Archive for the ‘Electronics’ Category

EVView – WiFi Battery Monitoring

Electronics | Posted by admin May 1st, 2012

Working with Charlie Malone from Vintage Voltage, I have been creating a wireless wifi battery monitoring system called EVView™.   The system is comprised of a wifi enabled device that hooks up to Charlie’s Battery Management System and displays the status of every cell on any wifi enabled device with a browser.  The main design is intended for iPad and Android Pad devices that could be mounted in the car for easy monitoring.  Combined with a wifi router and wireless G card the system could also be accessed over the internet for viewing your cars battery status remotely with an iPhone or iPad.

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LiPo – Batteries Terms Explained

Electronics, technology | Posted by admin February 28th, 2011

I came across a great article on LiPo batteries on the RC Helicopter web site.  These guys have been using LiPo batteries with a lot of sucess.   Click here to read the full article.  Below are the highlights translated into values which are more to our using.

Below are some of the values you need to look at when designing a pack.

148 volt LiPo pack = 40 cells x 3.7 volts

Ah – Capacity indicates how much power the battery pack can hold and is indicated in amp hours (Ah).

C –How fast a battery can be charged or discharged. A battery with a discharge rating of 2C would mean you could discharge it at a rate 2 times more than the capacity of the pack, a 3C pack = 3 times more, a 20C pack = 20 times more, and so on.

Let’s use our 100 Ah battery as an example; if it was rated at 2C that would mean you could pull a maximum sustained load up to 200 amps or 200 amps off that battery (2 x 100 amps = 200 amps). The higher the C value the higher the cost usually.  What this means to an EV though is how much power you can effectively use.  If the C rating is low, you are going to have to use more cells to increase the voltage so that you use less amperage.  My car can easily pull up to 1000 amps at 168 volts if I am racing.  Taking off from a stop at normal driving speeds can easily require 200 amps.  Many cells will allow you to pull at a higher C rating for a short period of time without damaging the battery.  If the cell is drained too fast, this usually results in heat which can damage the cell.

Internal Resistance – Most decent higher discharge rated LiPo cells will have roughly 2 to 6 milliohms (0.002 to 0.006 ohms) of internal resistance when brand new. To calculate the total internal resistance of a series wired pack, you would then add these numbers together so a 148 cell pack with each cell having 4 milliohms of resistance will show a total internal resistance of about 592milliohms (0.592 ohms).

As packs age, the internal resistance goes up and the warmer they run. Lower discharge rated packs will generally have higher internal resistance readings.

Now wired with a J1772 connector

Electronics | Posted by admin December 12th, 2010

Finally got around to wiring in the J1772 connector into my car today. The connector end I wired into my 220volt 30 amp circuit in my garage.

The importance of tight bolts with high voltage

Electronics, testing | Posted by admin November 14th, 2010

I learned an important lesson today. I had changed out a few of the Zener battery balancers and hadn’t tightened down the bolts on one of the terminals. When I took the car out for a test run I noticed a bright flash in my rear view mirror in the top of the battery pack. I immediately got off the peddle cutting the flow of electricity and pulled over. What I found was that one of the terminals I had just worked on was blackened and the nut and washer were noticeably damaged by what had been arcing electricity. Without the bolt being tightened the copper plate was loose enough on the terminal that a bump in the road had cause it to jump a bit. The high voltage electricity just jumped this tiny gap producing an arc. Needless to say I cleaned up the terminal, replaced the nut and washer, and the rechecked the connections on the rest of the pack.

J-1772 Charging Connector

Electronics, technology | Posted by admin November 13th, 2010

J-1772 Charging Connector

Thanks to Charles and David from the Gold Coast EAA, I now have a J-1772 charging connector to put into my car.  This new connector is the North American standard developed by the Society of Automotive Engineers for use in all charging stations.  Once public stations are put in, my car will be able to easily get a charge.  The connectors are really nice.  There is a button on the top of the plug that links locks into the charging connector so its not accidentally disconnected.  Simple electronics in both the plug and receptacle do some handshaking to make sure the connection is in place before electricity begins to flow.

J-1772 Connector showing pins

The button on the top has a place where a lock could be inserted

Battery Balancers

Electronics | Posted by admin May 12th, 2010

Lee Hart’s Shunt Type Battery Balancer
12 V Version –

Each battery has a regulator which consists of

2 – ring terminals, with hole for 5/16″ bolt, and crimp for #6 wire
2 – 6.8v 5watt zener diodes
2 – #PR2 flashlight bulb
Solder a zener diode into each ring terminal where the wire normally goes. Solder a 6″ piece of wire to the other end of the zener diode. Solder the flashlight bulb between the free ends of these two wires. Now you have the two zeners and flashlight bulb all wired in series.

