Back on the road

Hey! It’s been a long winter here is Stockholm but it´s finally over. I haven’t been working that much in the Fiat, a new floor pan for lowering drag and a new battery gauge has been installed.

I wanted to get a better view of the energy flowing through the system so I changed my paktrakr for a E-Xpert HV. What I loose is the individual monitoring of each 12v block, what I gain is the possibility to track amp-hours (ah) going in and out of the battery.

I have a 90ah, 76,8v pack. So my total energy is about 6912 Watt. I ran a test today to see how far I would get using 80% of battery capacity (72ah). The test run included both highway, about 80Km/h, and city driving. Traffic in central Stockholm was horrible with a lot of stop & go.

I used my Android to record the trip:

 

The Xpert uses a shunt to monitor the Ah that flows through the circuit. Removing energy from the pack is symbolized by the minus sign on the display below. When the pack is fully charged the meter show 0.0 Ah and as I start to drive the negative value increases. Basically what I did was to drive one way until I reached 50% SOC and then turned around.

 

Google My Tracks gives me the following info:

 

 

The meter on the fiat show 53 km:

start

stop

 

 

So I’ve used about 5530W (80% of my total 6912) to drive 52 km. And I still have 20% more in the battery before it is all empty. That 106 watt per kilometer, mixed driving. Now that’s impressive.



 

 

 

Stay tuned!

Fiatelisten!

Hello in the snow! The conversion of Luigi is featured in a 4 page article in Fiatelisten, the Swedish classic Fiat club magazine. Hopefully I will be able to publish the article on my blog shortly.

 

Merry Christmas and a happy new year!

Interested in marine ingenuity?

As you might know our oceans are dying and the Baltic is now home to seven of the of the world's ten largest marine "dead zones" - areas where there is no oxygen. As a lover of nature I must act upon this. My next project is focused at giving boat owners a choice to propel their boats using electricity in order to lower the environmental impact.

Check out www.wildtech.eu for more information.

Luigi's front page stardom

Luigi made the news!

My conversion is now featured in Sweden’s biggest news paper, almost a full page in the motor section. The article describes the car and also addresses the fact that it is today impossible to get it classified as a "green car". Hopefully this article will inspire others to start similar projects.

You can now read the aticle here: http://www.dn.se/motor/supermiljobil---fran-1973

 

 

The video from my "first" test run can be viewed here:

http://www.youtube.com/watch?v=E5nGnoMznTE

 

 

Good night!

Autumn is here and it's time to put the little fiat to bed. Summer has been good, a total of 75Km has been driven with a kWh usage of about 1,08Kwh/10Km. I still haven’t gotten around to test how far I can go but given that the battery pack contains about 6,48kWh I should be able to go 42Km (using 70% of the battery bank) without having a negative impact on battery life.

The only problem I had was the frying of the Agni. After restoring the Agni and limiting the Kelly to 300Amps it now runs smoothly without overheating.

I'll leave you today with a picture from when I was out working at Telia in Sweden earlier this summer.

Have a good one!

Love and Love

Dear friends and followers.

A lot has happened since the last post. I am now a married to the most wonderful, and understanding, woman in the world, Lisa Wildare. I Love you!

The car is back on the road after changing brushes, brush holder, installing a fan and limiting the current to the Agni.

After restoring the commutator I installed the brushes and set the timing. The default timing marks cannot be used and in order to find the new "zero" I used the following procedure.

Brush holder with brushes fitted by Joztek.
The cardboard helps during installation.

1. Attach the brush holder and tighten the screws just so you can move the brush holder with your hand.

Brushholder from Jozztek, fitted with screws to aid set timing.

2. Apply a low and stable voltage, I used 13.8V from a charger with supply mode.
3. Attach an amp meter to monitor the amps used by the motor.
4. While the motor is spinning, read the amp value and carefully turn the brush holder in either direction. Find the position were the amp reading is the lowest, this is our new "zero". Make a mark on the motor and on the brush holder.
5. Turn the brush holder against the direction in which the motor i spinning. I turned the holder 1.5mm. See the Agni workshop manual for more info.
6.Tighten the screws on the brush holder CAREFULLY!

Let the motor run for 20 minutes or so before steping on the gas.

After the timing was set and the brushes were run-in it was time for a test run. I made a configuration change to the Kelly before the first run. Max amp's was set to 360A. During hard acceleration I could feel the smell of hot brushes so I backed it down to 300A.

