Ben Nelson's Electro-Metro Build thread

[Tango Charlie]

You bought the Metro in March of '08. A year and three months later, now look at it. Wow! You have an accomplishment to be proud of, and have inspired more than one of us.
You deserve the Turtle of Kudos award!

[Planecrazy]

Originally Posted by bennelson

Hey Steve,

The cabling is fine inside the conduit. Insulation is unimportant. Wires and cables are fine at any temperature except hot.

I probably should have been more specific in my use of the word "insulation." I was using the word to describe the protection (or lack thereof) that the plastic conduit provides under the car against road debris and scraping against the pavement, versus the amount of protection afforded by keeping the wiring inside the car body.

Originally Posted by bennelson

Since this car originally had an exhaust pipe running right down the middle, I simply put the conduit where that was. That is HIGHER than the bottom of the car, because of the exhaust "tunnel".

I suspected that you might have done that. If you look again at the original picture it looks like the original conduit was hanging below that point, where it would have been dangerously exposed to high spots on the road or any road debris that could have contacted it and created havoc for you.

Originally Posted by bennelson

Running conduit inside the car would take up extra space, and there is not good straight line to do it. Flexible conduit is a possibility, but it is very expensive, whereas 2" pipe was about $3 for ten feet. Also, I would have to fish everything through the firewall if I ran it inside.

Conduit makes it nice and easy to have everything together, without having to go around corners and through firewalls. Clean and simple, and out of the way.

I suspected this was the reason you did it that way. I would probably do the same, except I would reconsider using a metal conduit (like large diameter plumbing pipe and/or boxing up the tunnel to provide extra protection from the "outside world."

Bear in mind that most homes use metal conduit (not thick enough for this purpose) to prevent the wires from too easily being compromised, and with very few exceptions ALL automotive wiring is done either inside the vehicle or run through areas of the frame that provide protection if the wires are outside the cabin. When talking about high voltage/amperage cables in an electric vehicle it becomes much more important to protect/insulate those cables from road hazards and dangers associated with possible crashes.

Originally Posted by bennelson

EDIT:
On Tom's EV Neon, we actually talked about flipping over the heat shield in the exhaust tunnel to act as an undercover for the conduit. If your conduit, up UNDER and IN your car is getting whacked, you have bigger problems than protecting your cabling.

PS - somebody please remind me in a few days to fix the leak in my driver side mirror! It's letting rain into the passenger compartment!

PPS - Come to think of it, I could run the audio out from the DVD player to the audio in on the stereo and play YouTube video's audio through the car stereo.

As your Electro-Metro is a work in progress it's nice to see you going back from time to time and upgrading things you've done differently in the past. You're providing great inspiration and setting an excellent example for those who plan to follow your lead.

Regards,

[electricman]

Originally Posted by bennelson

By "Premium" battery pack, are you referring to Lithium, etc.?

This whole vehicle project is one big low-budget experiment. ......

I think I am sticking with lead for the foreseeable future.

On a side note. I put my motorcycle's Optima Yellow Top AGMs in the Citicar for this weekend and WON BOTH DRAG RACES! Some variations of lead-acid are still pretty nice.

Here's the thing - What are the motor Specs and what are the Battery Specs? Example - Myelectricfly - Motor Rated 20.9 Hp at 90 V x 184 Amps; Batteries - Trojan SCA 150, group 24, 12V Flooded: Issue - Real Power Available from Lead-Acid (PbA) - Surrette.com specs pages show - a group 24 rated at 80 Ah {at the 20 Hr rate} but in the EV World - we need to know the ability to deliver at the 1 Hr rate - and that is just 29 Ah at 29 Amps!

So - now you know 2 things - 1st - it won't go far, and 2nd - it won't go fast, until you get better batteries! Period! So - Sticking with the same size PbA - you would need about 6 of them in parallel x 8 in series (at 50 lbs each that's about 2,400 lbs!) to get the volts and amp needed to properly drive the motor - AND - not seriously Damage your Batteries, but even then - you are still using the 1 hour rating of the battery - meaning - you clould at least get (in my car) about 100 - 120 Kms in that hour - if - a Big if - you could carry all that Lead!

Even if you go to large single monster 12V Batterie s- Rated at 275 Ah (At the normal 20 Hour rating) - the 1 Hour rating is just 99 Ah at 99 Amps, and these beasties weigh in at 172 lbs each! So - to get the best power from them - would still need 2 of them in parallel, or 344 lbs x 8 (for the 96V Nominal drive train) or nearly 2800 lbs!!! (Please note - My pack is just 400 lbs - so - you can imagine how much abuse that little pack is taking if I try to drive it on the highway, when it drops down to 75 Volts at about 185 Amps! Which I have - 7 - 8 times!)

