DC-DC converter installation and update

The DC-DC converter happens to fit in the old engine air-box.  This will provide good airflow to cool it, keep it dry, and it is already shock mounted.

UPDATE: on usage. We noticed the DC-DC converter was not shutting down as expected when the car was turned off. Best current guess as to failure mode: DC-DC would turn on as soon as the voltage was high enough to activate it. That would occur as the pre-charge circuit on the main pack was engaging. We were counting on this pre-charge slow activation to shield the DC-DC from a voltage spike, but in doing so, the current draw on the pre-charge circuit before the main contactors closed caused the main contactors to wield closed. While trying to diagnosis the issue the main disable was pulled leaving 380Vdc across its contacts. The system did shutdown. A solution has not been determined yet beyond the need for another pre-charge circuit, and/or control of the DC-DC on/off internally. New main contactors have been ordered.

Charge anywhere?

We have found that the standards related to 220VAC outlets has changed over the years.  There is no knowing what outlet will be available at any location.  The car can either carry several dongles, or we were pointed toward a more universal solution.

We built this solution and have had several occasions to use it.  The theory is that any house with 220V service has multiple 110V outlets on either leg of the 220V.  Therefore if you plug one 110V plug in to the wall, and then find another outlet that lights the neon light between the two blades you will have the 220V needed to charge.

In practice we have found that it is imperative to carry a circuit tester like:

Our first attempt to use the adapter box system pointed out that in one of the outlets the Hot Line was on the round ground pin, the White Neutral on the Hot blade and the bare Ground on the neutral blade.  We blew a fuse and went on to find that many sockets in the house were all wired "randomly".

The second location we attempted to charge at had reverse polarity on some outlets, and we also have come to the conclusion that this system will not work with any GFCI protected outlets.  As universal as we expected this solution to be, it has not panned out well yet.

Weight and balance of eGolf

Included are the original posts to ease comparison.

"
Measured weights no fuel
Borrowed some digital scales.

Lbs                     L        R     2674       
  F                    897    750     147    62%  
  R                    502    525     -23    38%   
Difference        395    225               
                         52%   48%

W/153lb Driver    L        R    2827   
  F                      953    774    179    61%
  R                      555    545      10    39%
Difference          398    229   
                          53%    47%

Best current guess is the car will gain 500lbs to 3200 lbs total w/o the driver.  Most of the weight gain would be in front of the rear wheels under the rear seat with batteries.

EV version guesses          
Lbs                     L       R       3174
 F                      897    850      47     55%
 R                      702    725     -23     45%
                         195    125   
                         50%    50%
"

Actual eGolf numbers
Lbs                     L       R       3076
 F                      965    917      48     61%
 R                      575    620     -45     38%
                         390    297   
                         50%    50%

Original weight 2674lbs+ 15 gallons fuel (90) = 2764lbs
eGolf weight                                                         3076lbs
weight gain                                                        = 312 lbs gain.

DC-DC converter bought

Several test drives have been done, and a couple have been longer than expected.  The issue seems to be that as the 12V car battery system voltage droops the DMOC adapter shuts off power to the DMOC.  So the last two weeks have been used to research DC-DC needs and options.  The 403Vdc max of the Nissan Leaf system seems to limit the option significantly, and looking at many EV websites no standard option was found.  From previous blog notes, we note that the original alternator in the car was capable of 90 amps.  An ammeter was placed on the main battery positive terminal and readings were taken:
Car OFF:  no resolution
Ignition ON: Spike, 10A : Steady state, 4.5A
+DRL's ON: Steady State 20A
All things on that can be controlled: Spike, 80A : Steady State, 50A

Therefore minimum 450W, Steady max: 600W, Spikes: 1000W

Vicor provides two current options, the 3623 and 4623 chips.  The chips can be had on evaluation boards.

Two of either board would be needed.  Available from Vicor for $1610.  Or Digikey for $1323.

eBay was scanned for alternate options.  It was found that old Vicor PFC Mini, Maxi, and Mega power converters could be applicable but less efficient.  On the Mini versions the outputs are usually printed directly on the main sticker, but on the Mega units the main sticker does not tell about the outputs and unfortunately most retailers do not seem to recognize that the numbers are on the individual modules and require closer pictures to identify the many different outputs.  Eight outfits were contacted to collect the output information.  Five of the stores responded with the identical ?stock? answer "Thank you for your inquiry. A picture of the sticker with all of the information is in the listing. If you are interested, please make an offer via eBay and we will review it. If you have any other questions or concerns, please advise. Thank you and have a nice day."

Thanks to:

An eBay Store

Alternately a used Vicor PFC Mini PM1-03-576 was found on eBay. 