Lee added on 8/09 – Since there are two zeners in series, and they have a 5% tolerance, I measure their actual zener voltage, and match them up in pairs with the same total. I have a bench power supply with knobs to set the voltage limit and current limit. I set the current limit to some value like 100ma, and set the voltage limit higher than the zener voltage (like 10v for a 6.8v zener). Connect the zener, and the power supply automatically supplies a fixed 100ma. Measure the voltage across each zener. Sort them into bins (6.5v 6.6v 6.7v 6.8v 6.9v 7.0v 7.1v). Use pairs that add up to the same total
6.5v + 7.1v = 13.6v
6.6v + 7.0v = 13.6v
6.7v + 6.9v = 13.6v
6.8v + 6.8v = 13.6v
Fill the space between the zener and ring terminal with epoxy glue. Likewise, dunk the bulb and its wires in epoxy glue. This makes everything waterproof and acid proof, and helps conduct heat. The zeners get their heatsinking from the large ring terminals and battery posts they are bolted to.

The diodes are all sorted based on the voltages.

The bulb is soldered to the wire and the lead of the diode.

The whole thing is wrapped in heat shrink tubing.  Each end is the same except the diode is reversed.  The positive ends are marked with a red marker.

One of these is made for each battery.

As the pack charges the lights slowly begin to light up on the batteries that reach capacity.  This shunts about a half an amp around that battery to the next which helps to balance the batteries out.  Each time you charge the pack the batteries should get closer and closer.

The charging port

Electronics | Posted by admin March 29th, 2010

One of the last body modifications was the installing of a charging port. I searched all over for a suitable gas door and compartment to house the charging port which in my case is a 125/250 volt 30 amp plug. I found a VW Passat in the junk yard that had a nice setup. The Passat’s gas portvand door can easily be removed and is all one Peice and not built into the body as most gas doors.

Dash and in car computer

Electronics | Posted by admin November 29th, 2009

Spent the last four days, between eating turkey, working on the wiring and dash board. You don’t have any idea how much wire runs in a modern car till you wire one yourself. Finished the electric windows, trunk locks, remote door locks, lights, turn signals, and most importantly the touch screen monitor and computer.

Andrew McClary
Post From My iPhone

Creating an air intake for the controller radiator

Electronics | Posted by admin September 25th, 2009

The Zilla DC motor controller is a liquid cooled system.  It uses a small radiator to cool the coolant which is pumped through the system.  I wantd to create an air intake and duct system to help cool this system.  Though it will also have a small fan, hopefully I won’t need it.

The GT body already had air scoops designed in the body.  One of these was cut out for this use.  A duct then needed to be fabricated to match up to this air intake and transfer air to the square radiator.  This I fabricated out of fiberglass.

Step 1 was to create a cardboard mold. This mold was covered in duct tape and fiberglass cast over the top of it.  Below you can see the mold on the right and the fiberglass peice on the left.

2. Sand the peice and add a little filler to make it look more finished.

3. The radiator is bolted onto the duct.

4.Bolts were fiberglassed into the body to attach the duct over the air scoop.

5.A mount was also fiberglassed in to hold the pump.

Wiring Diagrams

Electronics | Posted by admin July 10th, 2009

These are the working drawings of the electronics that I have worked out. They have not been tested yet.

Here are some photos of the connections.

Battery Tie Downs and Linking

Electronics | Posted by admin July 6th, 2009

Now that I had the batteries it was tine to finish up the battery racks and create tie downs for the batteries. Securing the batteries in my mind was the single most important job in making this a safe car. Since the driver sits so low in the car, most of the batteries are sitting right behind the driver. Making sure that the batteries don’t get loose and move forward is important.

I originally had looked at using straps with ratcheted ties. I then looked at metal bands. In the end i used 3/8″ rod and bar steel frames on top.

High Voltage Wiring

Electronics | Posted by admin June 21st, 2009

With the batteries here it’s time to start working on the high voltage wiring. Unlike the normal car power which is 12 volt and grounded to the frame, the high voltage traction power must be isolated. Because of the high amperage all of the wiring will be 2/0 electrical cable.

The first part was to map out where all the batteries are going to go and how the current will be routed. The positive ends need to be next to the negative ends so they can be easily routed with the least amount of wire. 2/0 cable is expensive stuff so measuring well will save money.