That is about 13.8 - 14 kW, vs the rated 16kW - so I am using about 17-18 Hp to drive 100 kmh / 62 mph!

In any case - My Synopsis - Use Lead Acid Batteries in an EV - ONLY to prove your wiring, then put in real Bateries - that don't weigh tons, don't have such a large voltage drop under load (PbA about 25%), can handle the cold better if you live up north, and the heat better if you live down south, have a verifyable number of tested cycles at high 'C' Current Drains! (My Batteries - even New - were struggling to deliver 2C or 200 Amps!)

And - going to Spiral wound Yellow Tops - Might be better for High current - they are still Lead based and heavy - plus nearly more expensive than some good LiFePO4's wich have a much longer cycle life!

My Dime's worth - read more of my journey here!

[MetroMPG]

Originally Posted by bennelson

I got all my used gel batteries back from the battery shop.

The bad news is that most of them are in poor condition.
Two came back with a giant BAD magic markered on the top.
6 of them are really usable. That leaves 10 that ain't so good.

I sorted out the 6 best to put in the Metro.
It looks like possibly the best way to go is to keep the car at 72V right now. I am not sure how much better range I would get by adding 6 more batteries of poorer quality, especially since I don't have individual battery monitoring.

Well you know what I'm going to say, right?

Get yourself a monitoring system. Quick! Before you torture any of your good batteries. You might be torturing one of them right now and not even know it!

(Trying to put the fear of battricide in ya. Is it working?)

You don't even need the fancy 10 LED array per battery like the ForkenSwift has. You can do a much more simple 1, 2 or 3 LED setup that would be cheaper to assemble. Of course, the more LEDs the better resolution, and the more you can see what your right foot is doing to your poor batteries.

Heck, you could even get 6 dirt cheap voltmeters or gauges. But get something! And then you can be assured of keeping things above 1.75v per cell (10.5 per 12v batt)... battricide territory.

[bennelson]

My friend Tom is working on building some LED individual battery monitors right now.

As to fancy batteries, anyone who wants to contribute to a "Buy Ben some Batteries Fund" is more than welcome to!

[Planecrazy]

Originally Posted by bennelson

As to fancy batteries, anyone who wants to contribute to a "Buy Ben some Batteries Fund" is more than welcome to!

If I happen to pick just the right numbers in a major lottery you'll get the best Li-Ion pack available, on me, Ben!

Regards,

[bennelson]

I am trying to get my car cleaned up for the big MREA Energy Fair's Clean Car Show!

I wish I had more time!

Oh well, just try to make it look pretty!

Here is what I have been doing to get the dashboard together.

Here is the center console together, with the stereo installed.


Unfortunately, a sub-compact car does NOT offer plenty of extra room for ammeters, voltmeters, etc. However, I really don't need the ashtray or the cupholder. Those both get sacrificed to make space for guages!!!



The big analog ammeter and volt meter are up on a bit of an angle to see better while driving. The lower two round guages face straight out, so they are a little harder to see, but they are less important as well.

Yes, the whole thing is held together by black duct tape, but so what! It actually doesn't look that bad. I will probably still be adding some sort of LED individual battery monitor display, so that will change this all around anyways!

I also have a YouTube video uploading showing the "boot-up" sequence for the car as well.

PS: Electricman, thanks for stopping by. I happen to be one of the three subscribers to your blog!


[EDIT]
Here's a video of the instrumentation!

http://www.youtube.com/watch?v=tR_9NoN5tfs

[Planecrazy]

Looks good, Ben! I actually prefer the idea of analog guages for the power draw, versus digital. The fact that there are sweeping needles to quickly look at (instead of digital numbers) means that you can get a pretty good idea of what's going on without having to focus in on actual numbers. If you were to try to take it all in while moving, having three or more digital gauges could actually be quite dangerous, as it might divert your attention off the road for longer than would be advisable.

Obviously it would be a benefit to get the gauges higher up on the dash in order to keep looking down the road while quickly glancing at them, but as you've stated there is only so much room in a subcompact for placement of all the things you'd like to have... Keep up the good work!

Regards,

[bennelson]

Originally Posted by Planecrazy

The fact that there are sweeping needles to quickly look at.....

EXACTLY! I am a big fan of many things analog!

Also, for anyone who has concerns about about my conduit setup, I took a photo for you.




It's hard to tell exactly (because of the angle of the photo) but the battery box (flat rectangular part) is about an inch higher than the floor of the car. The end of the conduit runs into the battery box just up a bit from the bottom of it.

The conduit is higher than the original exhaust pipe, higher than the:front bumper, transmission, sway bar, motor, and floor pan, and protected from the sides by the floor plan.

Also, it is likely that the entire car underside will eventually have a full bellypan as well.

I caulked around the conduit to prevent any water from being able to get into the battery box.

[Daox]

Looks great Ben!