onsdag 24 april 2013

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!

tisdag 18 december 2012

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!

torsdag 15 november 2012


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.greenlandhybrid.com for more information.

lördag 10 november 2012

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:
 
 

tisdag 23 oktober 2012

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!

tisdag 21 augusti 2012

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.




söndag 12 augusti 2012

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.