I’ve gotten the computer installed and working. It does some very simple processing, that (to be honest) should have been handled by the motor controller.
The embedded computer measures the outside temperature of the motor, and then turns the motor fan on or off, and changes the power level of the motor controller.
Simple stuff, really. I’m sure *someone* could have done it entirely in hardware, but being a computer programmer from years back, this was a better way for me to go.
I’ve replaced all but the headlights with LEDs and seen a dramatic decrease in current during their usage. What was interesting is that I did not have to replace the blinker relay (apparently you need to on newer cars). I got the LEDs from www.superbrightleds.com.
I’ve also made regen a normal part of driving, so I’ll need to put back the circuit that lights up the brake lights when regen is active. The reason for this is to make shifting easier – when regen is active the motor quickly drops from high RPMs to almost zero within a second or two.
So I’ve done another set of calculations, and I’m getting 350wh/mile driving to and from work. Most of this is freeway driving with some stop-n-go.
Wow, what a lot of work. I have 108 batteries (the 109th doesn’t fit due to slight miscalculation…shrug), which means I have 216 bolts to fit in, 108 sensors to attach, etc. Next step is to test out the BMS to make sure it can handle the job properly. Fortunately, Elithion does a stellar job on their website, so I know what to do next.
Here is the front battery packs all wired up.
And here is the rear battery pack all wired up (my figures hurt now).
In order for the Battery Monitoring System (BMS) to monitor all the batteries, there has to be some sort of device that attaches between each post on each battery. For the Elithion BMS, there are banks of these monitors and they all report to the BMS itself. It’s a bit complicated. Fortunately, the Elithion website has some very good hints on how to go about this. In the picture below, I have one bank connected up, with two more to go in that bay.
So for the past few days, I’ve been making a super effort to clean up the battery boxes, and surrounding area. This means putting the trunk lids back on, vacuuming up all the odd pieces of metal, and taping off all the exposed metal that could be hazardous in the battery boxes.
Then I went and lifted all the batteries into the boxes and put shims in around them to stabilize the batteries. Well, shims, pieces of wood, spare plastic tubing, whatever works and is generally non-conductive.
Here’s the rear trunk:
And here’s the front trunk:
Next step is to start wiring all the batteries (109 of ‘em) together.
Long weekends were made for working on cars, especially when turning them into real electric cars! This weekend was no exception. I finished up all the battery communication cables and hooked them up to the BMS. I also added in the battery disconnect to the rear trunk (with some necessary re-arrangement of the cables). Next up is adding in the control wires between BMS, Motor Controller and Charger.
I also took the opportunity of adding in the rear trunk shocks and replaced the rear trunk lid – really nice to have the lid back in place. Still a bit of cleanup near the shocks, but really nice items from camp914.
The new guages are installed – one is for the pack voltage, the other is the pack current. Both are left and above the dash. Speedo is also reinstalled, so the passenger compartment is (mostly) done.
Working on the BMS battery connectors now. A lot of fiddly little parts that require a magnifying glass (for my somewhat older eyes) and a good soldering iron. Elithion did a very good job with their battery connectors – they actually show the color of wire to hook up where. On the end of each battery group there is a connector that will have two wires attached – either black/red or green/white. If you look carefully at the two wire connector on their part, it says B R / G W (or something like that). Nice job. 
I still have the rear battery pack to work on, and then it is time to fuss once again in the rear trunk – I now have a quick disconnect for the battery pack that I need to fit in.
I finally figured out which of the interconnects are which. This took some careful reading of the Elithion website (my fault, not theirs) and as a public service present to you which connector is which:
I’ve gotten the current sensor put together, but these tiny wires are enough to drive an older guy crazy. I had to go and buy one of those soldering stations with those clips and the magnifying glass. Sheesh.
The holidaze were great – warm weather, no stressful driving anywhere, and time to take care of the small details. Cutting the boxes to proper size, attaching the fans to the boxes, running BMS signal cables (which involved pulling and re-running the power cables through the driver-side tube) and so on. Ready to start putting batteries in and hooking up the BMS cables. Oh and mounting the BMS with a power supply as well. LOTS of small stuff.
I’ve had a busy weekend adding in the plug and getting the wiring set up. The plug is an interesting model – it will automatically eject the plug when the key is turned – very nice feature.
The AC is routed to the relay panel, the charger and to the EKM meter. The EKM meter has a ring around the live wire to the charger so it can record how much power the charger is using.
Rear Trunk with AC lines
Here’s a picture of the new plug.
AC Plug installed
Well, nuts. The new charger won’t fit into the front trunk, so it will be installed in the rear comparment, along with the new DC-DC converter. I’m also putting the aux battery in the rear compartment.
Net result: no need for relays in the front compartment or engine compartment. I’m creating a new relay panel that will go in the rear trunk, and will move the DC shunt to the mid compartment (nearest the amp meter). Lots of rewiring, and re-organizing, and most likely a new set of connectors in the engine compartment.
I’ll post pictures once the relay panel is installed.