It is rated at: Input, 115-230Vac 10A: Output, 12V/99.9A
Despite these being listed as A/C input, the user guide specifically says they are rated up to 380Vdc input. Their output capability is 600W/module but derated in the pack to 500W/module allowing 1500W max output as the -03- designates this unit has 3 modules in parallel.  You can see the bus bars connecting the three modules in the above image.  The Output voltage can also be adjusted between 8 and 15V.

VIDEO

We can build cars, but you would think one of these young folks would now how to use a phone.

Kudos to VSDC Video Editor for being intuitive enough.

"C" Programmers out there?

A "C" language programmer would be very helpful right about now to help with the debugging process.

We have 5 computers to connect via CAN: Nissan BMS, VW car, Azure DMOC, Brusa charger, Wolftronix adapter.

If you have time and willingness to read some documentation we can use help programming the adapter to be the communication hub for the 4 other systems.

AND

EUREKA!

Videos to come soon!

Plates acquired for maiden voyage.

We waited to late, when the DRL's turn on the car battery voltage dropped too low to run the computers... Videos another day.

Computers

We turned it on Thursday March 19 at 10pm.  NO SMOKE!

It still has not moved, we have an error light on the test box we are struggling with one step at a time.

A "C" language programmer would be very helpful right about now to help with the debugging process.

Volunteers?

Looking for a sounding board

It seems that tomorrow March 19, 2020 will be the day of first power.

We are looking for anyone in the Champaign County Illinois area that has sound logic and familiarity with Nissan, VW, electric car systems that is willing to sit with us as we walk through the system before turning it on?

2020

All the 2020 posts have disappeared. 

So the quick update is that we think we are within days of getting it to roll under its own power!

Let's try and catch you up, the order may be a little out of actual sequence.

Top center coil of wire was for the O2 sensors.  The entire bundle has been removed all the way back to the old car ECM. Coolant tank in place, (center beige ball).  The main port will connect to the old radiator, new motor, new water pump, and new DMOC (Motor Controller).  The upper tank connection that can be seen will be connected to the old heater core in the old heater core in the cabin, a new pump, and new heater element.
The Nissan LEAF main battery disconnect box (orange and green at the center left) contains the main battery pack fuse, and the top green/orange part can be remove to disable the main battery power.
The windshield wiper fluid bottle is there but not filled yet, you can see the dash warning light below.
The gap just to the right of the windshield fluid is for the power steering pump.

(Looking down just behind the firewall up in the windshield wiper area where the old car ECM is.)
Right in the center you can see a bundle of wire connecting to the left connector on the old ECM.  Adjacent to the right of it we have been able to remove the entire second wire bundle as it controlled the old engine.  You can see in another photo below some of the error lights caused.  This bundle will be wrapped back up soon as we figure out how to fake the old codes.

Old car battery back in the lower right and reconnected. 
Most of the old car systems are back up and running including the ABS, and Airbags without change. 
The BMS (orange center) harnesses have been connected and the Nissan Leaf BMS is completely connected now (lower left in glass case under wire bundle). 
Top just to right of brake fluid reservoir are the relays that ran the old car emissions systems, they will now run the new computers and DC-DC converter. 
Hole just above the old main battery will be the location of the DC-DC converter (was the old engine intake airbox).
New recessed battery covers (white) in place, they will be clear before being sealed down (white plastic coating will be removed).

DMOC adapter (new computer, black, top left of glass case has been installed.  Connector pins came in yesterday to hook it to the car, when this is done the car should be able to move under its own power!

Under dash, looks like a regular car, counting left to right, 3 red wires, then a black wrapped blue wire, just above it is the VW fuel pump relay (black with white circuit diagram printed on it).  This will power the new systems relays.  IF the airbags deploy, it should automatically disable the new systems and disconnect the main battery power.

Note the Blu wire in the center right edge labeled "1".  It goes through fuse 28 (15A) and then will power the DMOC adapter.  Note in the center of the schematic the "Supplemental Restraint System" wire.  if triggered, it shuts the relay down.  (Thus not pumping fuel after a crash...)

Lights;
Parking brake pulled, therefore "BRAKE" light on.
No windshield wiper fluid in bottle yet...
No coolant in coolant tank yet....
EPC, O2 sensors removed, need to figure out how to fake the system.
Engine light, ooof, so many things light that up that do not exist any more, may be a piece of black tape...
Coolant temperature gauge works.
Fuel gauge will work again.

Rear suspension reinstalled with shocks.  Ride heights look real good.

Ongoing task, determine what size DC-DC converter we need.  We need 400V to 12V (13.5-13.8).  We will shortly put an amp meter on the VW side of the car and see how much the old system pulled max with fan, radio, headlights... BUT WE HAVE NOT FOUND ANY SOURCE FOR 400-13.X volts yet.  Help Please.

Main electronics box installed, Charger installed

The main electronics box has been placed in the car and wiring it in has commenced.