I haven’t had time to work on my water cooling of the Agni but I have a lot off fans laying around so I decided to make a cooling fan to the motor. There is not a lot of space left between the Agni and my batteries so I have to put the fan on top.

A (D1238B12B9) 12V fan capabel of pushing 5.25m3 of air per minute.

The fan sounds like an airplane when it's running. The plan is to use a thermal switch that will control the on/off of the fan. For now it's hi jacked into the circuit for the lights. I can't hear the fan when driving.
Air is pushed down in parallel to the Agni's rear plate. As you all know the Agni sucks air through the backplane and out through the stainless ring. In order for the air to get into the Agni I put a small piece Plexiglas in the bottom of the Agni.

The fan on top and the plexiglas in the bottom.

When the fan is running and the motor is still air is coming out under the car. When the Agni starts to spin you can feel that the air flow under the car gets weaker, the more RPM's on the Agni the more air is used for cooling. At max RPM almost all of the air from the fan goes through the Agni.

With the fan installed I hooked up my Ohm-meter to the thermistor in the Agni and went for a ride. The fan, in combination with lower the amps, is working fine. The Ohm-meter never goes below 10KOhm when the Agni is spinning.

Restoration

As you all know I got a bit too cocky chasing Porsches on the highway and the Agni had a brush meltdown. The first thing I needed to do was to get a new brush holder and new brushes. As it turns out one of my friends from the diyelectriccar.com forum is the distributor of Agni in Europe, www.jozztek.com, Jozztek has a deep knowledge of the Agnis and a lot of racing experience as well. I could not reuse any of the old parts so I got the brush holder fitted with brushes. Jozztek matches all brushes so that the voltage drop/resistance is the same between brushes.

Meltdown brush holder

New brush holder from Jozztek with matched brushes

Next thing on the list was to restore the commutator. When the brushes melted there was a lot of arching going on and the surface of the commutator, where the brushes connect, had to be refurbished. In order to refurbish the commutator surface I needed a "grindstone". Luckily I found a company just outside of Stockholm that specializes in DC-motors. www.karma.se has a wide range of brushes and tools for restoring electrical motors.



Commutator before resurfacing

You need to spin the motor in order to resurface the commutator. The RPM of the motor should be around 500 when using the stone from www.karma.se. Jozztek shared his bright idea to use the old brush holder and two old brushes to drive the motor during grinding. Split the brush holder in half and attached two brushes, one negative and one positive.

The Agni gives you 71 rpm/V so if you connect is to a 12V battery it will spin at about 800 rpm. Cut the grind stone so that you can fit it to the commutator. Use a vacuum cleaner during the grinding to collect the dust. You don’t have to apply a lot of pressure to the stone and you will feel when is working. Change position of the stone often and keep it steady.

Stop the motor every now and then and inspect the result. Don’t overdo it!

The picture above shows the commutator after it's been resurfaced. Next on the list is too fit the new brush holder and adjust the timing of the brushes.

Fried!

Just to show you what happens when you push the Agni above its limits:

I need to replace both the brush holder and the brushes. I need to get my foot of the gas and the water cooling in place J

This is a picture showing the armature of the Agni. I might have to prep the surface before installing new brush holder and brushes.

Street legal!!!

After two years of hard work the car is now done! I got "him" street legal today.



Performance modifications

I ran into an interview with the designer of the Agni 95R, Cedric Lynch, on the net and I found an interesting part about water cooling the Agni in order to boost performance. Now I know I'm not ready yet but this is FUN!
Apparently one can run about 50% more power into the agni if these steps are followed:

"It is possible to cool an Agni motor with water spray. The best place to spray is on the inner part of the armature opposite to the side the brushes run on, and you need about 40 millilitres per minute which you get from a 1mm jet fed by gravity with a 250mm head. Turn the water off before stopping the motor, so that it does not remain wet when it is not in use."

This is what I'm looking at right now:

The tank is located 250mm above the spray nozzle. The cooling water is controlled by a solenoid, normally closed. The solenoid is in turn controlled by a bimetal thermal switch, normally open, that triggers at 80C.

It just might work!

Test Drive

Hi all!

It's alive! I've been out on two small runs, only about 60km/h and it sounds and looks good. More data will be posted.

