Wednesday, June 30, 2010

First Day Drive Report

The first day on the road was nice in many ways, but had a few drawbacks that I'll discuss in a moment.

The car is quieter than ever. The new vacuum pump seems to have two stages. The first stage, and loud one, seems to draw the vacuum down pretty quick, but then it switches to a different mode where it becomes much quieter and to finish the job. It's important to note that when I say "loud stage", that is relative. It is still 1/3 as loud as the old pump. The nice thing is that it never seems to go all the way back to the first stage in normal driving. It just kicks in with the second stage when I hit the brakes. It's so quiet, I can't hear it in the car. I can feel it in the floor, because it's mounted very near my feet, but I can't hear it at all. I couldn't be happier with the new pump.

The drive line is beautiful. There is no wobble, which I expected, but it's actually smoother than before. I'm not sure if this is due to the fact that the motor is better balanced than before, or because the flywheel is absolutely balanced now. My bet is on the flywheel. In either case, it's great!

On the very first drive, I pulled into a local shopping center, and a mother was waiting to cross the street with her little girl. They paused and waited for me to pass, and I parked near by. The mother then told me that her daughter thought my car was very pretty. I thanked her and told them that it was also electric. The mother stopped dead in her tracks and said "You're kidding." "Nope!" I replied. She simply said that it was cool and amazing. A nice little interaction.

Now for the rough bits. Driving in Phoenix, in the summer time, at 1:30 in the afternoon, with out AC sucks. There is no other way to put it and no way around it. It was 110°F in my back yard before I left, which meant it was easily 115°F on the black top. It takes almost no time at all for a person to get really sick of that.

Apparently, the Zilla does not like it either. Towards the end of the trip, I noticed the "Check Engine" light flashing slowly. While I can't say with certainty that it was caused by high temperatures, based on a number of factors at the time, it certainly seemed it. I didn't have a chance to get the error codes off the hairball before they'd been pushed away by different ones (I was doing a little experimenting). But I did put my hand on the controller to check and found that it was too hot to leave my hand on it. I measured it with an infra-red thermometer and found it was a 126°F. I verified the pump for the water cooler was working and the fans mounted to the small radiator were spinning. All is working, it's just too damned hot.

Sadly, adding AC to the system is only going to make things worse. I have no where to put the radiator for the Zilla except for behind the condenser for the AC system. So if that starts spewing out heated air from the AC system, the Zilla will over heat for sure.

The DC to DC converters continue to run their fans non-stop. The ambient air temperature, coupled with the heat they generate while operating must be above the temperature threshold. I'm not sure I can do anything about this. I'm going to prop a fan on a chair and point it straight into the back of the trunk. If they shut off, I know I simply need to find a better way of circulating air through there. If they don't, I'm not quite sure what I'll do. I let them run for 12 hours and found the fans and the DC to DC controllers sucked a full 500 W/hours from the main pack.

I'm still working on getting data on which will be the best way to go with the 12V system. Should I disconnect the DC to DC converters when the car is off, or the SLI battery? I have two pieces of data now. The one I mentioned in the last paragraph, though it's important to note that this was with the 12V SLI battery disconnected. If I shut down the DC to DC converters and let the battery handle the load, the car draws off only 44 W/hours. That tells me two things. One, at first glance relying on the SLI battery would seem to be the way to go; and second, these Iota DC to DC converters are energy hogs! I have more data to gather though before I make my final decision, and I'll share that later.

Tuesday, June 29, 2010

We're Back On the Road

I finished up a few things with the car this morning and then began the process of taking it down off the jack stands. Once it was on the floor, I started it up and drove out of the garage. No problems, on issues.

I took the car for a little 3 mile run, just testing out the drive line. It is as smooth as silk. No wobbles, and it shifts beautifully. What a relief and what a great feeling! I brought the car back and plugged in the charger. While I'd been working on the car, I'd made sure to keep the batteries at 50% capacity, which is the recommendation if you're going to store them for over a week or so. So now I need to charge them up.

