Would I do it again?

Posted April 29, 2013 by rhamje
Categories: Uncategorized

It has been quite a while since I completed this project. While the Fastback is running just fine, I am sometimes asked if I would do a project like this again.  The short answer is “No”.

Last summer I took an opportunity to buy a new Think City EV for a great price.  It is a wonderful little car.  And when I consider all the other options like the Nissan Leaf and Smart Electric, I have come to believe that the days of the hobbyist EV conversion are numbered.  Here is my comparison of a new EV versus converting an older car to electric drive:

NEW CAR advantages:

1. Lower cost than conversion (now 50% less in some cases)

2. Financing available

3. Latest safety features

4. Warranty, and dealer service

5. No “old car” issues like body rust, failing parts, etc. I’ve personally had almost none of this, but it could happen any time.

6. Resale market

7. More usable space, greater overall utility

8. Instant gratificaiton – write a check today and drive it today

CONVERSION advantages:

1. Lower environmental impact (re-use)

2. Finished product is unique

3. If you start with a cool old car, you have an even cooler EV

4. Learning opportunity

Since I started my project, the market has changed dramatically.  There are many choices in new EV’s now and the price continues to fall.  Meanwhile, the hobbyist market has not seen comparable price declines.  The batteries, motors, controllers and BMS’s that are available to a home builder have not changed much in features or cost. Nor do I expect this to change – the big manufacturers have the economies of scale that no hobbyist can match.

The bottom line?  If you are looking for a quality EV for transportation, go to your local Nissan or Smart or Mitsubishi or Ford dealer.  If you are want to make a statement or take on a challenge, and have the money to spend and patience to match, then a conversion still makes sense. Essentially, the EV conversion now resembles the ICE kit car – a labor of love undertaken by few.

When I started my project, there was no mid-market “store-bought” EV option.  The few available were either crap (think Zap Xebra) or six-figure expensive (Tesla Roadster). How much has changed!

First maintenance

Posted November 16, 2011 by rhamje
Categories: The Project Log

This week I had to perform the first maintenance on the Fastback in more than a year of driving. The shifter linkage separated from the transmission, leaving me unable to put the car in gear. The car had to be towed, but the repair was quickly done by Scott Rife of Rife Motors (the best VW man in Portland!).

I wasn’t too happy being stranded and stuck with a towing bill. But it was gratifying to realize that the first work of any kind in a year was unrelated to the conversion itself. Still no repairs on the electrical bits, so everything is holding together well.

Heat!

Posted November 30, 2010 by rhamje
Categories: The Project Log

This past weekend I installed a 1500 watt heater in the Fastback.  Last night we tried it out on a rainy night and it worked great!  Instant heat.  I’ve got it plumbed into the defroster ducts at the moment, since seeing where you’re going is a priority.  I may later add some ducting so it will warm the passengers as well.

In most EV conversions, the heater core is replaced with a ceramic heating element and everything else is left stock.  Since older VW’s don’t have heater cores, a complete heater is needed.  Fortunately, Canadian EV offers just such a thing and they are a great company to do business with.  Here is a photo of the installed unit.

Heater installed

The black box with “240” written on it is the heater itself, with a fan housing below it.  You can see one of the two ducts on the right, going to the defroster tube.  There is a contactor behind that tube – this is a switch that turns on the 288 volt power supply when the heater switch is flipped.  By using a contactor wired into the heater fan switch, there is no risk of creating heat without air movement, which could cause a fire.  The orange, yellow and red wires are for the various fan speeds – they go to the dashboard switch.

The entire unit is mounted to the front cab wall beneath the dash.  In the Fastback, this spot is occupied by a fresh air blower which I removed.  The fresh air inlet is now covered with a piece of ABS plastic which I cut to match the profile of the removed blower housing.  A rubber seal is caulked in place to prevent any water from getting in.  It all works fine – we’ve had a lot of rain lately and everything is dry.

The heater is controlled with one switch which I mounted in a hole where the fresh air controls once sat.

Dash with Heater Switch

The entire job took about four hours, including removing the fresh air blower.

My conversion project is essentially done.  There is still some BMS work needed, but I have been able to successfully charge and balance the batteries without the BMS.  I still want to get it working right, but at least the car is a reliable all-weather driver now.

 

Finishing touches

Posted September 5, 2010 by rhamje
Categories: The Project Log

This weekend I finished up the last remaining battery box.  No more battery work (yeah!).  All 30 cells in the front pack now report to the BMS and have a full charge.  This took about four hours of work.