Sean came over and did 3 hours of hard work under the car while I “helped” by handing him tools and making bad jokes (as if I make any other kind). He replaced the springs and torsion bars, but kept the shocks (as the shocks are very good autocross shocks).
It was a good thing he was looking under the transmission, as the speedo and clutch cables are both “toast”. He’ll be getting me some new ones later this week.
Safety tip: ALWAYS have an expert replace your springs, those things can kill you if you are not careful.
So while I am waiting for the new speedo and clutch cable, I will continue working on the wiring in the front compartment. Lots of fiddly wires and not-so-great documentation. *shrug*
After dealing with another long trip (Macau, PRC) and the flu (caught before the trip, and made worse by the travel), I’ve finally done a bit more work. I’ve got the power cables hooked up to the controller. For some reason, the power cables from the motor are REALLY long (another cleanup project later).
Power cables going to controller
I’m a bit worried about the cables going through the floor of the trunk – those grommets are not very strong, and it is possible for the metal to cut through the rubber and short out the cables. Yet Another Cleanup Project.
Power cables through trunk floor
Some minor pounding created enough clearance for the rear rack to snugly fit into the engine compartment. Following another 914 conversion, I cut out the rubber inside the passenger compartment and drilled out the holes as I went. MUCH easier than trying to get all the holes done right the first time. I also got a lot more POR-15 for the exposed metal (during the various pounding episodes). This is starting to look like a real electric car!
Rear support plates inside the passenger compartment
Rear battery rack attached to passenger compartment
Wiring is up next.
Oh my, I feel like a pale John Henry. Making space for the middle battery rack required a LOT of pounding of metal. Sean wanted to cut the metal, and then weld it, but I was worried about the heat on the steering column. So for the past two weeks, I’ve taken to going out to the car, pounding on the metal for 1/2 hour and then retreating to the house. I *think* I’ve won today, though. I do have some concern about the height of the box, but that’s for later worries.
Where the middle battery rack will go
Middle battery rack set in place
Electro Auto was extremely prompt in sending the missing rear battery rack support posts. I was VERY happy with that level of service. However, not all is fine with the rear rack. It doesn’t fit (of course). I need to pound some metal in the engine compartment as well, but I’m worried about structural strength. I’ll know more after talking to Sean.
Rear battery rack support post
The black pen marking on the yellow metal above the post is where the rear rack is being held up.
In order to keep things moving at the usual snail’s pace, I picked up a flu on my last business trip. This kept me from visiting relatives in Santa Clara, and from doing anything on the car. However, once the flu left, I decided to install the remaining racks (rear and middle). As always, a few small problems were discovered: no supports for the rear battery rack, and the middle rack angle brackets are too short. I guess I gotta do some metal work now.
Rear battery rack and new relay board
The rear rack is not mounted yet, just sitting in the compartment – the fit was too tight to remove it (oops). The space below that hose is where the support mount is supposed to go. Also, I got tired of the relays being attached to the metal, and after reading some posts about possible arcing across that fuse, I put this ABS plastic board inbetween. Makes for easier mounting, too.
Middle battery rack - with metal that is too short
This is just frustrating, but nothing serious. I can cut new angle bars, paint them with POR-15, and then install. I still have to pound out the body so the plastic battery box can fit into that small space, though (later).
[UPDATE] Electro Auto shipped the rear posts today, and will be shipping the wiring diagram later on. Looks like EA is back in business (yay!)
Wow, finally got the engine mated to the transmission and mounted to the car. I got the axles hooked up after the pictures were taken. This is starting to look like a real car again!
Wow, now that the trunk is all nicely sprayed and looking (mostly) well maintained, I installed the front battery rack. This was actually a very simple thing to do – 8 holes, two “bar-bolts”, 4 bolts, 4 washers and 8 nuts. The “bar-bolts” are actually two bolts welded to a bar – so the name actually makes sense.
Front Battery Rack Installed
Well, nothing like 3 funerals and a standards meeting to throw one off their stride. (Sounds like a bad british sitcom, doesn’t it?)
However, I have been busy on the car for the last few days. For example, I have attached the flywheel to the motor – this involves attaching a hub to the motor and then the flywheel to the hub – all within a tight tolerance.
And at the same time, I’ve been working with Sean to get the front trunk repaired. Sean found a donor car for some metal, and cut that donor piece out and then welded that piece into the trunk. Now I get to grind the metal, seal the seams, smooth everything out and then paint.
Wow, I bet you thought I had given up. Well, no, work related travel (Prague, compleate with excellent beer), house stuff (replacing the pump in the pond, and mortaring some rocks), and family (funerals are never fun, especially when you have the ‘honor’ of doing the Eulogy).
In any case, I got the terminal blocks installed and some of the wiring hooked up. Naturally the kit didn’t have the right terminal blocks, so I got some other blocks. And the other blocks use the closed connectors (unlike the spade connectors that the kit uses). *sigh* So I am using different terminal blocks and connectors. It’s such fun.
