Tuesday, July 1, 2008

I Can Almost See the Light...

June 23 – July 1, 2008

It was a slow week in terms of getting things done, but that’s what happens when you get toward the end of any project. There are still a million (ok – maybe a hundred) things to do, but each one seems to take forever. All of that old Ice wiring is still bugging me. Our local library has a subscription to http://www.alldatadiy.com/ so it might be worth checking to see if yours does also. They (alldata) will gladly take your money (about $20.00) to get this info online for your car, but I’m cheap. Their wiring diagrams are very detailed and I got a few select sheets to compare to Chilton’s and Haynes. All I (and most people doing a conversion) really need is to get power to the fuse panel so it can run the lights and basic stuff. I also need the key switches (start and run) to tie into the Vehicle Integration Module. I found one wire that was hooked to the starter and was supposed to be the keyed start wire, but after checking it with a multi-meter I am not so sure. To make things easier, I installed to distribution blocks – one positive and one negative. Both blocks have 4, 8 gauge points to tap off of, so when I find the right places to tap into, I am ready. Both blocks get the auxiliary battery cables hook to it. I also took the time to build a new battery box for this auxiliary battery. The old one had rusted away and I did a quick (and poor) job several months ago to keep it from flopping around – now it is in great shape made out of aluminum. As I said, there are lots of little things to do.

With all of those wires out of the way, I installed the rear racks. I already had them in once, but needed to modify the one over the motor with an extra brace. With it in, they were both ready for batteries. The two batteries over the motor dropped right in, but the other two in that rack did not. That extra brace I added was in the way – by about a half an inch. Drill another hole and get a longer bolt and it was in. For all of the battery box connection to the frame I used what are called ny-lock nuts. These nuts have a little nylon insert in them that works like a lock washer – it keeps the nut from vibrating off. The big advantage over a lock washer though is you do not have to make a real tight connection. So when I went through some frame points, I only tighten them enough, but not too much to crush frame and body parts. With all rear batteries installed, it was time to pad the batteries with the Coro-plas – I really like this stuff. I am not sure if it has any insulation value, but I will find out more about it this winter. I have been shopping for some cheap battery hold-downs without much luck. I will probably fabricate something at school.

I mentioned last week how low the front of the car was after putting six batteries up front and this has bugged me every since I did it. I originally wanted to put air shocks in the front, but couldn’t locate ones that would fit. So I did the next best thing and went shopping on Ebay. I knew what the top and bottom fittings looked like and spotted a pair on Ebay. The guy I bought them from has a specification catalog and match sizes for me and found something that will work. That’s on the agenda for this week when they arrive and will update later. All I really need is about 1.5 inches higher to give a little life back to the front springs.

And now to the battery wiring - just another thing on the list of things to do. My brother (the electronics genius in the family – I am just a “wanna be”) convinced me to use flat cable between the batteries. This is the same thing you see that is used as a grounding strap – a flat, braided cable. I found some really big stuff at the surplus store in town and decided to use it just for the short runs. It’s very flexible and just to be safe, I doubled it. Now what I am about to say will spark great debates out there among the EV community, but I am a solderer, not a crimper. If you are a reader of EVDL, they debate this subject at great lengths. Some believe that the only good connection is a crimped connection and some are very specific about what type of crimping. Others swear by soldering, and some ride the fence and say the only good crimped connection is also soldered. I feel a good soldered connection, like a good weld, will always work. It gives 100% contact with the wire and connector and it also “wicks” up the wire a bit to make it even stronger. The cable stays flexible in the middle to keep it from failing (breaking or bending) and unless the joint/connection takes some major heat, the solder will not melt. So as I said, this is a very debatable subject. You can see from the pictures that both types were used up front. The other cables are 2/0. All of the connectors you see are homemade. I used 1/2" and 3/4" copper tubing for each connection. I have some 2/0 connecters to use on the controller, but again, these homemade connectors are solid copper, and a lot cheaper than lugs. I added heat shrink (color coded) to each end just to pretty things up. The small gauge wire at each terminal is for the battery management system (BMS). There will be a circuit board added to each battery when they arrive and this was saving a step down the road. I know I mentioned this earlier in the blog about planning out how each battery connects to another, and it came into play again today. Positive to negative – positive to negative – it sounds so easy. When they are all in a row, it’s so straight forward. But just try to do it when they are in the boxes. Add the extra confusion of front and rear boxes and you have to be extra careful. You hear horror stories of an errant wrench or socket handle arcing across two terminals – well one of those homemade copper lugs (or one of those high priced ones) will make a nice 4th of July show if you make a mistake. And it might be hard to convince the battery store that it “wasn’t my fault” – and at $150-200 each, it might prove to be a bit expensive – be careful!
I have the two long runs to do next to connect the front batteries to the back and build a box for the main fuse and contactor.

So until next week….

1 comment:

Mark W. said...

Hey Bob,

Thanks for the great blog. I have been inspired by your saga to start my own EV conversion and have chosen the Fiero as well. I have a million questions (okay several) but I can start with one. When deciding on the adapter plate design, did you consider removing the clutch entirely? Some EV conversion folks say that shifting sans clutch is pretty easy with an electric motor.

Thanks in advance...you can email me directly at mwrich (at) gmail.com if you think we may be able to trade some resources.