Freitag, 3. Juni 2016

YEEHA !

We've made it (almost)


On May 20th at 14:30 the 2 hour long road worthiness test was conducted at the "Strassenverkehrsamt Zürich" (road traffic licensing department). Oh boy, I dreaded this moment. That's where all my efforts could have gone to waste. I feared that they'd find so many problems that I'd have to start over or give up. That's also why I involved the experts from the beginning, discussed my design and finally got a remark that if I'd follow the design, would not increase the power of the motor, not change anything in the chassis and keep all the security relevant systems running, I could get along with my conversion. But still I had so much doubt because the standards of road worthiness are extremely high in Switzerland (you folks in the US or AUS probably can't imagine). It was the sword of Damocles hanging over me during the last 3 years. But apparently all the worries were for nothing. I got a pass on all points except these three:
  1. With nobody in the car, the front weight is already at the current limit of 1180kg. With two persons in the car, it's 70kg over-weight. Darn, the conversion got 100kg heavier than I calculated.
  2. The brake disks - especially the rear ones - were rusty after 3 years not using them.
  3. The wheel alignment of the front wheels is off by 20mm on 1m - too much.
Nr. 2 and 3 are a piece of cake: Switch of regen for a while and have the alignment adjusted in a shop once the weight distribution is clear. But Nr. 1 is a bit a challenge. Either I have to move 50kg of batteries from front to back ("why only 50kg, you said 70kg ?"- yes, but mind the law of the lever) or I have to get a warranty from Volvo or a testing center that it's ok to go with a bit a higher load on the front axle.
Well, moving the batteries would be my last option because it'd mean a couple of days work again and giving up space in the trunk (which I was able to prevent until now). But there are other S80 models out there with higher load limits. One is the one with a V8 engine. It's got 120kg more on the front axle than my modell.. but except from maybe stronger springs, all the same parts are used. A confirmation from one of our two testing centers in Switzerland is just crazy costly: one charges fees starting at CHF 650.- and the other 3000.- for looking up their files and talking to the licensing department. Not an option! My hope now lies with Volvo. The homology provider of Volvo Switzerland contacted Volvo for a warranty confirmation that it'd be ok to go with 70-120kg more on the front axle. So please, please Volvo Europe/Worldwide/Sweden/Switzerland, provide me this 1-pager and your stamp on it !!!

I have to mention that the experts at the licensing department were really very friendly and supportive. I even got high praise that this was the most beautiful conversion of an electric car they've seen until now. I was dumbstruck by such a huge compliment from those who take the most detailed and professional look at the car. But albeit these issues exist, I was allowed to drive the car. I just have to fix them within a certain timeframe. 
My family accompanied me. My son (8 years) even got the afternoon off from school to be part of it. When we we were through with the test I was churning the fact of the overweight. But then suddenly it dawned on me:

I'm allowed to drive the car now!! I finally can drive the car (legally) !! I can use it for my daily commute - as of NOW !!

YEEEEEHA !! :)

Oh, we had a big family party on the way home - with monster ice-cream servings until everybody was full..  even the 4 year old gal :) When we passed a gas station I told them "Look folks, we don't have to stop there anymore." and after the next turn there was a barn with a huge photo-voltaic installation on the roof and I said "From now on, that's our gas station !".

The most touching thing about this whole story is how proud my son is of me. He keeps telling everybody, explains at school what I've done - and you see it in his eyes when he looks at me. I most likely don't get the full grasp of the impact it has on him. I'm not the type who's terribly proud of what I achieved with the conversion but what I'm really, really proud of is that I was able to show him that it's worth to stick to something. Even if it takes 3 years, you can reach a goal and change the world a bit. I have a feeling that this might be one of the biggest lessons I was able to teach him.

Wrap Up !


Let's wrap-up things, shall we?

Since the last post, I've invested a lot of time to get the car street worthy - honestly, I've had enough of tinkering and toying around. I wanted it on the street, I wanted to use it in my daily commute. In this post I'll collect all loose ends which I did not report about yet up to a stage where I dared to address the testing center and book a date for a (first) inspection.