I'm definitely going to have to do something about the 12 VDC system. The DC to DC controllers have decided they don't like the ambient air temperature here in Phoenix in the summer, so they run their cooling fans constantly. That could be a real problem if I park the car for a while.

I decided to simply disconnect them when the car was sitting idle over the weekend and let the small SLI battery take the load for any 12 VDC demands. In the 64 hours that it was running the show, it dropped from 12.8 VDC to 12.0 VDC. I need to figure out how much energy was consumed during that time. There is a lot to consider and a lot of data I need to gather before I decide what I need to do. But for the mean time, I'm going to have to watch the traction pack when the DC to DC converters are on, or watch the small 12 v SLI battery if I disconnect them. I'll keep you all posted.

But these are minor issues. The EV Z3 is back on the road!!

Friday, June 25, 2010

All Systems Go

I ran a final check of the 12v wiring this morning, and after I was convinced everything was OK, I connected the 12v SLI battery. The car came to life just as one would hope. All systems checked out. With a couple minor adjustments, the 12v system was healthy and ready to go.

I ended up needing to move the proximity switch for the power steering pump about 1/8". The power steering pump wasn't cutting off. I also had so shim the aluminum plate that the vacuum pump sits on because it was rattling and making a lot of noise. I shimmed it, and anchored it down, and now the new vacuum pump is so much more quiet than the old one. It was worth every penny.

Once I was happy with all the 12v systems worked, I turned my attention to the high voltage system. I double checked everything and threw the breaker. No big arcs, and no loud pops, so that's good. It was time to start the car up. A twist of the key, a click of the main contactor, and the car was live. I gave it a little throttle and the wheels started spinning. Excellent!!

Now for the real test. Was there any more wobble in the drive line? I revved it up to 4000 RPM and... smooth as glass. Then I ran it through the gears to be sure the clutch was working OK. Everything checks out.

I have a few more things to do before I take it down and drive it. Unfortunately, no time to do any of that until next week. *Sigh*

Thursday, June 24, 2010

Good Progress

The batteries are all in place and anchored down.

Here's a shot of the front with all the batteries in place and anchored down. I've run new testing wires from each group of four batteries up to the little bus bars that are anchored on the back of the front rack and the front of the back rack. I've included a 2 amp fuse in line on each lead from the positive side. Any short will quickly blow the fuse and keep the wire from melting down and starting a fire.

Here's a shot of where I placed that one (ahem) extra battery. On the right is a shot of the battery box in the trunk as it was when I first finished it. On the left you can see the extra battery pushed down in the gap at the end of the box. It worked out very well, and was easy to get into place and clamp down.

After I hooked them all up, I went through and took a voltage reading on all the batteries. After sitting for over two months, with 2/3's of the batteries sitting in a box and the rest still wired up in the car, they each read 3.29 volts. I suppose I had no reason to expect anything different, but I couldn't help being impressed. These really are great batteries.

I want to go through and re-verify and recheck all the connections for the high volt system and the 12 volt system before I replace all the fuses and throw the breaker. I should be able to get that done early tomorrow. There are still a few things I need to do after that and before it comes off the jack stands, so a Friday launch is looking unlikely. But that's OK, I should be back on the road next week. Can't wait to feel that EV grin again!

Wednesday, June 23, 2010

Apparently Late Night Math is Not My Strong Suit

Lots done today. Let's take a look at some of it.

This is the new location for the shunt. It's at the front right corner of the back battery rack. I had to cut and re-crimp a couple cables to get them the right length, but it worked out well.

Just to the left of that is the emergency breaker, or battery disconnect. I had thought that I'd mount it dead center on the back rack, but the cable for the positive feed to the contactor didn't reach the extra 2 inches. The symmetry in the engine bay will be off, which is kind of too bad.

Here's a shot of the new throttle assembly set up, installed and tested. It's difficult to make out what's what here, so I'll take another once the batteries are in. But you can see the cable anchor in the right side of the picture, and the pedal assembly just to the left of center.

