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Old 02-16-2016, 12:31 PM   #87 (permalink)
Stubby79
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Question

Pondering my battery boxes...cuz, hey, it'll take me a while to decide what direction to go...might as well start thinking well in advance!

I'd like 2 modules of 24 cells each, in a uniform layout. I can either do 4x6 or 3x8 cells to get this. Or any other combination, really, but these give me a nice size & shape for handling, as well as being at my comfortable limit for lifting by hand, if necessary.

I'd like clear access to the motor's electrical connections, if possible. (But I intentionally rotated my motor to face forwards, so I can get at them from underneath, even if there's a box right over top of the motor). And, for potential "expansion reasons", it would be nice if the area immediately in front of the motor was clear.

It would be great if I could keep the weight low and behind the center line of the front wheels...but that's dreaming! I'd have to be doing a mid-engine car to pull that off. Hmm...naw, don't need to follow that thought. So, unless I want to put the batteries in the back, or at least half of them, I'm stuck putting them under the hood. That has some advantages, at least...

Also not likely to be able to mount them low, again for balance/handling...not without making access to them almost impossible. No easy access to them sounds risky to me...so easy access is required.

I can always move them later, once I'm confident of their well being and if I feel the need to re-arrange the weight distribution.

So, not quite trusting my ability to measure and envision things in place, I mocked up some boxes to get a feel for how they will fit.


This first layout is about the only one that permits me to keep the two packs flat and uniform. One is 6x4 the other is 8x3. They're not twins, but there isn't really enough room for two matching, without cutting the car's sheet metal to make room. It's fairly aesthetically pleasing, since the front of both boxes line up:



It leaves me with access to things on the firewall...



And, with the pack on the left sitting low and level, there's room on top for, say, my motor controller:



While the pack on the right is forced to sit at an angle to match the hood and the transmission.


This shot is just checking to see if the two packs could be lengthwise beside each other...

...a little too tight.

The 6x4 is a great fit over the motor...

....but the other module would have to be "stepped" to fit. Or located elsewhere in the car.

Would two 6x4s fit?

No, that's past the half-way point.

8x3 fits between the booster and the strut tower...

...but has to be raised to get over the trans, so no space for controller...nor anywhere to fit the other module intact.

And interfere with the hood:

(imagine my tape measure is the hood)

So, back to the original. Titled up on the left side to match the right?

While visually appealing, I lose controller space.

And, out of curiosity, can I fit the 6x4 up against the firewall, on end?

Yes, apparently I can...whatever that's worth.


So, most likely I'll go with the original layout. It leave me easy access to everything. I do have to give up some of the space and the visual access to the motor's terminals, and the weight will be sitting up high...though probably no worse than an engine would.

Meh.

Thoughts?
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