The small blue wires seen at the top of the box are from the rear battery sensing and will go into the BMS. The black and red wires in the same area are for the rear battery pack internal solenoid.

The 3kV Brusa charger is installed where the muffler was. The power cables can be seen in the pictures above entering the main electronics box, and the charge port has previously been shown installed in the OEM fuel filler door. They are also connected. The OEM cooling fans will need to be re-attached to the bottom between the angle iron rails as the fans would have been in the wheel well.

The high voltage box

The box is made out of polycarbonate, it may scratch easier than acrylic, but it has a far higher impact rating.  The hope is that if anything goes wrong in this box at least it won't be conductive to the outside.

END DAY ONE, WE SHOULD HAVE STOPPED ONE CUT SOONER, no blood and I was standing to the proper side of the blade to avoid the arrow.

And yes, the hood does close properly without contact!  You can see the gray conduit and blue sensing wires coming up from the rear battery box to connect into the top set of holes in the back of the box.  That section is split because the cables already have connectors on them.  The electronic components will be screwed down in the box with Nylon bolts, and all but the top will be welded together with a bond agent.  Once the conduit is routed into the box there will be space for the DC-DC convertor just behind the original main 12V battery.  We have still not purchased the DC-DC convertor, suggestions are welcome.  400V Nissan Leaf pack to 12V ~60amp needed.  

Rear battery pack installed.

A new rear seat pan will be created to seal all the "orange" below the car.  The new battery box actually only intrudes into the cabin in the corners nearest the rear and only 5mm.  The other 99.5% of the battery housing sits below the existing body pan.  The rear seat cushion bottoms will be trimmed slightly, the rear passenger area will be have no perceivable change once the seats are in.

D a r n, forgot to get picture with the rear axle back in, it sits below the rightmost line of nuts and clears the box at all positions.  The top left of the pic is the rear tire well to help orient you.  The bolts will be trimmed to length before we are done.  The pack is held in by 7 8mm threaded rods, 5 are the original fuel tank mounting points, and two additional were added to prevent the battery pack from buckling above the axle.  Sleeves were placed on the threaded rods such that the joint could be pulled tight and cannot move up or down.

Look at that, the power lines come out right between the parking brake lines. :)  The original parking brakes are reattached with no routing changes, and the original brake lines are reattached with a 30mm change in routing.

NEXT STOP, Creating the front main power junction and control box. It will be made out of clear acrylic and house:
The two main power relays
The Pre-charge circuit
The Nissan Leaf BMS
The battery heaters relay
The charger junctions.

Rear Battery pack continued progress

The rear pack has been stuffed.

Kilovac LEV200H4ANA Solenoid The main POS must be turned on before the main cable leaving the pack is live.
The terminals were also covered with insulation.

Installing the bus bars and BMS wiring.

Installing the bus bars and BMS wiring.

Installing the bus bars and BMS wiring.

BMS wire management.

Wires left to right: Main solenoid control and confirmation, Main POS out, Main connection from 20 modules to 6 modules, heater connector, 12 pin BMS connector, heater connector.

20 module ready for install.

6 module connected and shield in place.

20 module beginning decent.

20 module 2 module deep.

20 module 95% deep.  Now the supports are unscrewed to finish lowering into place.

Next task, drill the stud holes through the lid and caulk the grooves to seal the box.
There will also be a breather hole in the lid center with desiccant.
Next step, put it up in the car.

Rear Battery Pack

We left you last year fitting the rear battery pack and finally figuring out the pins for the BMS.

Since then we had a dead 2001 GTI  with 200,000+ miles donated to the cause for parts as it is the same body.  The GTI is currently running errands around town until parts are needed.  We also paused for the push of several students completing formal education.

 Getting restarted.  A nearby lift was donated for a couple of hours, checked the fit again and finalized the installation points.


Hurrah for folks that work on car restoration more often, they had a better idea on holding the pack in place.


Perfect fit, front of rear battery box to frame rise for original fuel tank.  Original fuel tank mounting bolt holes to be reused.


Battery box pigtail s will exit directly into old exhaust tunnel.  Bottom of tunnel will be closed for protection.  Large hole is for the sensing wires.  Small holes are for the pos and neg leads.


Added brackets to hold rear of box to floor pan just fore and aft of rear frame beam.  Some days my welds are prettier than others.  Thank again to friends for the lessons and equipment usage.


The above picture of the welded brackets straddle the frame here.


Battery box complete.  Steel tubes will be placed between the brackets and the frame to allow for proper bolt tightening without air-gap.


Reconfiguration of safety plastic


Rear 6 pack installed in box with safety plastic


Rear main pack 20 modules with safety plastic and lifting brackets


Reminder of what it is supposed to look like.

Next stop, wiring all the sensor wires in the long pig-tails that go up to the BMS in the engine bay.