Ben Nelson's Electro-Metro Build thread

[nelsonway]

/opening scene ..Ben (hood over head, face in shadow) sitting in-front of an impressionable class.

/cue imperial music..

"Who here would like to know about the Killa-cycle and the power of PLASMA!"
muhahahahuuh...
Come children, to the electric side and I will grant you torque beyond your wildest dreams"

/fx... purple glow of power

[bennelson]

BEHOLD! MY 72 VOLT POWER!!!

[robbiewt]

And now kids all over the mid west will start farting into their parent's gas tanks.

[Intrigued]

Originally Posted by MetroMPG

Way to represent, Ben!

I have to admit I've declined two invitations to talk to schools about the ForkenSwift (one high school, one college level). Not a big fan of public speaking.

If you're like me, the magic word is "pre-record."

[bennelson]

The other day, I was able to get a used 72V charger in unknown condition, but the cost was right (free!)



This charger has both a 12V and a 72V output on it.

I wired up a power cord for it and tested the outputs. The 12V out was sending about 13.5 volts, but the 72V output wasn't doing anything.

I have been told that many higher voltage chargers don't do anything unless they are hooked up to the batteries, so it was time to rig some up.

I pulled out my "second-string" of batteries and lined them up in the garage. I dug my pile of forklift cables out of the snow and found some with terminals on both ends.

I strung the batteries in series with the forlift cables and then hooked up the charger.




Measuring the string of voltage, the multimeter read 75.4V, which comes to a little more than 12.5V each, which isn't bad considering that the batteries are just sitting in my garage, and it's still cold out. (1℉ right now)

When I turned the charger on, the Killawatt measuring it only went up to about 20 watts. I'm sure that's just the power used to run the two fans on the charger.

I heard a few clicks once or twice from inside the charger. Something's not quite right with it.

Maybe at the next EV Build Day, I can have some of the other guys take a look at it.

If nothing else, it's a free 12V charger.

[MPaulHolmes]

Ben, I hope you write a book some day. It's really fun to read what you write. It sounds like the class trip went really well.

When my first bike charger broke, I opened it up, and there was a black burn spot where the copper path on the PCB had been severed. It was pretty easy to spot. Your charger's problem might be really easy to see once inside. I bet it can be fixed.

[bennelson]

Did I mention that school thanked me for my presentation with a Gasoline Card?



Shell stations? Are those even any of those around here?

I looked up locations on a web page. The closest one is 14 miles away....the wrong direction!!!!

I will just have to leave the card in my glove box and keep it in mind for the next time I go that way!!!

[Tango Charlie]

That's highly ironic, given your goal of getting off gasoline. Isn't that kinda like giving a 'recovering' alcoholic a gift card to the local liquor store?

[bennelson]

Think of it more like a nicotine patch.

I know I am going to go through a little more than $25 in gas before I get the whole bio-diesel thing going, so I'm ok with it.

[bennelson]

Yesterday, I cleaned up one thing that was bothering me for a long time on the car.

I tucked the umbilical cord.

On the back of the car, there has always been a loop of flexible conduit that hangs down in back, and is easily visible. This is one of the few things that makes the car look "weird". The lack of radiator is hardly noticeable, and nobody even misses the tailpipe, unless you tell them to look for it.


(Note the loop of grey "hose" directly under the license plate.)

The "umbilical cord" is a section of flexible conduit with household AC wiring running inside it. Even though you can't see most of it, this conduit is on the OUTSIDE of the car. It runs from the gas cap charging connection to inside the spare tire wheel well, where it connects to both the 72V battery charger, and power to the front to run the 12V car battery charger.

The reason why the conduit pokes down in back is because it goes straight up through an existing drain plug in the bottom of the spare tire well. That means that I didn't have to drill any holes, and even if water got in there, it would just drain back out. However, the conduit does not have enough flex to make the right angle. Even if it did, that would make it very difficult to fish the power cabling through.

I unwired the charger, power cabling from the rear, and power cabling to the front. It's amazing how physics change when it's cold out. Instead of peeling off, the electric tape just about shatters instead.

Once I had the wires all sorted out, I yanked out the hose.

I grabbed a 7/8th spade bit and my drill, and drilled SIDEWAYS into the wheel well as high as I could.

Wrestling with the cold-stiffened conduit, I was able to manage it through the new hole and pull the wiring through.

I yanked the wiring up and put it all together.

Then I tested the wiring and plugged the main charger in. No sparks, no explosions. Just started charging right up.



In this photo, you can see how tight the conduit goes through the hole. It still should get a bead of caulk around it, but I didn't think any would stick in the salt and cold right now. I will try to do it once temps get above freezing again.

Down and to the left of the conduit, you can see the drain hole where the conduit had gone through. I have the rubber plug that needs to go back into it, but I need to pull the batteries out to be able to get to it.

In this view:

you can see how nicely the conduit is now hidden from view. You also have a nice view of where there ISNT a tailpipe.