Thursday, October 29, 2009

Last Cables

Running 2/0 cable from the 20 cells in the trunk with plastic cable wrap and plastic straps. Using self drilling screws made it easier to mount the straps but it was still the toughest day on the car yet. The Paktrakr and BMS wiring will have to go on the outside of the plastic wrap with zip ties. This is the home stretch with only wiring the cells together remaining.

Below is a picture of the cables in the trunk under the battery racks.

Steve drove by in his Solar Bug to return a cable crimper.

Monday, October 26, 2009

Cell connectors

The TS cells came with connectors from cell to cell but the connection between each pack of 5 is about 1/2" wider so I made 3 connectors from 5/8" thin walled copper pipe, flattened, drilled and wrapped in heat shrink. They aren't as pretty but should work just fine.

Sunday, October 25, 2009

Vacuum brake pump

This vacuum system is from evsource, which claims it is quiet. I found a good place for the pump and tank and hooked it up. The instructions are very good. It ran for about 40 seconds, was super loud, and then shut off because the vacuum had been reached. So far so good. Then when I hit the brake pedal it turned on again and didn't shut off. Something is wrong. I had to disconnect it from the battery to get it to stop running. They are sending me a new system. Hopefully that will work.

The noise might be a big problem. This pump is rated at 72 db. There is a pump at that is rated at 50db, which might be the ticket.

Saturday, October 24, 2009

EV Dashboard

I've written a Windows CE app, which will also run on a Windows Mobile 5 and 6 device, to display data from the Paktrakr. It reads the data from a bluetooth adapter on the serial cable. I've got it running on a dashboard mounted GPS. On the main tab it displays amps, volts, temp, soc% and kWh. And on the second tab it has a bar chart of the batteries or cells with voltages. It has a simulation mode and can log data to the SD card.

I found a cheap 5" GPS display running Windows CE 5.0 Core with Bluetooth that can run apps. It includes a bracket to mount on the dashboard.
The application should also run on any Windows CE 5.0 Core device with bluetooth including the Magellan Maestro 4250 and the Mio C520. These devices may, however, require renaming some of the installed files.

There is only one USB port on this type of device and it doesn't provide power. So it can't power a serial to USB adapter. Even more, because of limited battery on the device the USB is needed for charging. Perhaps there is a USB splitter that would charge from one side and communicate from the other, but I couldn't find one.

The device doesn't have pairing software for remote bluetooth devices so I had to discover devices and open a stream to the bluetooth device directly instead of through a virtual COM port. I used a IOGEAR Serial to Bluetooth adapter that has an AC power cable (output is 5V and .35A). To get it to work on the Paktrakr serial cable. Hopefully I can find a car adapter to fit it. Then I had to solder a wire between pin4 and pin7 on the 9pin serial cable coming from the paktrakr.
While this wasn't an ideal solution it does work.

Better Bluetooth Cable:
I ordered a couple bluetooth usb dongles from Amazon for 99 cents each. They run the Broadcom 2045 chipset which has very low power requirements. So, I believe it wouldn't be too hard or expensive to build a cable from Paktrakr. I'll be looking for some help with this since it is out of my comfort zone.

Microsoft has a GPS Intermediate Driver (GPSID) that is available on Windows Mobile 5 and later. This allows multiple apps to share the GPS hardware. This GPS device doesn't ship with GPSID and I can't find a way to set it up. So, watthour/mile will have to wait for the "advanced" version.

Friday, October 23, 2009

Tesla paper

The 21st Century Electric Car is a white paper by Tesla Motors. It basically shows that electric drive is more efficient and less poluting than any other drive, including NG, Hydrogen, Diesel, Gasoline, and Hybrid.

Thursday, October 22, 2009

Rack changes

Here are some late changes to the firewall battery rack. A friend is a blacksmith and welded on a couple straps for me today. No plywood is needed and I feel better about how the cell will rest in the trays now so I'll start wiring together the pack soon!

Wednesday, October 21, 2009

Batteries Home

Well, they finally arrived! My original order for 45 100Ah Thundersky LiFePo4 cells was placed with evcomponents in June. While I was told they would be here mid August, I just got them last week (end of October). I've got 20 cells in the trunk, and 25 under the hood. The dimensions are actually what is listed in the specs so the racks are just about right. The connections on top of the cells will be about a half inch higher but I've reserved room for those. Also, the there is room for the vacuum pump and tank, bonus!

Straps will hold them in place.

Motor mount revisited

With the batteries here and the charger on the way it was time to finish the motor mount. I trimmed off the top edges, drilled a couple of holes for the tachometer sensor and painted it.