The cables all get connected with wiring lugs. These are crimped on with a special hammered crimper. You have to be carefull when you strip the ends not to cut any of the small strands that make up the cable. You also need to be carefull when putting on the lug that all of the strands fit nicely inside. A good wack on the little crimping device with a large hammer makes a good strong joint. The ends are then shrink wrapped with shrink tubing to keep out moisture.

The next step was to look closely at the wiring diagrams provided by Cafe Electric for the Zilla controller. I redrew their diagram to better fit the placement of my components in my car. This excersize also helped in my understanding of the logic and how the system would work. I am going to use two contactors. The main contactor is a Tyco Kilovac. I want to be able to go in reverse without shifting so I am using a special reversing contactor that is actually a dual contactor. This will reverse the field on the motor with the flip of a switch.

Batteries included

Electronics | Posted by admin June 20th, 2009

After a lot of research I decided that the best the best use of the space would be to use a group 31 battery.

Last Saturday at the EAA meeting Lowell Simmons told me about a gentleman up in Melbourne who had a set of 12 Odyssey 12volt 100ah deep cycle batteries for sale. The batteries were purchased by the gentleman named Gerald Wagner for a EV project which unfortunately he would be unable to complete because of illness. Gerald was the author of Electric Vehicle Conversions. The Hawker Odyssey batteries were out of my budget and I am really a few months away from being ready for them, but I thought I would give the man a call and see. This morning I called and we were able to work out a deal. So I drove up to Melbourn with my son to pick them up. My Toyota Previa van was loaded up. At 75 lb each this was 900lbs. The van was heavy but seemed to drive well. All was good till about 4 miles to the exit off the turnpike. The road felt a bit bumpy but a few minutes later we realized it wasn’t the road when one of the rear tires blew out. Not sure if it was the weight, but sure it didnt help. Unloaded some of the batteries and changed the tire, the loaded them back in and made it home safely.

The batteries fit perfectly in the racks I had created. I have room for 4 more batteries if needed. I am going to get the car running on the 12 at 144 volts and see how it performs. If need be I can always add the additional 4 latter.

Installing the electronics

Electronics | Posted by admin April 18th, 2009

The battery racks

Electronics | Posted by admin April 9th, 2009

The motor goes in

Electronics | Posted by admin April 5th, 2009

The Warp 9 motor is lowered into the car for the first time.

It took taking it in and out a few times and making adjustments to the motor mount rails to get the motor perfectly lined up.

The motor is in place and lines up with the shaft.  Angle Iron is cut and drilled to bolt into the motor face.  Once the coupler arrives and everything fits, holes will be drilled and these brackets will be bolted in place.

Here the coupler is in place.

A close up of the great bracket that Lowell Simmons machined for me.  I met Lowell at the Florida EAA (Electric Auto Association) and he has been a great resource.  He teaches a shop class to some local high school kids and has them doing electric conversions on cars and even drag racing them.  One of his kids recent projects, a Porsche,  was faster off the line than a Tessla at the 2009 Battery Beach Burnout.   Its going to be interesting to see what his students end up building once they graduate.

This end  is actually my old clutch plate machined down and inserted in.  Great job.

With the coupler in place, the rest of the bracket was fabricated, painted, and bolted in place.

The wires on the motor were rigged up to test the motor.  (These will be replaced with larger cable before the car is running on full battery pack.) The motor was tested by hooking a 12 volt battery directly to the motor with the car up on jack stands.  Everything ran great and had a really cool electric whine.  Can’t wait to get the whole traction battery pack installed with the Zilla controller.

The Zilla Controller Arrived

Electronics | Posted by admin February 5th, 2009

The Zilla 1K HV arrived yesterday. I spent the evening reading through the manual. It is a neat little peice of electronics.

The dash board

Electronics | Posted by admin January 21st, 2009

The Motor

Electronics | Posted by admin November 17th, 2008

The motor for the car is a Warp 9 DC motor. At a hundred twenty five pounds this motor is a little power house.

It is a 9.25″ diameter, series wound DC motor with a double ended shaft.

