Wednesday, May 6, 2009

Progress Report

The past three weeks have been quiet with just occasional work being done on the car. The weather has gotten really nice much sooner than usual so things like raking and preparing the vegetable garden took priority. On the rainy weekends, I was confined to indoor work only since the car is now outside in our driveway making it hardier to work on in bad weather.

On May 5th, I received several more parts like the ground control coil springs, the PFC3000 charger and some additional 2/0 cable that I will need for the battery connections. The Pak Trakr and batteries are still pending delivery and are the last pieces of the puzzle. Hope there won't be any more delays with the batteries.

Before purchasing these springs online, I shopped around locally and tried really hard to find a good deal. I only needed two springs for the back but this set of four was the best choice out there for the money. They were ordered with 500 LBS of total spring rate added to the rear coils (250 LBS per side) for the additional weight of the battery pack.

Here is the PFC 3000 charger which came equipped with a non-standard 30 amp 250 vac rated three prong plug (two hot wires and a ground, no neutral wire) as well as an SB-50 anderson connector (male/female set) for the DC side. There is a charger interlock connection but I am not quite clear on how this is to be connected yet.

Here is a closeup of the charger status LED indicator.

The charge interlock wire is shown below next to the SB-50 connector that connects to the battery pack.

This is a closeup shot of the seven pin connector that I believe is used to interface with the charger in order to upload/program charging algorithms. In my case, the actual programming of the unit was done by the vendor.

Below is the actual charging profile used for my battery pack. The algorithm used is Alg312, therefore, nominal 3.2V/cell or 128V total, charge to 3.6V/cell or 144V total, max. 3.8V/cell or 152V total.

To catch up, here is what's been happening lately. I mounted the Curtis Controller onto a large heat sink and then made a mounting unit for the fan that will help keep the controller cool. I used aluminum sheet metal bent at both sides and attached it to the heat sink with four small bolts, lockwashers and nuts then mounted the fan to the sheet in a similar fashion but with longer bolts.

The motor compartment needed a bit of cleanup so I wiped it down nicely and began to organise the wiring before preparing to mount the control platform. I dismantled the main wiring harness to identify the wires I wanted to keep and separated them from those I did not need anymore but kept them just the same in a tie wrapped bundle off to the side under the stock battery. I basically kept the ECT sensor and CKP sensor wires from the main wire harness. I found that it was easier to get this done by jumping right in with both legs and arms.

Here is the CKP sensor and what I thought was the ECT sensor. I recently got this off another car but it was brought to my attention that I mistook the Knock sensor for the ECT sensor. I plan to return for other parts soon and will try to get the right part next time around.

Then came the mounting of the control platform in the motor compartment. The platform was already prepared about two months ago but I did not want to install it until I finished the controller fan unit and knew which charger I was finally going to use. The PFC3000 charger that I settled on is fairly large (about 7" tall) so I had to make sure that it clears the hood allowing it to close. When planning for the mounting of the control platform, I also wanted to ensure that there was a good enough slope to the platform in order to evacuate any water that might find it's way in. I made two mounting brackets out of 1/8" thick aluminum (recycled rulers) and also used part of the existing stock battery mounting bracket to support the controller platform.

This is a shot of the throttle cable and a mounting plate I made using aluminum sheet metal. To get the nice square cut out in the middle, I borrowed a nice little tool called a "nibbler" from a friend of mine named Benny. All I had to do was drill a hole in the middle and then nibble away around the hole making straight cuts until I got a perfect square opening for the throttle cable clip to fit in.

On a rainy day, I finished installing some remaining components like the small heat sinks and terminal wires on the cell balancer boards. Each unit was continuity tested at the battery terminal wires to ensure there are no shorts.

I also tested the boards with 3V (green LED lit) and 9V (green + red LED lit) and all checked out well.

In the rear, I installed steel T-bars on the inside of the trunk floor to keep the battery box well supported and in place. I drilled a few self-tapping metal screws to fasten them to the floor. I also drilled two holes through the side T-bars and the floor and fastened two threaded rods (one on each side of the battery box). These rods will serve as a tie down for the battery box with a flat aluminum bar across the top. I wrapped this bar with a layer of electrical tape and duct tape for safety reasons in case it where to accidentally slip into the battery box and make contact with battery terminals. I have since painted the T-bars silver to match nicely with the stock silver color.

A small door was added to the battery box to allow the batteries to be placed inside easier when the time comes.

Next task is to install the rear coils, mount all components on the control board and finalize the connections. I'm probably forgetting something.....More pics to be posted shortly.


Brian said...

Coming along nicely Jim. I like how you did the fan on the heatsink. Mine was a bit of a pain to bolt on making mine flush against the heat sink.

Nick Drouin said...

Looking good, Jim.

The battery charger control output should produce "pack +" when not charging. This can be the source for the KSI input of the controller, which requires "pack +". (Double-check the Curtis manual, but that's basically what I do for my Logisystems/Delta-Q setup).

By the way, I just ran into trouble with the SAAQ... make sure your GVW is well below (GVWR-70kg*NumberOfOccupants) and GAW's are respected (center of mass).

They were rather unenthusiastic regarding my suspension modifications; and you'll want to get a clear statement on requirements for "modified vehicles" which are equipped with airbags.

At the very least, I will need an (OIQ-registered vehicle mechanics and dynamics) engineer to sign off on everything. At worst, I have to undo the suspension mods and return the car to stock weight; in which case I will have to sell the vehicle.

Contact me via email and we can discuss. Things should become clear this week.



Mindaugas Milasauskas said...

Nice progress! I'm curious why did they select 3.8V as maximum voltage? Thundersky's manual says that maximum charging voltage is 4.25V. Was there any reason to choose lower max voltage which might cause cells not to charge fully? Who is more right, Thundersky or guys selling the charger?

Jim and Elizabeth Karamalis said...

The decision to set 3.8V as the max voltage was my decision. I have been speaking with fellow EV converters and we believe that 4.2V is the peak before damage can occur. We feel that going to 4.2 is too risky. The charger vendors will ask you how you want these values to be set or will simply set them based on the data provided for your cells. So, in my case, I provided the values of 3.8 (for max) and 3.6 (for charge to). This does not mean that your higher values are no good. It's just an opinion I guess. Others out there are much more knowledgable than me in this area so I just went the safe route and hopefully the right route.


Anonymous said...

Have you figured out how to wire the A/C 220v and the 110v for the charger.

Lance Johnson said...

I am interested in the charger wiring as well. What technique are you using to disconnect the traction pack from motor and controller when charger is enabled (i.e. charger interlock relay)? I just picked up a charger that does 120V and 220V but not sure which relay to use for this varying AC voltage.