Batteries again

Well, the front battery box was installed, the carriage for the batteries under the car as well and I even installed a crate for the batteries in the trunk. All well. But what about water, dirt, debris and salt spraying up from the street? How to protect these poor cell terminals from corrosion? Well, I had a plan from the beginning but with the help from Matthias from www.fahrzeugausbau.ch it got even better: I wanted to add a PE (Poly Ethylene) plate as main shield and just fill all gaps with construction foam - you know, this yellow sticky mass which extends by a factor of 3 or more. Matthias suggested to also use PE foam. He provided me with a load of cut-offs from his construction work and man, did it come in handy! Not only was I able to easily secure the cells in the construction, but I also filled up the major holes. So I had to use less construction foam instead . Well, I still used 4 bottles - but mainly due to my unprofessional handling.
The PE plate was also fabricated by Matthias and together we created an attachment system to hold the plate in place. The plate is 6mm thick and is able to hold of 9mm bullets. So we have enough protection from stones and debris. I wonder if Tesla's shield would hold up against a 9mm bullet :)
I know the yellow construction foam looks scary and ugly at first. But once you cut it down with a knife to the right proportions and paint it black with bitumen spray, it just vanishes. And together with the PE foam I was very cautious not to miss any spot and get all gaps filled water-tight. Well, at least spray water-tight :) (see last three pictures)

Cabling

Some impressions from my HV cabling. The first picture is probably the most noteworthy and it's also provided in a higher resolution so you get a glimpse on how the HV distribution was created. On the left side you see the red distribution bars for HV+ and on the right the black copper bars for HV-. Between the red ones you see two contactors. The left one's the secondary HV contactor. It closes after the HV contactor in the trunk did engage and the pre-charge cycle is completed. The right one will be used for fast charging via Chademo in the future. In the middle you see an HV relay which connects the green resistor for pre-charging. And on the lower right you see the shunt for coulomb metering (AH). The HV box is mapped pretty much 1:1 in the control diagram.

EHPAS Pump

This beast is a bit the bad boy in the car. In emergency mode (no CAN control messages) it's power is barely enough to keep the electro hydraulic power assisted steering running for my heavy S80 - but more annoying is the humming noise it creates. Even packed into foam rubber and covered by the front bumper, it creates too much noise for my taste. I started thinking about using the emergency brake switch connected to GEVCU to switch off the pump - so it'd be more quiet in a traffic jam. But with some music it's ok. (I'm oversensitive, I know.. it's just that the pump destroyed my fantasy of an absolutely quiet car).
But the worst thing is that although I bought this pump via an official retailer, I get absolutely no support. Not even a CAN matrix or guide.. or just even a CAN ID. Same old song from the manufacturer TRW : no support for non-OEM's... #@&##@ !!!
I could live with the first two draw-backs but the third one brings me to the point where I'd definitely not recommend this pump. Shame on you TRW - you're actually the only player in the whole game who gave absolutely no support for your 600.- pump.

GEVCU Extension

The GEVCU is a great piece of hard- and software. Especially with the WiFi chip and the web-interface Charles Galpin and I created for configuration and monitoring.. I just love it and people freak out when they see it displaying 10 values with gauges in real-time. But it has some drawbacks:
  1. Not enough digital output ports (8 are not enough for my conversion)
  2. The MOSFET's are not intended to handle the big inrush current when closing a HV contactor
  3. It lacks some inputs e.g. for single wire temperature sensors or pulsed flow meters. 
  4. It has no SW-CAN (single wire) bus to communicate with the Eberspächer heater
To resolve this issue, I created a GEVCU Extension board and software based on GEVCU's code. It's based on a 16-channel 220V relay board you can order for under $20.- on ebay, an Arduino Due and a self-made shield which holds a CAN tranciever, a SW-CAN transceiver and an EEPROM to store config values like GEVCU.
GEVCU communicates via CAN bus with the extension board and tells it to engage the pre-charge relay, the contactors, start the heater or coolant pump and fan. And in return for that, the GEVCU extension board reads temperature and water flow measurements and reports them back to GEVCU via CAN also. There are also some safety features built in so should the two boards get out-of-synch, the HV contactors will be released or not closed at all (state machine on both boards).
I also created one last video before hitting the road from some old dusty recordings.