Standard Features

  • 9.25” diameter, series wound DC motor
  • Weight, approx. 156 pounds
  • 32.3 HP (72 Volts, 335 Amps)*
  • 70 Ft. pounds torque*
  • 5,500 RPM’s
  • Double or single ended shafts
  • Advanced timing – factory set for CCWDE (CWDE available)
  • Industry standard mounting and bolt configuration
  • Commutators key locked onto the shaft
  • High quality, large style brushes, factory preseated over 90%
  • Exceeds Class “H” insulation
  • Drive and tail shafts keyed with pilot bearing hole
  • Delivery – from stock

Choosing a controller

Electronics | Posted by admin November 6th, 2008

If the blood of an electric car is the batteries, it is the controller which is the heart.  This unit controls the amount of electricity that is feed to the motor controlling how fast it will go.  Selecting the right one is important.  After carefull research I chose the Cafe Electric Zilla.  This company has been building the best controllers for years and all of the fastest electric cars on the race circuit use them.  Unfortunately the owner has decided to shut down the manufacturing of the units and only a few remain.  I have a deposit on one of the last ones.

Below are the specs from the Cafe Electric site.

Zilla Z1K

Zilla Z1K

The Zilla is by far the most powerful motor controller available for Electric Vehicles.
Exceptionally high power density has been achieved by a novel design which pays careful attention to maximizing efficiency. Many years of development, extensive testing, and using only the best parts insures reliability.
The result is a race tested reliable package like no other.

In addition, it’s a controller that can make your EV wickedly quick.

While designing the Zilla series of controllers much attention was given to safety. From carefully monitoring that the controller comes up to voltage, communicates properly and checks the integrity of the output stage before engaging the main contactor, to the dual microprocessors that cross check and each have independent means of shutting the system off, there is no other DC EV controller that approaches this level of security.

The Zilla is the only controller that allows adjustment of multiple limits on battery voltage, battery current, motor current, motor voltage, RPM and more. These are not only important for going as fast as possible without blowing up motors and batteries, but also allow adjustment of the unit to prolong motor and battery life in street applications.

The Zilla works excellently with single motor systems, but realizing that many of the quickest EVs use dual motors, the Hairball interface also has a option for safe automatic Series/Parallel shifting of dual motors for even more power and efficiency.

It is no surprise that all of the worlds quickest Electric Vehicles use Zilla controllers, but the safety features allow them to also excel in street applications. The Z1K in particular has become very popular for street conversions due to its superior feature set and low price.

Zilla Specifications

  • Maximum nominal input voltage range for Lead Acid batteries: 72 to 348 volts.
  • Absolute maximum fully loaded input voltage range: 36 to 400 volts**
  • Maximum motor current at 50°C heatsink temperature: 2000 Amps for Z2K, 1000 Amps for Z1K
  • Maximum Battery Current at 200V: 1900 Amps for Z2K, 950 Amps for Z1K
  • Maximum Battery Current at 300V: 1770 Amps for Z2K, 885 Amps for Z1K
  • Maximum Battery Current at 400V: 1600 Amps for Z2K, 800 Amps for Z1K
  • Continuous motor current @ 50°C coolant temp & 100% Duty Cycle: over 600 Amps for Z2K, 300 Amps for Z1K
  • Peak Power: 640,000 Watts for Z2K, 320,000 Watts for Z1K
  • PWM frequency 15.7 kHz
  • Power devices IGBT
  • Voltage Drop: < 1.9 volts at maximum current.

** At this time we are suggesting not exceeding 375 volts on the EHV models, we hope to bring that back up to 400 volts with further testing

Features of the Zilla controllers

  • Simply, the most powerful controller in the industry, by far.
  • Backed by over fifteen years of experience making the worlds quickest controllers, plus a factory warranty.
  • Water cooling for sustained high power operation.
  • 2000 motor Amps available with proper cooling for Z2K, 1000 Amps for Z1K.
  • Multiple Microprocessors which cross check for security and safety.
  • Full motor current limit control with smooth temperature cutback.
  • Silent high frequency operation.
  • Compact size.

The Car Arrives

Electronics, Ideas, Research, Restoring and Building, The Car Arrives | Posted by Andrew September 1st, 2008
After months of searching for a car to start with one is found.

After months of searching for a car to start with one is found.

After months of searching for a good base to start with I found a Ford GT40 replica that was being sold on eBay that was only about an hour away. The ad was found while I was sitting on the beach browsing the web on my iPhone. A bid was place and the following Saturday my wife, kids, and I went up to Jupiter, FL to pick her up.

Its a 1969-70 Fiberfab Valkyrie kit car that was never finished. It had a non-working Chevy V8 engine with a Corvair transmission and suspension system. The frame is a Fiberfab factory frame. The body was in good condition but the front suspension was in horrible shape. The main suspension cross member was almost completely rusted out. This was going to be a big restore and build before I ever got to the electric part. Like I wanted though, this was my chance to do a almost complete ground up build. The car is light, has a strong frame and is aerodynamic. Its also just plain cool.