And last we have a shot of the whole assembly mounted in place with the back row of batteries resting in their place as well. There's a bit more tie down work to do, then I can install the front row.

In addition to all that, I also got a few other things done. I re-installed the tray under the motor that holds the fan for the motor as well as the box that contains the new vacuum pump. I ran all the necessary power lines to the items and the vacuum line from the pump to the reservoir. I also installed the new cross brace that stiffens the chassis.

I don't think I mentioned it before, but the fellow that owned the car before me clearly ran it up on a curb or something. There was a bit of damage under the car, mostly cosmetic. However, the original cross brace took most of the abuse, and was a bit twisted. It still fit in place, but was very difficult to bolt in and was under stress once in place. The new one slipped on so easy, it was a pleasure bolting it on the car.

Which brings me to the odd title of this post. You may remember that I had 31 batteries up front in the original configuration. During the rework, I drew up multiple designs trying to get the cleanest install of all the batteries in as tidy a package as I could. Well one night, very late I came up with this design. It is the cleanest by far and I'm very pleased with it. There's just one nagging problem. There are 12 batteries in the front row, and then two rows of 9 in the back rack. In most worlds, that adds up to 30. Apparently for me, in the middle of the night, that sometimes equals 31.

For the life of me, I don't know why I never added them up again, but I didn't. (This is the part where you all laugh at me.) After standing and shaking my head in disbelief, I started laughing at myself. But eventually I started thinking about it objectively. This really was the cleanest design I'd come up with, and it's going to look great. I don't think I want to change it, or would have if I realized it at the time. There is room for one more battery in the trunk box. It will make the end of the box a bit cramped, and I'll have to redo some of the lines in there, but I think it's going to be worth it in the long run.

The worst thing is that it will delay my relaunch by a day or so.

Tuesday, June 22, 2010

Odds & Ends Part XIII

Lots to report today, but sadly no pictures. You'll just have to imagine how stunning the work is.

I finished the straps and mounting system that will hold the batteries in the rack that will be mounted over the motor. I still need to figure out how I'm going to get some brackets around the batteries to keep them compressed. I had it all worked out in my mind how I'd do it, but once I started working with the rack, I realized what I had in mind just won't work. Funny how that happens, you tend to not see in your mind's eye how different pieces will interfere with each other until you start assembly. Anyway, it shouldn't be to hard to sort it out, I'll just have to come up with something different.

Once I had all that done, I placed the rack in it's space so I could start figuring out how I was going to place some of the elements that have moved. I need to find new locations for the Link-10's shunt, the emergency disconnect, the bracket to hold the traction pack fuse and the anchor for the throttle cable. You may remember in a previous post I built the mount for the throttle pedal, but I hadn't built anything to hold the assembly that anchors the cable.

The shunt's new home was easy enough. It's going to be roughly in the same location it was, but I had to cut a small piece of angle aluminum to mount it to. Just out of dumb luck one of the new braces used to hold down the batteries was in the perfect spot to anchor the throttle cable. So that's sorted. Last I had to build a small bracket to hold the emergency disconnect switch on the front the new tray. I cut, drilled and had the whole thing mounted, and it looked great. Then I screwed on the big red knob that you slap to break the connection, and realized that I wouldn't be able to slap it down because it ran into the tray. I'm not sure if I'm just working too fast, or why I'm making such silly mistakes. Fortunately, it will be easy to fix that as well.

In addition I reconnected the lines to the reverse switch in the transmission. I really wish I had the proper connector to connect it up. I found the connector online and numerous places that sell it. It's about $4.00 or so, and it's made by Tyco. Would you believe every place that I could find it, it was out of stock, and had a lead time of at least 4 months. Apparently Tyco makes one batch a year and when they're gone, you wait.