Charger connector


The only place the connector for charging should go is of course where you used to hook up the gas nozzle. A friendly fellow by the name of Andre Te Sla (no joke !) runs the company www.electroscout.ch. He was able to provide me with a receptacle which fit in perfectly and also a 1-phase charging cable that I can hook up to the car and a red CEE-16 plug. I created myself some adapters for CEE-32 and Swiss household sockets. Works like a charm. All that's missing, is the 880 Ohm resistor between ground and a 12V PWM signal provided by official charging stations so the signal goes down to 6V and the charging process starts. But until now I was happy with dumb 230V sockets.





Dienstag, 2. Februar 2016

Device Plate - and a lot more

Battery Box - Black Box

After mounting the battery box it was time to fill it up. As mentioned in the latest post, it was filled with two levels of batteries. Yeah, I know, it's going to be hell to maintain the batteries and check for problems. But heck, that's a consistent design flaw in my conversion. Also the batteries on the bottom of the car are only reachable if I remove them starting from the rear end. Talking of these batteries on the bottom: to give them extra protection against moisture and salt water, I intend to spray the terminals with PlastiDip. This should help to prevent corrosion and is easily removable should the need arise.
Aside from loading the battery box, I also mounted an external box (grey) to hold another HV fuse. Not knowing what exactly happens when such a fuse blows, I think it's a good idea to keep them well separated from the batteries - outside of the box (still some lingering impressions from the short circuit).
The black wire you see attached with hot glue in the battery box is the wire from a temperature sensor. The sensor was glued inbetween 4 cells. It's used to ensure that the batteries are not charged below freezing point and to detect a run-away situation during use or charge. I know it's crude - but I don't like too many wires dangling around the cells and calling for other trouble.
The top level of cells had to be added row by row and pushed under the already welded on cover. The cover had to be welded on because it will go under the front cover and can't be removed anyway. The grey block you see on some pictures is a sanding block for PCB's - to get polished copper which easily accepts soldering tin. I got it from www.conrad.ch. In my opinion it's perfect to create a clean and shiny surface on the battery poles and straps. It creates some dust which can be easily removed with a handheld vacuum cleaner - no issue.
The battery box in the back is currently made out of wood aas a prototype. Here we need to bend some metal so the batteries will fit in to the spare tire compartment and use up no space at all in the trunk. I'm pretty proud that until now the only change to the structure of the car was made in the spare tire compartment. There I had to drill the only holes. Otherwise no change on the car structure was made - no hole drilled, nothing. I mounted all parts on the vanilla structure, used only existing mounting points and through holes. Cool, eh ? :)

Device Plate - Aluminum Sandwich

First I created a prototype out of an MDF plate. It was very useful because I drilled a lot of unnecessary holes and was able to experiment with the setup. It also helped getting all the details worked out at the rear of the plate, where the car - once again - shows no straight lines. Based on this template, www.fahrzeugsausbau.ch created a final plate out of an aluminum / PE sandwich plate very easily. It's very robust (unbreakable ?) and lighter than a pure aluminum plate - a good choice. The plate resides on 3 angles attached to the firewall (created out of an L-profile) and on the front on a lid which was welded earlier to the battery box. Even fully loaded with all the devices and thanks to routing the wires and cables at the back of the plate, I'm now able to lift the plate about 20cm at the front and get access to all the stuff below it. On the underside there was also enough space to mount the 6kW heater from a wrecked Chevy Volt.

EHPS pump - Powerful but noisy

With the help of www.klaus-ag.ch we also got the electro hydraulic power steering pump hooked up to the original hydraulic system. It required three high pressure connections. With some makeshift (oh no, not again !) electric connections to a 12V battery, I got it running, lowered the car to the ground and kept steering happily from left to right for about 10 minutes - like a child. Don't worry, the tires are to be replaced anyway - but I left two black marks on the floor - whoops :)
A quick visit to a junkyard revealed the necessary connectors for the pump so a professional installation can be made. It's interesting, the pump has an 80 Amps fuse but only 10sqmm cables (7 AWG) where all tables state for 80 Amps you'd require 16sqmm cables. Well, normal load on the pump is way below 40 Amps and I hope the guys at Volvo know that a short on a 10sqmm cable is able to blow a 80Amps fuse before melting down.
Although I bought a new one, it's well worth looking for an electric power steering pump on the junkyard. Volvo V50's and V40's after 2008 tend to have one. Make sure you get them with mounting brackets and plugs. Two things I have to say about the pump: 1) It's a bit noisy.. I hope with some rubber foam, I'll be able to make it more quiet. Otherwise the "silent e-car" will not become reality. 2) The folks at TWR suck ! It took me about 10 calls to reach the technical responsible only to be told off quiet harshly that they don't provide support for car shops. Only car manufacturers. They won't even give out a CAN matrix - for their product which I bought through official channels. Shame on you TWR !

