Ben Nelson's Electro-Metro Build thread

[bennelson]

There are a few controllers that have a logging feature built in. The Alltrax "AXE" lineup allows datalogging by connecting a computer (laptop in a car) using a COM cable to the controller.



I have the 48V version of that controller on my electric motorcycle, but don't have an appropriate computer to bungie-cord to the cycle!

I have thought that data-logging, combined with GPS info would be really interesting. That way, you could learn how much power is used going up big hills, in higher speed zones, etc.

We joked about this for Toms Neon conversion, which will have a very nice custom battery management system. Seriously though, I think he might be able to integrate GPS with controller data-logging.

[TomEV]

Here's a sample GPS coupled Alltrax log...

[Intrigued]

Hey, while you're looking for battery locations, you might think about re-doing the spare tire area into a dropped-down area that would be much more efficient in holding batteries and electronics. The extra spring power you're using should support them sufficiently.

Alternatively, you might add a box somewhere in front of your spiffy new one, that could hold two or three batteries lengthwise... and shift the weight forward a little...

[jmilk]

Originally Posted by bennelson

I have thought that data-logging, combined with GPS info would be really interesting. That way, you could learn how much power is used going up big hills, in higher speed zones, etc.

We joked about this for Toms Neon conversion, which will have a very nice custom battery management system. Seriously though, I think he might be able to integrate GPS with controller data-logging.

Oh, now you said something. See, I'm stuck with a van (family and all that), and I've been getting 10-15% above EPA in the country by using DWL and coasting in neutral. My wife gets 30% below EPA. Hrmpff. But for better or worse, it's either ICE or Hybrid for the next car -- the grocery store is 10 miles away on 45-55 mph country roads. Just not EV'able, yet.

But I've experimented with my own version of the MPGuino, combining it with a Wii's Nunchuck controller for a tilt sensor, to get an idea of uphill/downhill driving, acceleration, etc. And a TomTom is programmable, so you'd have 3D coordinates, MPG info from the vehicle, a killer-display and SD card storage... record your most frequent routes a few times, and have your PC at home crunch the numbers to tell you how to maximize speed/coast times, or even control the cruise control for P&G.

Dreams... time for things like this is hard to come by, but the technology behind it is relatively simple.

[bennelson]

Originally Posted by Intrigued

Hey, while you're looking for battery locations, you might think about re-doing the spare tire area into a dropped-down area that would be much more efficient in holding batteries and electronics. The extra spring power you're using should support them sufficiently.

Alternatively, you might add a box somewhere in front of your spiffy new one, that could hold two or three batteries lengthwise... and shift the weight forward a little...

Unfortunately, the space in the spare tire well area would NOT be good for batteries because I could not "sink" them into the frame. There is structural stuff under there. It would be a good place for other electrical bits though.

I also don't want to add batteries in front of the box that I have built, (the back seat passenger foot area) because I need to have the driver seat almost all the way back.

I think I can fit another battery or two somewhere in the back, but I need to finish the main battery box before messing around with the rest.

[jmilk]

I spent 4 1/2 days (on and off, not full-time) reading this thread. All of it. Ben, you're amazing! I have lots of projects around the house that have been started, but with jobs and kids and such, it's difficult to get anything completed. Or maybe I'm just a slacker.

I'm also not going to be someone who tells you what not to do, although I have excellent qualifications in not doing things. I do have a few random ideas about this project, which probably aren't new to you.

- As for heat, someone mentioned Webasto heaters. There are a number of small, efficient heaters available, which run on diesel, gasoline, kerosene, propane, etc. In Europe, many passenger cars can be ordered with an auxiliary heater option. If you want something mobile (i.e. not plug-in-before-leaving), given the energy density in those fuels, it's probably your best bet. You might even heat coolant with a plumber's torch...

- Another option would be to create proper heat storage: Take a box, put in a nice long electric heating coil (pipe-heater), add a few windings of copper coil, and pour concrete over it. Then insulate the thing. While at home, plug in the pipe-heater to heat up the concrete. On the road, run coolant through the copper into your heater-core. They use larger systems in the UK and parts of Germany to store "cheap" electricity during the night to heat the house during the day.

- You mentioned something about diodes for the turbo mode. Make sure you use a flyback configuration and size them right, if you're still planning on doing this. At no place in your application should you put a diode in line with the load. Even at the small 0.7V forward voltage drop, pulling 400A still makes it a 280W heating element. Come to think of it, I have never seen (or looked for) a diode that could handle more than 10A. As far as control goes -- but you probably already thought of this -- I'd use a microswitch to take the throttles "kick down" position and turn it into turbo.

