Battery Trays are Here.... Yay!

To be exact, 1000 trays have arrived :) So..... I have a few spare ones!

As you would know from our earlier posts, we are using A123 pouches for this conversion. We thought long and hard about how to best mount 360 A123's! We decided, no welded boxes. Instead, we used these "Joey" trays for each battery. These trays lock-in together so you can have them in any configuration you like. 

So, we are assembling 30 (96v) packs of 12 cells (240ah). We shall be placing most under the bonnet (hood for you Americans) and some where the fuel tank (gasoline tank) used to reside. We should end-up at around the same weight as the original vehicle and similar weight distribution. Here is the look under the bonnet at this stage, The trays have no batteries in them. So they are light and as a result, easy to configure..........

Once I have the layouts worked-out and the mounting brackets manufactured, I shall then populate the trays with A123's. Very neat indeed.

  Oh, the challenges of having a Citroen DS Pallas as a donor vehicle are plentiful. You would remember that we are utilising the 5 speed gearbox with no clutch. This vehicle has "5 on the tree", better known as column shift. So, the linkage was right in the way of the battery location; so we had to remodel it. Here it is...

Ready for the battery trays to go-in as per above. I am smiling, this conversion is taking shape, and those trays (Joey) work a charm...........

Watch this space.

Coming together

This is the time where we are receiving all the various parts to assemble the final product and drive it! Seems like the most elusive target but is now getting closer.

The Citroen DS offers many challenges for EV conversion, but also provides a number of solutions. As an example, no need for vacuum pumps and other ancillaries to drive power brakes, etc....

The self-contained Hydropneumatic system does all the work related to suspension, power brakes, power steering and in some cases even gear changes! So all I need to do is to drive the Hydraulic pump that used to be driven by a pully off the ICE. I have 2 choices here, either find a self-contained pump/motor assembly and retrofit to the syste, or, as is my case, I am trialling a 12 volt 500w electric motor with a pully to the pump to see if I am able to draw enough power to drive the pump.

One might think that driving all the power requirements for suspension, brakes and steering off this motor (see pic) is a big ask, and this remains to be seen. However, once one understands how the Citroen system works, it becomes clear that maybe it is not such a big ask. Without going into too much detail, the pump is responsible to charge-up an accumulator up to and maintain it at 100psi. The accumulator is what is actually carrying the constant load; meaning that the motor will only be stressed as it tops-up which is surprisingly rather infrequent in a straight line as it is the steering that requires the most power.

My Citroen expert mate suggests I put in a second accumulator in the back to further diminish the load.

The batteries are on the way........................ 

We chose A123 20AH pouches as these seem to offer the best power-to-weight ratio. It is all about reducing weight when it comes to EVs. The lower the weight, combined with civilised driving and combined with regen, might produce the range we are after or better; 150kms.

We will be using 384 batteries to produce 240ah @ 96v. But how do we mount them. Well, this possibly was the most exciting part of the project. Decided to move-away from the standard "fit them in a box" approach, and instead build trays that like lego snap together and cradle the batteries in a protective if ventilated shell. The assembly will then be cooled down (as required utilising thermo-triggered fans) to ensure optimal operation.

This is unfortunately also another delay in proceedings. We are currently evaluating early samples so we may place final order. The design allows for these trays to snap together and for a long screw to hold batches together for final assembly. We believe this is a neat and logical solution for this challenge. More on this subject in the next episode.

Battery Management System

                                 

I have just ordered the various pieces that make-up the BMS system and, being in Australia, are only a hop, skip and a jump away. They will also kindly assist me with the configuration and installation. It would be remiss of me to not also mention and thank Jaron, who has been a constant source of great advice along the way.

The charger has also arrived and the DC to DC convertor is on the way.

I was recommended TC chargers. My mates have been using them successully.It arrived 2 weeks ago and is in the process of being mounted. Heat generation while charging is an issue. So it is important to find the right location where heat easily escapes. It will probably go under the front bonnet with an extractor fan.

The DC to DC convertor is also on the way. We wanted 600w which proved hard to get. So we are utilising 2 x 300w units instead.

Feels like we are on the final stretch...... Famous last words!

But from experience we are aware that the devil is in the detail and there will be many hurdles yet to face. We are cutting it too close to Christmas, which is a bummer as we wated to utilise the break to do most of the work.

The Fun Starts NOW!

OK, so templates, couplings, decisions and questionmarks!