Three of the batteries in the front pack were dead and had to be replaced.  This meant removing the battery box which was pretty simple.  Two of the dead cells were at the end of a row, so it was easy to tap the whole row out, replace the two bad ones and tap all three back in as a block.  The other end with one bad cell wasn’t so simple.  As I was pounding it out, the casing cracked and the fluid leaked out.  Fortunately, LiFePO4 batteries aren’t particularly poisonous and don’t contain acid, and the actual lithium package inside did not leak.  Once the pack was complete, I then had to wire and test the BMS boards.  Twenty-six had been working already, so it was fairly straightforward to insert four more.  Everything worked!

Last step was to fabricate the plastic cover and then re-insert the battery box.  This proved to be fairly awkward, but I did finally get it done.  Here is how the finished product looks:

Front Box with Cover

Next thing to do was fix the rattling shifter.  The rattle was caused by a $3 plastic bushing on the shift rod that was broken in half.  This let the metal shift rod bang against the metal guide, making quite a racket.  It took me almost five hours of incredibly dirty and frustrating work to remove the shifter, take off the broken bushing, replace it, and re-install the shift rod.  VW mechanics sure earn their money if they have to do this job often!

This morning, I reconnected everything and we drove off with a full charge on 90 working batteries, and a nice quiet shifter!

Two things remain and the car will be 100% finished: BMS troubleshooting (one of the rear banks is reporting a fault) and installing a heater.  I can also mess around trying to make a Bluetooth connection from the BMS to my Droid phone – but that’s just for grins.  So close…

Another Expensive Education

Posted August 29, 2010 by rhamje
Categories: The Project Log

Yesterday, I learned more precisely how much range the Fastback has.  We had to take a no-notice trip to Beaverton, about 12 miles including a big uphill section.  Halfway up the hill, the controller went into “limp-home” mode and our speed dropped to about 20 mph.  A brief stop allowed the batteries to recover a little and we made it to our destination.  At that point, the car had been driven 72 miles, about half of it freeway driving, and there was essentially nothing left.  So – it’s official that the Fastback has a range of 72 miles with a mix of freeway, hill climbing and around-town driving.  I am pretty certain that it will do 100 miles+ of in-town driving.  This isn’t too bad really – the Nissan Leaf has similar capability and the Chevy Volt about half that.  It’s also better than my original expectation when I started the conversion.

My plan was to recharge in Beaverton for the drive home.  I was more than a little miffed to arrive at the much-ballyhooed charging station in downtown Beaverton, only to find that it is shut off!  So I then tried a battery store and two car dealers, but none of them had a 20 amp 115VAC outlet.  In the end, I had to call a tow truck, which took over three hours to arrive.  Not my favorite day last week.

The Beaverton charging station is on the street between the library and the farmer’s market.  It has a reserved parking space for electric cars to charge, which of course was occupied by an SUV when I arrived.  An angry-looking woman eventually got in the SUV and drove off – she struck me as the type who is always angry-looking, but maybe that was my bias.  In any case, I then parked and discovered that the station is shut off.  While I was pondering what to do, an old guy on a scooter came by and bitched at me that if the city was providing free electricity for me, they should give him free gas.  I explained that #1, the city wasn’t providing anything for me at that moment, and #2, the electric box has a credit-card swiper on it so is presumably not free, and #3, the box is operated by a private company (based in Beaverton), not by the city which had only provided a place for it.  He was unconvinced, but I sure felt unwelcome.  I once lived in Beaverton; it’s almost embarrassing when the residents are so obnoxious and ignorant.  There was one high point – the SUV got ticketed for illegal parking.

Enough ranting. The Fastback was towed home without incident and the batteries do not appear to have been damaged by discharging.  The controller has logic in it to prevent total battery discharge, and it works.   So that test has been passed.  In the future, I will try to keep a full charge on the pack all the time; going 25 on the freeway and being towed home is no fun.

Buttoning Up

Posted July 25, 2010 by rhamje
Categories: The Project Log

This past week I completed the rear portion of the Fastback.  The BMS is fully functional for the back 60 batteries and the battery covers are  installed.  All that remains is replacing three dead cells in the front bank and installing that cover.  Then the project will be finished!  Except for a heater.

I took photos of the finished portions so you can see how it looks in the end.  First, the wiring under the back seat:

Wiring under back seat - driver's side

This rat’s nest is wiring for the BMS and control relays.  It actually looks a lot nicer now than a few days ago, as I coiled and tied down everything.  In the center is the BMS controller with 12 wires to the battery banks and one wire to the current detector, plus six wires for control (2 power, 2 ground, 1 for charger shutoff and 1 for motor shutoff).  At the top, bottom and right sides are the control relays.  These include two original relays for turn signals and brake lights, plus six others for the EV function (2 for charger interlock to prevent driving with the car plugged in, 1 for the key switch which starts everything when you turn the key, 1 for regeneration which turns the brake lights on while regenerating even without using the brakes, 1 for BMS charger interlock and 1 for BMS motor controller interface which turns the motor off if the batteries are being over-discharged).