I also ran an auxiliary 12 vdc line to the back of the car. This line is switched with the ignition. One of the things I found in the 2 months I was driving the car was that if the car sat idle for 24 hours, the 12 volt system would manage to drain about 1 kWh out of the traction pack. There are only a few things actually drawing power when the car is off, and they are drawing tiny amounts. The one thing that is on, however, are the DC to DC converters. They are providing 13.2 vdc to the car, as well as the SLI battery.

I know that you can leave a trickle charge on a lead acid battery forever, and it will always draw just a bit of power. I don't think they'll draw 1 kWh in 24 hours, but something is. I think it's either the DC to DC converters just using it up because they are inefficient, or the SLI battery is drawing it off. I'm just not sure, so I'm going to run some experiments. I'll disconnect each, one at a time, and watch what happens to the traction pack. When the SLI battery is disconnected, I'll look to see what happens to the traction pack and then I'll disconnect the DC to DC converters and see what happens to the SLI battery. If one of them is the culprit, and there appears to be no adverse affects to disconnecting it when the car is off, I'll use that new 12 vdc line to run a separate contactor that will disconnect the appropriate component when the car isn't running.

Lets see, what else is there to report. Oh, I also cut some plate aluminum to fit over the ends of the batteries in the front tray. This will make it easier to clamp them down and compress them. I still have to build that apparatus though.

Ok, that's it for today. Stay tuned because I'll have lots more to report tomorrow and I'll have some pictures up to show the progress.

Thursday, June 17, 2010

Front Battery Tray

Today I finished building out the front battery tray. Here's a shot of the assembly sitting on the garage floor.

Later, in the afternoon, I got the whole assembly mounted in the car.

That involved doing some minor, but time consuming work on the mount for the power steering pump. I had to keep it in the same position in the compartment relative to the steering rack. So even though the battery rack moved forward, and the pump had been attached to that rack before, I needed to keep the pump from moving along with it.

Now I just need to mount the back tray, secure the batteries to it, run all the interconnects, find a new location for the shunt and the emergency disconnect and then finish the mount for the throttle assembly. Then I can start checking all the wiring and start testing things. If all goes well, it will be out of the garage sometime next week.

Tuesday, June 15, 2010

New Battery Rack is Done

I didn't post much last week because I didn't work much last week. At least not on the car. 60 hours at work kind of steals all your time. And much of your will to live. But that's all behind us now and I'm back to working on the car!

The battery rack that will be mounted over the motor is done!

In this shot the part nearest the front of the picture will mount closest to the fire wall. I've placed a couple batteries in it so you can get a sense of scale. You might have noticed a slight rise in the cross beam the batteries rest on. There was no way to mount them straight across because the motor was in the way. Those cross members have a five centimeter rise from the edge to the center of the rack.

I also worked out the throttle assembly which is mount on the left side of the rack. Here's a shot of the left side.

I need to build some sort of enclosure for the throttle pedal to keep the dust and water off of it. On the opposite side, I need to mount the shunt for the Link-10 meter. That should be pretty easy, it should bolt straight to the new frame with out any problems.

I've built the rack big enough that I'll still have room to use some of the clamps that came with the batteries so compress them together, helping to prevent them from swelling (as one astute reader pointed out). I may need to address that issue for the batteries in the trunk box at some point as well.

Perhaps the best news is that I've realized I will be able to use the existing front battery tray the way it is, with only some minor modifications. When looking at my measurements of the space from before, I neglected to take into account that they included the white plastic boxes the batteries were originally mounted in. Well, I won't be using those boxes which means I gain 1/4 of an inch. Along with moving the front rack back by about an inch, I'll have about 1.25" between the top of the battery strap and the hood. In fact, I will be able to put the sound deadening cushion that was affixed to the bottom side of the hood back on, with room to spare.

But the best thing about that is that I don't have to re-figure and rebuild the brace that holds the power steering pump, which is suspended below that rack. I was at a loss for how I was going to handle that, but now I don't have to at all. It just means I'll be back on the road that much sooner.