Fuse Box - Finalization of 12V connections


To finally clean up this mess of cables you see on the left side of the car (right on the picture), I also straightend the 12V system out. Cables were shortened and connected properly to the car's 12V supply line with 50sqmm butt connectors. To hook up the auxiliary 12V battery (remember ? a tiny 9Ah motor cycle lead acid battery), I spotted an empty space in the high-amp fuse area of the engine bay fuse box (red arrow). It's always on 12V - unswitched. I installed a 50amps fuse there. Also to get the constant 12V for the contactors and other EV stuff, I located an unused place for mini fuses which has 12V without ignition on. that's what I need to be able to activate the contactors when charging.
There's another free place for a similar fuse which I'm going to use for the EHPS pump. I'll try a 70 Amps at first to be on the safe side.

Cooling Loop - Angles and Air

Another thing that had to be re-done was the cooling loop. Before I just forced the hoses and they got wrinkled reducing water flow. I used 90 degree angles to get the hoses straight and prevent damage. One important change to the system is the integration of the expansion tank. Before it was hooked up with one hose only so air bubble could travel up the hose and water flow down passively. This caused a lot of effort to vent all the hoses and I had to play with the Bosch water pump a lot - which doesn't like air at all. Now in the new setup I use the two small overflow return connectors to pump the water into the tank. Due to some walls, no air should get to the outlet on the bottom. The pump is attached right after the expansion tank so once it's filled with water, no more air should reach the pump and the system will rid itself from air automatically. The only thing missing here is the radiator - here I just can't make up my mind and at the beginning I'll just use the long hose to dissipate heat in the air flow. But this won't work in summer or when driving uphills.
I use water flow sensors to monitor the flow of the coolant and especially of the water passing the heater. If not enough water passes the heater, it will be disabled immediately to prevent expanding steam destroy anything. The maximum flow rate I get at the moment is 5 liters/min. For a pump rated at 15 liters/min it's a bit low suggesting some resistance in the loop. I hope it's because of air which might still be present in some hoses with a steep angle. When driving over a couple of bumps and curves, I expect the air to vanish because from the shaking little bubbles should find their way out.

ABS - finally some snow !

The day we had enough snow on the roads, I took the car out for a quick spin. I wanted to find out for a long time now if the anti-block-system works eventhough the ECU thinks the motor is not running (anymore). It's an absolute requirement to get the car street legal. So I was a bit anyious about it. Would I first have to fake engine signals to get the ECU running or would it work without? So I accelerated to 20kph and hit the brakes... and.. the familiar krrrrrchhchchch started - a clear sign that the ABS was working. Cool !!! :) Let's also test the anti-spin functionality by pushing down the throttle a bit harder and even here: the brake was automatically applied to the spinning wheel and the throttle was reduced. Very nice ! Well done Bosch and Volvo ! :) Me happy !

Summary - All good things come to an end

After installing some more cable protectors and the 6 temperature sensors in the battery bay/boxes, I'm re-adding the car body parts and it's really really coming to a point where I can think about getting the car street legal again. Some covers on the floor to protect the batteries from salt water, some construction foam to seal off the more complicated areas and to hold the batteries in place.. and we're good to go. Even if I'm required to have a working heater, I could get that up and running in a breeze: the code is ready, the heater installed, the pump is available... only a couple of hoses, a connector for the pump and an expansion tank are missing... compared to the rest: peanuts ! :)
It's funny, you might think "finally" - me too of course - but in the recent weeks, I was just in a mode "get into it and work late on the car during the week". It hit me once late at night that it's coming to an end while I was looking for things to work on. From rear to front, it was hard to make out anything. All cables are securely attached, everything is getting nice and tidy.. it's really surprising when you're in some kind of routine to realize it's about to change. :)