Battery re-installation

After a two months of research and design.  Careful consideration has been put into the BMS system and wiring of the unit and and batteries.  We top balanced the 48 cells and let them stay wired in parallel over the last two months.  Now we are prepared to re-install the batteries and label them for the wiring of the Orion BMS.  We cleaned each cell, labelled them and installed them back into the battery boxes in the correct orientation.  Our next step is to carefully wire the harnesses for the BMS.

Charger relocation program!

We had always kept the Zivan NG-3 charger in the trunk, and this posed problems with heat, and aesthetics.  Plus, we never utilized the "gas" door location for the power plug during charging.  We now have relocated the charger in the engine bay away from the elements, freeing up the trunk area and now allowing for a neater install plus the ability to use the "gas" door for the charge port.  The charger will be integrated along with the BMS, with the BMS controlling the charger at all times.  This should be an interesting journey!

Always something!

     We came to class today only to find that our vehicle lift was sitting in a puddle of hydraulic fluid! The lift has a leaking seal on the hydraulic cylinder. This is a big issue because we can not lift our MR2 up to work on our BMS.   We are trying now to find a replacement lift(donation) or to get this one fixed.  It is an old lift and may have seen its' better days, so a replacement may be in order.
On the plus side our batteries have all stabilized to 3.37 volts after a long charge period, essentially pre-balancing our pack for when we install the BMS.  Of course, we need a lift to do so!  Always something.

Balancing act

We have removed all 48 cells from the MR2 and have wired them in parallel for a balance charge.  As you can see in the picture, we have set the voltage to 3.6 volts and will be monitoring the current as they charge.  As they charge, the current will slowly get close to zero until they are balanced.  No telling how long this will take, but we will be baby sitting for as long as it takes.

Our BMS has arrived!

Our BMS arrived last Friday and needless to say, we are overwhelmed.  The MR2 has to be totally rewired top to bottom to accomodate the new component.  The BMS will monitor all cells during charge and under driving conditions, giving us real time analysis of the Lithium batteries.  This technology will help preserve the lifespan batteries and help to keep them a balanced set.  The performance of the MR2 should be more consistent and we will have the opportunity to data  log our charge and discharge cycles.  Two students are working on a program that will create an interface that incorporates both the Synkromotive controller and the BMS parameters on the same in dash display.
  Today, we began removing all of the Thundersky batteries so we can top balance the entire set in parallel.  By doing this, we will have a balanced pack, and the BMS will have an easier job for the initial few charge cycles.

Brand used transmission

We developed a noise in our MR2 transmission and ordered one from a MR2 message board member in Texas.  We decided to remove the old one after the NEAT Rally.  When we returned, we removed the motor and transmission, cleaned up the new one and replaced the old.  To our dismay, the "new" one had the same sound.  After consulting with our "go to" mechanic, he agreed  that it was one of two things.  Either it had the same issue as the old one, or it is a noise that is inherent to the MR2 transmission.  Well, we decided to replace the "new" one with the old tranny and take the "new" one apart to see what we could find.  Stay tuned....We will take it apart soon and let you know what we find.  On a side note, we are really good at removing the motor and transmission, having done so about 12 times in the past month!

NEAT EV Rally results

The Topsail Electric Vehicle Team travelled to the 17th annual NEAT EV Rally in Northampton County this past weekend at the NCCAR facility. The students competed in seven events and tied for first place overall in the competition. The team had many compliments for their attitude and work ethic. They represented Topsail High and Pender County with class and dignity...as always. One instructor even wanted to take Ryan Mowrey back with him to show his students how to act!  The weather cooperated for the most part, and the vehicles performed very well.  Our truck, nursing a battery with a bad cell was only able to manage 12 laps of the NCCAR 2 mile track.  The Toyota MR2 drove 56 miles in the range and could have travelled another 25 miles but had won the event.  The lithium batteries make a huge difference in the range and performance of the car. 
  We would like to congratulate the NEAT team for their results and thank them and their instructor Thomas Pope, along with Harold Miller, for putting on a fine event.  We look forward to next year!  We will practice the pit crew before the event this time.

The results were as follows:
First overall
Acceleration: First Ranger
Acceleration: First MR2
Range: Second Ranger
Range: First MR2
Design: First MR2
Autocross: First Ranger
Autocross: First MR2
Jeopardy competition: Second