Tuesday, June 8, 2010

New Battery Racks

Loyal readers will remember that I've decided to take this opportunity to redo the battery trays in the front of the car. Since I had to disassemble the entire front of the car anyway, I figured now was the time to do it. Of course I should mention why. Two reasons really.

First, I've come to find out that these batteries really are supposed to be mounted vertically. Originally, I'd read it didn't matter, and you could install them in any orientation you wanted except upside down. But since then, I've seen in multiple places that if you don't mount them vertically, the electrolyte will pool to one side of the battery, shortening the batteries life. Well, I thought the electrolyte was a paste, but I turned one on it's side the other day and could hear a faint but distinct gurgling coming from the battery.

Second, when going through the pack with a wrench trying to tighten the lugs on the batteries, I found it extremely difficult to get a wrench on some of them, and in fact, I couldn't reach 7 or 8 of them at all! That meant over time the constant heating and cooling of the terminal would cause the lug to work it's way loose (I already saw this on the lugs I could reach) eventually creating enough of a gap that there would be arcing and eventually fire. So, vertical it is!

Here is a shot of the work I did today. there will be more horizontal pieces running between the sides. Three to be exact. They will support two rows of 9 batteries just over the motor. That means I need to find room for 12 more. As it happens, the space just behind the radiator, and in front of motor is wide enough (by 4 mm) for 12 batteries. So they should all fit pretty well, plus I got rid of some steel that weighed quite a bit more than the aluminum.

I'm also taking this opportunity to replace the vacuum pump that I've come to despise so much. It is by far the loudest, most annoying thing on the car. I'd bought the pump off of eBay about a year ago for the bargain price of $110. It was one of the few parts I thought I could save money on because a vacuum pump is a vacuum pump. Right? Well it turns out there are pumps that are a lot quieter.

Here you see the original one on the left. It measured in at a wopping 74 dBA. The new pump on the right puts out a relatively quiet 58 dBA. The dB scale is logarithmic, and every 10 dB increase means that the sound you perceive is twice as loud. So this new pump will be roughly 1.6 times quieter than the old one. Was that worth the $300 I laid out for it? Well, let me throw this little bone into the mix. The old pump drew 8 amps, the new one, 2.5 amps. Now are you impressed? I thought so.

The old one still works great, it's just loud. I'll probably put it back on eBay.

Wednesday, June 2, 2010

WarP Drive is Engaged

Let me start out by saying that I debated long and hard with myself whether I should use such a nerdy title for this post. In one regard, it's beautifully elegant and accurate in it's description of the current situation. On the other hand, it betrays the fact that I am a big dork. But, when it comes down to it, you must be true to yourself, so dork it is!

The motor is back in the car! I spent yesterday afternoon bolting the adaptor plate, hub, flywheel, and clutch up to the motor. Today I mounted the transmission to the motor assembly and then, with my dad's help, lowered it into the car again. I desperately hope that I never have to remove it again. But if I do, at least I'm getting good at it.

I got the linkages for the shift knob connected, and everything seem absolutely great at this time. Once it was all bolted down, I took some of the cardboard templates I'd made while waiting for the motor's return and started placing them in the engine compartment trying to sort out battery layout. It's looking more an more like getting all 31 batteries up front and mounted vertically is going to be easier than I'd first thought.

There's no question that I have a lot to do, but I'm going to attack it pretty aggressively over the next few days. I don't really know how long before I'm back on the road. I'd hazard a guess of more than two weeks and less than 3, but we'll see.

Tuesday, June 1, 2010

The Return of the Motor

The FedEx truck pulled up moments ago, and that could mean only one thing. The WarP 11 has made it's way back home. Wouldn't you know it, the same malcontent that picked it up when it left, lumbered out of the cab to deliver it. Sadly, his mood hasn't changed. Fortunately his sour attitude can not dampen my spirits; the motor is back and I can start the assembly process!

I mentioned before that I'm going to redo the battery layout. I may need to redo a couple other things to get the fit right. Stay tuned for all the fun :)