Here is a video showing the car in action:

 

 

Battery Installation

Battery installation

I wanted to get the batteries as evenly distributed in the car as possible. In fact it turned out that I didn’t have much of a choice when it comes to battery installation. I had one rule, NO BATTERIES IN THE BACK SEAT! So that leaves me with the rear engines compartment and the small space under the front hood.

4*90Ah

2*90Ah

Four batteries are to be placed in the back of the car, two on each side of the Agni. The other two are to be fitted just behind the front of the car, where the original 12v battery was located.

In order to support the 60kg's of batteries in the rear I had to design a support beam that also would act as a rear motor/gearbox support. I decided to make it out of aluminum since it is light and it doesn't rust. This also gave me a splendid opportunity to learn how to TIG-weld.

After hours of puddle control practice and 20 liters of Argon I started with the battery frames. These are made in 3mm L-profile aluminum and the will hold the two pairs of batteries togheter.

The two frames had to rest on something and after consulting a friend I came up with a design that consists of a support beam made of 6mm U-profile aluminum that stretches from side to side in the engine compartment.

Rear support beam

The support beam is fastened on both sides of the engine compartment and also has an "arm" that connects to the original motor mount found on the fiat.

The battery frames fits tightly into the frames welded to the support beam and pack straps will be used to keep them from moving up and down.

This is the finished support beam with batteries mounted.

The battery frames and the support beam have a total weight of about four kilos.

Batteries - the achilles heel of your ev-project

What type of batteries should I use? That's a question that everyone involved in the EV-game needs to decide on. It basically all comes down to four things:

    
   · Type of EV

   · Planned usage/range

   · Budget

   · Complexity

Type of EV

If you are converting a boat with a displacement hull you can easily go for lead-acid batteries since that type of boat will normally perform better in the water with large ballast.

I use 100kg of lead-acid in my "double ender" and that works just fine.



Linnéa - equipped with a hybrid powertrain and lead-acid batteries.

On the other hand, if you are converting a motor cycle or bicycle you would not want the extra weight from Pb's and installation space is limited.

Planned usage/range

What is the intended use of the EV, proof of concept, daily commuter or race car? What your desired range 10, 100 or 1000km? All of these things come into count here. There are a couple of calculators available that can help you get an idea of how much power you need to do the job.

Budget

A fat budget makes all the difference. If money is not the issue you can buy top of the line cells from Kokam or A123. These cells can deliver enormous amounts of current and are made of the purest materials. We will go deeper into battery technologies later in the blog.

Complexity

4 lead-acid batteries in series and a 48volt charger, that’s pretty simple compared to a 26 cell Lifepo4 pack with BMS.

Since this blog is about the conversion of a car I guess that it falls somewere in between the two extreems. I could use six lead-acid batteries in the fiat, it has been done before, but it is not optimal. The plan with my conversion is to create a daily commuter that has a minimum range of 50 km.

My Solution

In order to keep the cost and the complexity on a human level I have decided to go with six 12 volt, 90Ah LiFeYPo4 batteries. Now these "blocks" are made up of four 90Ah cells that share the same characteristics.

15Kg 12v 90Ah

The producer claims that these four cells, if not abused, are so stable that the need for individual, per cell BMS, is nonexistent. Now I know you might think that is sound too good to be true, well I'm here to find that out for you.

I will use a simple kind of BMS but its one board per block, i.e. six boards. These "AKUMON" boards will monitor each block and will issue a 12v signal if the charge voltage exceeds 17 volts or if the battery voltage goes below 10 volts. There is also a bleed-function that will limit the current in the last stage of the charge.

The AKUMON board. Provides high and low voltage protection for LifeYPO4 blocks.

The charge to be used is a 3KW (Vmax 87,6 | Imax 32A) Lithium battery charger. The charger will have a relay connected on the power chord towars the 240v grid. If one of the AKUMON's detect a high voltage, > 17v, the relay will open and the charge will stop.

Batteries, charger and Akumon's where all purchased from www.ev-power.eu great service and good prices!

Choice off controller

In order to control the electric motor we need a controller. In its most basic form it interprets actions taken by the driver and adjusts the voltage and current to the motor accordingly. There are as many flavors of controllers as there are types of motors. A good source for finding motors and controllers that work together is www.evalbum.com.

When choosing controller you should, at least, consider the following.

·        Make sure the controller matches your type of motor, DC, AC, series and so on.