Back seat wiring - passenger side

The other wiring is under the passenger side, shown above.  Here we have the small 12 volt battery to the left and the current detector to the right h(ard to see – sorry).  At the bottom is the DC/DC converter.  Not visible is a small relay for which kicks up the DC output to 14.3 volts when driving so the headlights don’t get dim.  To the upper right is a white bar – this is the 12 volt distribution block.  In both pictures you can see wiring coming through the original heater ducts, and maybe you can make out the foam I sprayed in there to seal it up.  This cut down the road noise dramatically.  The foam is standard window insulation, but the type that won’t make toxic fumes if burned (DAP Tex-Plus).

Engine Compartment - Driver's Side

Here is the motor, controller and rear-most battery bank, with a cover on it.  The red block is the service disconnect mentioned in an earlier posting.  The throttle cable and spring are visible to the right of the controller.

Engine Compartment - Passenger Side

The right-hand upper battery bank contains 18 batteries.  There is now a plastic cover over it to protect against dropped tools, etc.  To the right is the rear-most bank with its cover.  This bank has six batteries.  Two of them died due to bad wiring of the BMS.  I could not remove them, so simply added two more batteries and wired around the dead ones.  Better to carry around an extra 11 pounds of dead weight than spend 8+ hours dismantling the car to get them out.  The two replacements are laying on their side with the terminals facing away.  It turned out to be pretty simple to get them in there and wired.  LiFePO4 batteries can be mounted in any orientation, which made this possible.

Lower Battery Box - Passenger Side

Lower Battery Box - Driver's Side

Motor Mount and Transaxle

The three pictures above show the underside of the rear-end as finally installed.

One more battery box to go and it’s done!  On the cost front, I have spent another $1,550 buying replacement boards for the BMS and cells that the BMS destroyed.  And another $100 for professional assistance with the last wiring issues.  This brings the total for the EV portion to almost exactly $30,000 before tax credits.

Public Debut…and more lessons learned

Posted July 13, 2010 by rhamje
Categories: The Project Log

On Saturday, July 10 was the Portland EV Awareness Day at Pioneer Square in the heart of Portland.  I took the Fastback and showed it to the world.  There were lots of cool cars to see, but still many people stopped and asked about our car.  One of the OEVA (Oregon Electric Vehicle Association) members took a bunch of pictures: http://www.flickr.com/photos/darkstarpdx/sets/72157624467961958/.  It was a hot sunny day and I wish I’d worn sunscreen and a hat…

I cleaned the car really carefully (with a toothbrush in spots) and put a nice wax on it so it would look pretty.  Jeanette came by and took some pictures.

At the OEVA Show

At the OEVA Show

I also got to take a close look at the other conversion that people had done, and talk to them about their experiences.  I learned a few things about how to properly mount batteries, and other sources for parts and systems.

My design for the battery boxes has a few flaws.  If you are considering a conversion, please think hard about access to the components after installation.  In my case, I should have done two major things differently.

Mount the batteries on shelves, not in boxes.  The batteries come with clamps for locking them into compressed blocks.  I tossed these and put the batteries into boxes instead.  In hindsight, this was dumb because: (1) it’s very hard to get a single battery out; (2) it forces you to do your battery wiring with the batteries in the boxes; and (3) the boxes are heavy.  What I should have done was use shelves with a 1″ lip.  I then could have bound the batteries into blocks of four or five and simply dropped them onto the shelves once they were wired.  A simple hold-down bracket would complete the job.

Use a modular design. In the upper rear engine compartment, my design has one big box/shelf combination that holds 24 batteries and the controller.  I should have designed this as three smaller units.  Having it in one piece caused two big issues: (1) I cannot work on a drive-train component such as the clutch or transmission without removing the entire rear setup; (2) that single piece is so heavy that I cannot easily handle it.  To give an example, to replace one battery in my rear-most bank, I would have to remove all the rear battery boxes, the motor mount, the motor and transmission (as a unit) and the motor controller – and then pull out the very heavy one-piece box/shelf combination.  This would literally take all day, involve using several jacks, and risk damaging things that are working fine.  It’s such a daunting task that I might rather leave a bad battery installed and simply wire around it.

When you design your conversion, keep everything small and manageable.  Your design should allow you to remove any battery block without removing anything else.  If no more than five batteries are treated as single unit, your heaviest component will be only 40 pounds.  If it’s easy to access the motor, you’ll then be able to work on your clutch without disassembling half the car.  Trust me – you’ll be glad.

As an update, my replacement BMS components have arrived.  With luck, I may be able to complete the installation next weekend.