbs</b>. A net savings of <b>34.5 Lbs</b>. However, I did not want the new and smaller battery to be "just installed" in the bigger OEM's battery location without it being well secured.

So this where I got **** about the whole thing. I decided to design and fabricate a safe mounting system for the Odyssey; something I felt would be able to resist breakage in case of a hard impact (accident). In the end I regained <b>1.59 Lbs</b> because of my mounting system so now my new final weight savings is only <b>32.91 Lbs</b>! So here we go with the pictogram...



Side by side the OEM battery and the PC680T.

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Side by side, another angle.

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Now let us take a look at how the OEM battery is supported and secured in place.

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The rear part of the battery slides into a recessed part of the plastic shelf. I put a carpenter's pencil in the location where the edges of the battery fit in.

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Here you can see the bevelled edges of the OEM battery (sorry for the out of focus pic).

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In the front the battery is secured by the same bevelled edges but a plastic retaining clip with a screw is tighten to keep the battery in place (again sorry for this second out of focus pic).

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Since the PC680T is much smaller I decided on using an aluminium plate to make a base as to sit the smaller battery on it. It is 9 inches wide by 6 inches deep and is 3/16TH thick.

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To duplicate the way the rear part of the OEM battery uses its bevelled edges to fit into the rear shelf, I decide to weld two "blocks" of aluminium onto the base and grind them until they fit into the same slot as the OEM battery. They also had to be bevelled.

<a href="http://photobucket.com" target="_blank"><img src="http://i17.photobucket.com/albums/b79/mlab601/RearShelfFitting.jpg" border="0" alt="Image hosting by Photobucket"></a>

This picture from another angle shows both the rear bevelled blocks and the front one.

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The next step in the design was to have a way to secure the battery itself from moving on the base from side to side of back and forth. So six right angled aluminium pieces were welded in place.

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I decide to add a small rubber pad in the "cradle" to soften the pounding the battery might encounter.

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Now to test fit the battery in its new cradle.

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Of course I wanted to secure the whole assembly even further. So far we have taken care of the base being secure (with the bevelled blocks), the battery can't go back and forth or from side to side (because it sits in a cradle) but it could go up and down! So I designed this "security strap" that fits around the back side around the top and back down the front side. All this secured to the base by bolts.

<a href="http://photobucket.com" target="_blank"><img src="http://i17.photobucket.com/albums/b79/mlab601/Aluminumbatterysecuringstrap.jpg" border="0" alt="Image hosting by Photobucket"></a>

To secure the security strap to the base I used some Heli Coil inserts. I did not want to have nuts underneath the base that could damage the metallic part of the chassis or the plastic shelf.

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Two 6mm hex bolts with two regular washers and two lock washers were used to secure the security strap to the base.

<a href="http://photobucket.com" target="_blank"><img src="http://i17.photobucket.com/albums/b79/mlab601/SecuringHardware.jpg" border="0" alt="Image hosting by Photobucket"></a>

Here is what it looks like with the security strap installed.

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Prior to the installation of the new assembly in the car, I cleaned the front portion of where it was going to rest on, the chassis near the fire wall. I then laid some aluminium tape to prevent the chemical reaction between aluminium and steel.

<a href="http://photobucket.com" target="_blank"><img src="http://i17.photobucket.com/albums/b79/mlab601/FrontRetainingShelfandAluminumTape0.jpg" border="0" alt="Image hosting by Photobucket"></a>

I then went ahead and painted the aluminium tape red.

<a href="http://photobucket.com" target="_blank"><img src="http://i17.photobucket.com/albums/b79/mlab601/FrontRetainingshelfandPaintedAlumin.jpg" border="0" alt="Image hosting by Photobucket"></a>

Of course the job would not be complete without painting the new assembly.

<a href="http://photobucket.com" target="_blank"><img src="http://i17.photobucket.com/albums/b79/mlab601/Aluminumbasepainted.jpg" border="0" alt="Image hosting by Photobucket"></a>

Here are a few other pictures of the completely terminated project installed in the car.

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Installation picture 2.

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Installation picture 3.

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Well done bud! Excellent write-up.

 

Thanks Sia. Wait until you see the next project, it should be an interesting one.

 

if you are hit hard enought to dislodge the battery that is the least of your worries. astreet colision is likely 2 g's - so thats like 30 lbs force on the hardware, 15 lbs force per screw if you only had the strap with two screws.

 

I'm sure it works if you say it does, but will it last and will it start in the cold?

Reserve Capacity aside, "Cold Cranking Amps" (CCA) is the most stringent measurement for a car battery and it's defined as the number of amps a fully charged battery can deliver at 0 Fahrenheit for 30 seconds, while maintaining a voltage of at least 7.2 volts.

Even the less stringent "Cranking Amps" (CA) is defined as the discharge load which a fully charged battery at 32F, can continuously deliver for 30 seconds and maintain a terminal voltage equal or greater than 1.2 volts per cell.

So, although they'd like you to believe that the "Cranking Amps" of this battery is 680, that rating is only tested to 5 seconds according to the link below... Odyssey doesn't publish true Cranking Amps (30 seconds @ 32F) nor CCA (30 sec@0F) for this battery.

Then again it might be a moot point. Does anyone actually know what B6/B7 S4 OEM batteries put out? We can probably perform a rough extrapolation to find the true CCA of the Odyssey battery given the data we have on it and do more of an apples to apples comparison.<ul><li><a href="http://www.odysseybatteries.com/battery/pc680t.htm">http://www.odysseybatteries.com/battery/pc680t.htm</a</li></ul>

 

I can back that up with math if necessary. ;-)

 

Nice job.

 

not enough for the dead of winter, imo, but should do fine in warmer months

this is what its rated for, if your math shows differently, its possible that "rated" is a conservative "min"<ul><li><a href="http://www.eastcoastbatteries.com/page3.html">http://www.eastcoastbatteries.com/page3.html</a</li></ul>

 

Impressive work! Mods get this posted in the tech section....

 

The current ratings are on the battery in the pictures