We are now at the stage of mating the new AC31 EV Motor to the Gearbox Bell-Housing. This is probably the most technically accurate stage of the project. We need to mount the motor while ensuring that the coupling between the gearbox input splined shaft and the motor's "keyed" shaft is 100% accurate. Anything wrong here will result in broken shafts or bearings; not a desirable outcome.

We have made a template of the Flange that mounts the motor onto the gearbox. We are going the motor located by cutting a countersunk circle the diameter of the motor so it is always achieves positive alignment once the motor sinks into the circular cut.

And here's the finished product, motor and gearbox mated, ready to get mounted in the car.

Well, there was a hiccup. The mounting plate had to have its bottom third cut-off as it hit against the cross-member in the vehicle. Yet another wait however, all's well that ends well.

Unfortunately, this stage of getting from template to finished mounting plate and shaft connector, killed 4 months as we waited on 3rd parties to get the shaft connector machined.

Back from holidays!

OK, back from a month away. What's to report?

Status

• Awaiting 10 A123 pouch batteries to arrive for testing.
• Lining up-work for matching motor to gearbox

Removing some rust from the Citroen DS

• BMS Screen

Jaron just called me and reminded me that following the above points, we are on the home run; "the challenging part" he added rather sarcastically!

Stay tuned chaps.........

Cleaning! Grrrrrrrrr........

The Citroen DS 5 speed gearbox, retained for EV conversion

This is the part I love least in my passion of restoring and recreating cars, cleaning!

What do I mean by recreating? Well, while restoring is about bringing back the original in the vehicle, recreating goes beyond restoring and includes looking at what new technologies can be adapted and adopted to take the original concept further towards that design brief that originally created that vehicle being restored.

Case in point, the Goddess (DS or in French Desse), is a statement of class, comfort, design leadership, industrial design breakthroughs and another long list of attributes bestowed on this very unique vehicle. However, there are areas the design suffered, and specifically in the engine effort-induced noise and heat generation, for which this vehicle is also infamous.

Well, whilst not truly new technology (electric vehicles have existed as far back as the late 1800's) I believe that Goddess will certainly get awfully close to truly achieving the ultimate drive experience. We're certainly committed to this.

So, back to cleaning, last Saturday, while Mark was busily slimming down the vehicle from the, now, unnecessary weight of such superfluous things as exhaust and fuel systems, I was cleaning! Yes cleaning the various gearbox parts that will be reassembled once the offending shaft arrives and is replaced. The photo above shows the resplendent parts within the gearbox. The following pics relate to the now clean exterior casing and related parts, including inboard brake calipers and bell housing.

Oh, and while here, I wanted to show you the 2 cent component that caused the breakdown in the first place, yes.......... A simple circlip!

Moral of the story? Well, not sure what the moral of the story is. But certainly, it was an undesired push to get going on my electric vehicle conversion!

The DS Engine is OUT!

Thanks to Mark's help and his engine crane, the engine/gearbox assembly was out in no time. I had disconnected most of the 1.5 million wires and hydraulic pipes and once we removed the final few that became apparent as we started extracting the engine, the path was clear for total extraction to explore what actually had gone wrong, when the vehicle, 3 weeks earlier, had lost traction!

Engine/Gearbox separation was next. As one can observe from the following pic, one can clearly see the optimal layout of this vehicle, mid-engined with inboard disk brakes. Upon separation, the Input Shaft fell-out, which should not have happened as this is meant to be held in the gearbox by a circlip; that according to Jason Hantos, (my vintage Citroen advisor) is a component that wears-out with time! 2 days of dismantling for a simple circlip that needs to be replaced.

Here is the offending shaft that needs to be replaced as the splines are showing signs of wear!

But not that easy! This is a Citroen after all. In order to replace circlip, one needs to remove the bell-housing. This is not simple as one has to remove the brakes calipers, rotors and a couple of bolts that hold the half-shaft bearings before the bell-housing can be removed.

Oh, and then, there is the gunk. The oil and dirt covering the whole inside of the engine compartment as well as the Engine/Gearbox assembly. The mechanical parts are easier  once assembled, cleaning is straight-forward. But the engine compartment and the million pipes and cables; that's another story. Tarps down, engine cleaning sprayed everywhere and a good pressurised hose-down, does most of the job. Now the painstaking detailed cleaning is a labour of love!

Before and after (still the detailed cleaning to be undertaken)!