·        Make sure the controller can provide the amount of power you need for your application

·        Make sure that the controller is easy to program and that there is some kind of support mechanism that can help you if you get stuck.

I've used the Controllers from Sevcon and Kelly and its two different worlds. First of all the Sevcon Gen4 controller is AC and the Kelly is DC.

Sevcon Gen4 G4845

. Apart from that the Sevcon controller is a state of art controller with more settings than you can ever imagine. On the down side the complexity makes is very hard to program and even if you are a dealer it can be hard to get support from Sevcon. On top of that the programming interface for the Sevcon Gen4 controller costs about $900!!!

The IXXAT 1.01.0087.10200 used for programming the gen4.

Kelly on the other hand uses a USB-to-rs232 cable that you can find in any computer store to program their equipment. Kelly's downside is, if you should believe the word on the internet, their quality. I've never heard so many bad words being said about any controller/manufacturer. I didn’t really choose Kelly, it came with the motor. But I will give them an honest try. I've already started by contacting support and they answer back in a day or two.

The problem I'm facing is that the red led on the controller is on all the time. According to the manual this means that is broken but it seems to be working quite ok. I've put together a document with pictures of the controller and schematics showing how it is connected. It has all been sent to Kelly for review. Programming of the controller is done via a GUI that runs on Windows. In order to communicate with the you need the USB-to-rs232 interface. According to Kelly all external devices, such as motor, throttle should be disconnected during programming of the controller. You don’t actually need the batteries connected as you can supply the controller with a minimum of 18 volts via J1. J1 is one of the two round connectors on the front of the controller. I hooked up a PC-supply to pin 1 (+) and pin 13 (-).

Apply power and connect the db9 connector to the controller. Make sure that you have already installed drivers for the USB-to-rs232 in windows.

The controller should, when booting up, turn on the green and the red led, after a few seconds the red one should turn off.

Start the programming software, you can get it from http://kellycontroller.com/support.php make sure you pick the right software for your controller.

I should mention that this is work-in-progress and all of the settings described here might not be 100% accurate. In other words, don’t blame me if something goes wrong. ALWAYS keep your car jacked up during testing.

This is the first window that pops up after starting the application. I'm going for a basic configuration using a 0-5v throttle as the only external device. The throttle gets 5v from the controller and by moving the lever it returns 0.9-4.10 volts to the controller. The controller also includes a micro switch but we will get to that later.

First of all I specified the throttle effective starting position to 1.2 volts. This means that that the controller won't send anything to the motor if the value from the throttle is under 1.2volts. I l left the throttle effective area end position at 4 volts.

Maximum motor current specifies the maximum current that will be sent to the motor. The value is a precentage of the total current handled by the controller. The 72601 can handle 600 Amps and the Agni has a maximum apm of 300, hence the 50% setting.

! Make sure your battery pack can supply the current specified !

On the second page we will set over and under voltage. These setting are important and will protect your battery pack. These values vary depending on the battery technology used. Get the right setting from your battery supplier.

Another setting on page two is control mode this is how your controller should behave during acceleration. I've always been told to use torque and not speed. Kelly introduces  balanced and I'm guessing I will play around with these values later.

Throttle up/down rate determines how fast the controller should respond to the throttle signal

This is cool stuff, regen, regeneration of energy. Imagine that you are out driving and you run up on a red light. In order to stop you depress the brake pedal. A "normal" car does not have any means of recovering the energy generated during this phase. All the energy that kept the car moving before you pressed the brake is turned into heat. The good thing with an electric motor is that it can be turned into a generator and if your controller supports it the energy from the moving car can be returned to the battery pack instead of going up in smoke. At least that’s the theory of it.

Regen can be controlled in more than one way on the Kelly. I'll start with the simplest setup. When you step of the gas pedal regen will start! This might not be the best solution because it might be wiser to let the car freewheel down a slope then to try and capture the energy generated.

So I found out that if you connect the micro switch in the throttle to the controller you can actually decide if you want to start regen or if you want to freewheel. It works like this:

When you want to use regen you step of the pedal, but not all the way. The trick is to keep the micro switch connected.

If you want to freewheel down a long slope you let the pedal go to its starting position, which means the micro switch will be disconnected. This will deactivate regen.

See http://youtu.be/fEPFgumcJDM for more info.

When you are done with the configuration, click Finish and power-cycle the controller.