- I see MPaul has a nifty OS controller going on. Neat. I wonder what it would take to create an OS charger. Microprocessors are cheap (as MPaul knows), so designing and building an intelligent charger is largely a matter of software these days.

- I'm still thinking about metrics. Like I said, microprocessors are cheap. Wouldn't it be fun to integrate the pwm controller, charger and metrics all in one... the charger would know how the discharge cycle was and could adjust the charging. Possibly charge gentler if you know there's enough time, and more aggressively when you don't. Even just "top off" if you know you just need to get back home for the overnight charge.

- Got the suspension worked out? Aren't the front-springs (motor/tranny weight) stronger than the rear ones? Could be an easy replacement.

Go Ben & Electro-Metro.
-JM

[bennelson]

I'm still working on the suspension. That's sort of on-hold for now until I get my battery configuration exactly worked out.

Why mess with springs when the weight is still shifting!?

I do have an extra set of front springs, and some smaller diameter springs from a Columbia ParCar.

When I get the batteries all in place, I will focus on suspension again.

[bennelson]

Finally got to do some more work on the car.

Last week Sunday, at the EV build day, Rich welded a bead all the way around the back seat battery box.

Also, we replaced both rear brake lines. Nice to be able to stop again.

Finally today, I wire brushed down all the welds and painted them. My supply of Rustoleum spray paint included Almond Appliance paint for the inside, and Blue Hammer Finish for the outside.

There were a few small spots where the weld couldn't go all the way around, so I caulked those spots to completely seal the inside from the outside of the car.

To protect the bottom of the box, I sprayed it down with a coat of "rubberized underbody spray". Man! Somebody should have warned me! That stuff is nasty! I put in contact lenses (so I wouldn't get the junk on my glasses!) put on safety glasses and a dust mask, and sprayed away.

I should have worn disposable arms. I had to bathe in laquer-thinner afterwards!!!

I loaded 5 of the batteries into the back seat battery box and started cabling them up.

Unfortunately, after all my hard work and planning, I really only can sink 5 batteries into the back of the car. I can only fit 2 under the hood without added some custom welded rack that would hold a batt. above the motor. That means I am still going to have 5 batteries on the original bedframe spanning the spare tire well.

It also means I need some BEEFY rear springs. Anyone have the FRONT springs from a Ford Ranger kicking around? (No, seriously, if you do, please let me know....They should fit!)

Were you counting? 5 batteries in the back seat box and 2 in front makes 7 - not a number that really works for me right now.

I hooked up 4 of the 5 in the box in series with the two in front. Right now, I have 6 batteries in series (my original 72V system) plus a hitchhiker who isn't pulling his own weight.

But here's the thing. By adding 5 more in back, I have 6 spares in back, all easily accessible to rig up in parallel with the first 6. Then, I only have to swap two cables to upgrade to 144V.

If I was REALLY brave, I could even make a contactor do it, and have Super-Duper-Uber-Turbo-Boost, but I might get wiplash or brake something. Turbo at 96 volts in 5th gear actually pushed me into my seat...

So, after what, a little more than a month? the car is now able to be useful to me once again! I still need to put the bumper cover back on, so I have my front turn signals!

There are a BUNCH of eco-events coming up in April. I really gotta get my act in gear to have the car looking nice by then!!!

[Christ]

After noticing the rear suspension of your car, Ben, I thought about something... although I didn't take pictures, you may be able to look up what I"m talking about.

When you buy a strut cartridge for the front of a 88-91 Honda Civic, What you get is the actual strut cartridge, with no mounting necessities (you reuse those). I'm thinking that your rear shocks mount through shock towers, right?

The bottom of the Civic's strut is bare, and slips into a "fork" which connects to the lower control arm... I'm pretty sure it could easily be made to fit in place of your shocks in the back.

What is the benefit of that, you may ask?

It's a COILOVER type strut...

What does that mean for you?

No more trying to fight w/ springs to fit them in spaces they don't fit in, or doubling springs inside each other... run your stock springs, a set of Honda Civic coil overs in place of your stock shocks, and you've got one mean rear suspension that should be able to handle whatever batteries your chassis can hold reasonably.

If you need pics, to visualize what I'm explaining (poorly), just PM me, I'll take some next time I go to my storage facility.

[Christ]

To make it even more perfect, your rear strut mounts are nearly identical to all the strut bearings in the Civic... so the Civic's rear coilover setup will probably come pretty close to bolting right into the back of your car. Might be worth looking into, If you happen to find a Civic with shocks and springs on it in the junkyard.