 Following the detailed cleaning, the architecting of the new layout for the electrics starts. While this is happening, petrol tank, exhaust and all related parts need to come-out to release as much unnecessary weight as possible.

Oh, we have now decided that the clutch needs to go, unnecessary extra weight. The slow-down for effective change will be managed through regenerative braking. I think this is a neat solution!

Stay tuned..........

Research on the AC31/Curtis Controller combo

Research on the AC31/Curtis Controller combo
With some limited data, I have carried out some comparisons. Feedback very welcome.

Courtesy http://www.nappepin.com/LithiumHawk2.htm
"The drive system is made up of the Motor, Motor Controller, Intermediate Drive and Final Drive.  I chose a similar motor (same type and manufacturer) as used in the Lithium BugE.  The motor is a Model AC31 manufactured by (HPEVS) High Performance Electric Vehicle Systems. With the right controller, the motor will produce up to 50hp at 115 ft-lbs of torque.  That may not seem like a lot until you consider that 100% of the torque is available at 0 RPM to about 2000RPM before it begins to decline.  This is almost opposite to that of a gas engine which starts with no torque, climbs and peaks at maybe 2000 to 3000RPM then declines.  This AC motor has a maximum RPM of 6000 and is capable of moving a 3500lb vehicle at highway speeds.  Considering that the Lithium Hawk is targeted for under 1000lbs, you can see why this vehicle should perform well.  One more note, this motor is of course brushless and maintenance free,  The problem that you can face is overheating.  It is for that reason that I chose the much heavier AC31 over the AC20.  The AC20 can put out similar horsepower but at around 45 lbs (as I recall) it is not designed for continuous heavy loads.  I talked to the engineers at HPEVS, described my application and asked which motor would be better.  They recommended the much heavier (85lbs) AC31 without hesitation.  These are great motors operating in excess of 90% efficiency.  You'll never find an automobile gas or diesel engine that is maintenance free and operates at 90% efficiency.

  Shown are the AC31 motor, performance data (132 volt data not available) and the Curtis 1238 controller.

The Curtis AC controller is a highly programmable, high efficiency workhorse.  It is capable of producing over 550Amps of 3 phase variable frequency power and can handle a system voltage of up to 130Vdc.  Perhaps the most important feature of this AC system is that it supports variable regenerative braking. "

Looks like I need an Elcon Battery Charger
"I received the Elcon battery charger. http://www.tccharger.com/english/Product/T35/49.html This is an interesting charger in that is it auto-switching depending on the line voltage you supply it. (120VAC or 230VAC)  These chargers are custom programmed to your specifications.  Mine was programmed for a peak charging voltage of 138.7 volts which is 38 series connected cells or modules.  The peak voltage of 138.7 volts exceeds the maximum allowable voltage of my motor controller however I did that intentionally because soon after lithium cells are charged, their peak charging voltage of 3.65 volts soon drops to 3.35 to 3.4 volts.  I'll need to build something that prevents the motor controller from being turned on until the pack voltage drops to 130 volts either naturally, or by some energy bleed mechanism that I will build.  I did this so that I my nominal voltage would be closer to my peak allowable voltage.  Had I chose to have the charger programmed for 130 volts, I would have ended up with a nominal voltage of around 117 volts instead of 127.5 volts.  The higher system voltage will provide maximum power and efficiency.

This charger operates at >93% efficiency and will supply 20 amps of current from a 230VAC line voltage. At 120VAC, it will operate as a 10 amp charger.  This will be pretty handy because I can install the charger in the vehicle and have onboard 120VAC charging but be able to use 230VAC charging at 20 amps at home.

Probably the most important feature of the charger besides the auto switching is the ability to control the output current.  This is critical for the battery management system where I will need to reduce the current down to perhaps 1 amp to precisely balance the cells.  That is a topic in itself."

I guess I'll need batteries.......
"I ran load and impedance tests for 2 months on all cells I brought in including original used A123 white sleeve cells, unused A123 green sleeve cells and K2 Energy solution's LP26650EV energy cell and their LP26650P power cell.  I used a West Mountain Radio CBIII cell analyzer to test the cells for voltage drop, heat gain and energy capacity based on the actual conditions the cell would be subjected to when configured into parallel series modules.  For example, if each cell module will consist of say 52 cells in parallel and the motor controller's maximum current is 550 Amps, each cell will be subject to 550 amps/52 cells or 10.6 amps peak.  Nominal current (estimated city driven current draw) would be 70 amps equating to 1.34 amps draw per cell and highway would be 200 amps or 3.86 amps per cell.

