Friday, April 25, 2008

Gas Prices are Criminal!

Well, I just drove by the gas station today, and the current price of gas is $3.57 a gallon!! I still have a few weeks left of the semester and probably going to need another two or three fills ups at bank-draining prices!

So in the past week or so I have had about a whopping 5 minutes to work on this project, and in that time I changed the wire on the PB5 throttle from a two wire to a three wire cable.

Today I hope to work more on the motor plates and adapter, and I am still waiting for a piece of keyway to come in so I can have a better idea of what needs to be done. I have started to make some plate templates out of plywood I have lying around but I think I am going to have to bring the transmission and motor to a machine shop and let them have at it. The real trick is finding a place that wont cost me an arm and a leg. I got a quick quote from a local shop, but I am still going to look around since the end product would cost me more than I currently have.

I also have been recalulating my battery needs, and the battle between weight, total costs and range is being fought. So far, I think the 12 volt is winning with a 35 mile range, 480 LBs of lead and a $500 price tag for all eight of them. Also, charger 12 volts is easier than 8 volts.

Thursday, April 17, 2008

Bump in the Road...

Well, I just found out that I can't charge at my destination, so those 8 volt batteries are looking mighty welcoming right now. I was hoping to use 12 volt deep cycle and getting in a 3 hour charge, but now it looks like I have to figure out another way. The 8 Volts should take me 35 to 40 miles per charge in my hilly area at reasonable speeds (35 to 40) to about 80% DoD.

I have spent the past hour or so playing with the EV Calculator and imputing data from similar EVs and comparing them to mine and like what I see. I have been looking at 72 volt EVs for comparasion, punching in their data, then use that same data for mine, input my EV specs and voltage and getting 35 to 40 miles per charge.

I am also thinking about hooking up some small solar panels for some day time trickle charging, mainly to keeps the volts up for acceleration since they won't be powerful enough to actually do much charging.

Wednesday, April 16, 2008

Finally Some Free Time...

I finally had some free time today, so I hooked up the controller again to the motor and did some actual testing. Things went great, I got about a good 15 minutes of testing in before my old crappy battery gave out. I did an earlier test on Sunday which went well, but I fixed a few things to improve it. Now it seems to be working great, and it barely was warm. The only thing left to do if finish up the back end to it with proper connectors and it will be done! It does have a primitive current limiting, but it is set to 250 AMPs, and I will be keeping it much less than that to save the batteries. My guess it that it will be drawing around 50 to 75 AMPs from the pack when cruising at 40 MPH.
I am still tweaking the design for the motor coupler, but since school has been busy I haven't had a lot of time this past week to work on this project. I am making a package of sorts that I will be giving to local machine shops so I can get a qoute on the part.

Wednesday, April 9, 2008

Coming Along..

Things are slowly coming along. I am almost done designing the adapter system and I have built another controller circuit.

Another EV'er wanted in on my controller project so I am building him one and have most of it done. I am however lacking in the proper casings and terminals but he may be able to come up with something. I have also been looking at the battery situation again. I am trying to make sure I get the range I need, so I am now looking at 8 volt batteries because of the higher Ah rating. In order for me to go a safe 35 miles per charge, the batteries should be rated at 164 Ah, and most 8 volt batteries are 170 Ah. I really need to take a trip to the local wholesale stores and see what they have for inventory.

Wednesday, April 2, 2008

Looking Back...

Programming is definately not my thing. After what was about 6 or 7 hours of reading up and tutorials, I am going to put off the programmable controller for a while. I already have a completely hardware driven controller design that I am going to use, and building into a small metal box. I still have about 6 weeks of the semester left, so a lot of my time will be with school, finishing the current controller design and my motor adpater system.

I have to mention that I am a great fan of Dumpster Diving. Most of my EV parts so far are either surplus, or coming from trash piles. I have gathered a considerable amount of copper to use for the buss bars on my controller, along with a few very nice (new) metal casings that were destined for the scrap heap since the companies didn't like them for some reason. Heatsinks, cabling and other misc parts also were from the junk piles.

When I first considered this project around last July, I made a spread sheet and listed what everything would cost, including the car. I started off with a price of $6,000 and spent the next few months finding ways to decrease it.

Well, about 8 months later, I have spent $1550 on this project (Including the $600 Civic), and the only things left are cabling, motor adapter system and batteries. DIY really got me going, and building my own controller saved a mother load of cash.

Tuesday, April 1, 2008

Simple is Nice

While I am waiting for my transmission Flex Plate to arrive on Thursday I decided to take another crack at PIC programming for the second edition of my controller. It's actually not nearly as hard as I originally thought. I am trying a few tutorials and getting the basics down, but this controller will be simple to start. I am taking two inputs, monitoring them and then sending out the PWM signal to the IGBT driver. The inputs are Throttle and Current sensing. In the future, I will add a digital thermometer to monitor the temperate and hopefull an LCD screen for status. But that's only after the basics are done.