From all of the tests, I determined that the A123s http://www.a123systems.com/ performed the best with the highest power output and lowest heat gain.  However the K2 cells exhibited higher energy content.  The K2 Energy cell is rated at 3.2Ah compared to 2.3Ah for A123 cells while the K2 power cell is rated for 2.6Ah.  I'll post some test results soon.  The voltage drop for the K2 cells was greater than the A123 cells as expected.  I chose the K2 power cells because the A123 samples had various date codes ranging from 1 year old to 5 years and some test results were a bit erratic with the capacity being less than specified.  The K2 cells netted very consistent results and performed outstanding for the conditions they will be subject to.  So I ordered 2000 of the LP26650P cells.  These weigh 82 grams each, hold 2.6 Ah of energy, can deliver 40 amps continuous and 150 amps peak.  Considering my peak current draw on a single cell will be 10.6 amps and only 1.34 nominal, I will be operating the cells well within their specifications."

Summary
I am so confused now with various claims of voltages, HP and other performance related information. Thank god for my mates, the geeks at AEVA.

What's driving my EV

The Citroen DS Pallas ev will maintain the 5 speed gearbox. The original design was that it would be a direct drive motor to diff. The Citroen DS is a front-wheel-drive with inboard disk-brakes. If we were to go direct to diff, then we would need to replace the gearbox with a diff that has inboard disc brakes. The ideal diff would be one out of a Jaguar XJ. However, this would then require modifications to the half-shafts. 

I had a great evening last night with some EV mates and received a lot of valuable feedback.

So, being our first project, it has been decided that the least complicated method is to merely mate the motor to the gearbox. This would also give us a variety of ratios to choose from to get the best performance. The next question is, do we get rid of the clutch. Having talked to an EV owner, I am now tending to want to keep the clutch. Seeing the motor has almost no internal resistance and is as a result freewheeling from its own momentum during gearchange, one has to wait for it to slow-down to a certain speed before gear change can be effected. But the final decision has not been made yet and we shall investigate this further before we make the final decision.

The motor/controller combination already acquired for this conversion are and AC-31 "C" Face AC 3-phase induction motor and Curtis 1238-6501Controller. This is designed to be installed in a EV truck weighing over 2998lbs; the Citroen DS Pallas has a kerb weight of 2948lbs.  The motor is rated at up to 70hp up to 8000rpm and 130lbs torque. More torque at lower RPM's than its big brother, the AC-50. Motor size is about 9"x 13".  At only 85lbs, it is 50lbs lighter than the AC-50. Air cooled with internal fan and sensor for controller. The Curtis AC fully programmable Controller can be used with up to 105VDC putting out 550AMPS with regeneration.

Food for thought:
Current power plant
Engine capacity         2347 cc
Maximum torque 195 Nm (144 ft·lb) (19.9 kgm) at 2500 rpm

Replacement
HPEVS AC31                 117 ft lb @ 0 - 1200 rpm @ 72v

Here's a link to somebody else that has converted the magnificent DS - http://www.evalbum.com/423

Let the fun begin!

Update

Well, a few years have gone past since I last blogged!

As you can see, the collection of Citroens has grown, however, the Citroen DS Pallas EV is no further down the track. I have instead been enjoying driving around in my "new" Citroen DS Pallas Fuel Injection (EFI) and this is a pleasure of comfort and performance. The 5 speed gearbox and fuel injection, make a marked difference to performance over my previous Carbie/automatic model, no wonder Citroen decided on this evolution.

Well, I hear you ask, what does all this have to do with EV's. In 2 words, A LOT!

 You see, the DS Pallas FI has broken a shaft or something well within it's workings and so the engine/gearbox assembly is on it's way out for investigation. It so happens, that a few months ago I had made the acquisition of an AC Motor and controller to make progress on my EV. There is a likelihood, should insanity prevail, that I will rebuild this, as an EV. Why the change of heart I hear you ask!

Well, it has been some 10 years since I took the Blue DS apart. And it has spent the last 4 years outside in the harsh elements of Australian summer and winters and it needs some major work now. Whereas, the EFI is in perfectly operational condition, only (I say only, in relative terms) requiring to be converted.

So, over the next few weeks, this decision will be made, and I'll keep you informed. I will also attempt to give you blow-by-blow progress reports.