Strut mounts in, and a new CV axle!

I replaced the strut mounts, and discovered that during the replacement had inadvertently separated one of the CV joints in the drivetrain. That made my test drive extremely short. Good news was, I knew how to replace a CV axle, had the tools, and only needed to order a new one online. Cost me $50, and I put it in this last weekend.

Electro is driving extremely nice, bumps are no longer a series of car rattles!

Need new strut mounts - work for this weekend

I've noticed for months (maybe years) that my front suspension has kind of a rattle to it over bumps. I have tolerated it long enough, and in my quest for the quieter and quieter ride, will be replacing the mounts this weekend. For those who don't know what I am talking about, here is a link from the152.com:

Strut mount replacement on VW Cabriolets

The mounts cost about $20 each, so parts aren't the big deal. I will have to compress the springs however, and that takes some work with the spring compressor I have. Fun!

You knew it was a matter of time...

I'll let these images speak for themselves...

Longest distance on record!

Since I installed my lithiums, I knew my range was theoretically longer (~50 miles estimated with my style of driving), but the longest I had traveled was 26 miles. I pushed it a little farther today, driving from Edmonds to Bothell (morning commute), not charging at work, then driving home via a longer route, through Mukilteo (almost into Everett), then back to Edmonds.

The drive data:
33.7 miles
64 Ah used

Longest distance driven by me on a single charge!

No particular negative issues, and the cells performed very well during this hilly, speedy drive, even at the end of the run - no compromised performance that I could tell. Not surprising for lithiums, but I had to test it to be sure.

This data point (33.7 mi/64Ah = ~0.53 mi/Ah) seems to corroborate earlier data points that my range with the new cells is ~50 miles with aggressive driving!

Fuse replaced, old wheels back on!

After replacing the HV fuse with a beefier variety, I decided to go back to my ol' reliable 14" LRR Sumitomos, which not only are more efficient than my heavier 'pimp-ride' tires but also handle much nicer - must be the fact that they are narrower (185s, not 205s).

And so I go, unfazed in the face of my temporary fuse setback, and proceed to get back on my Electric Horse. After all, that's what this is about right? Learning from my design flaws.

Onward! I start driving Electro again tomorrow.

'Pop' goes the HV fuse!

I knew I was asking for it.

I have a rather 'close shave' HV fuse - a 200A semiconductor Bussman - in the lithium battery pack. It's rated for 200A continuous, but can tolerate more for finite periods of time, depending on the time duration. This is what is referred to as the I-T curve. For example, the fuse will open at 400A for 10 sec, 600A for 6 sec... you get the picture.

I have been driving Electro with my battery pack for a month. 'Why did the fuse blow today?' you might ask. Well, follow along on the path with me! Each step added more instantaneous torque, which added instantaneous current draw.

1) Install the battery pack, with a nomimal HV fuse, and drive rather conservatively in city driving.
2) Install the new transmission - all of a sudden, starting in 1st gear is really fun!
3) I drive less conservatively on hills after installing my e-meter and seeing that hills don't take that much energy to drive up.
4) Sound-proof for freeway driving. Freeway driving is a lot of fun now! Especially at higher speeds.
5) Install cool-looking (but less efficient and heavier) wheels on Electro. Suddenly first gear starting from a stop requires more torque/current than before.

All these factors combined to hit my fuse today. Starting my drive home from work, I entered the *freeway* on-ramp from a metering light, *rapidly accelerating to freeway speed*, *on an on-ramp that is up a hill*, and *with heavier wheels*. POP! I got a tow truck ride home.

I will be searching for a more lenient fuse (300A perhaps) that can tolerate my driving style. In the meantime, I have reinstalled a safety fuse (500A semiconductor) in the slot, so that in the event of a calamity/short circuit it will still protect me but may not protect the pack.

Live and learn!

Doin' a lot of freeway driving!

Ever since I installed some (badly needed) soundproofing around the rear battery box, I have found that freeway driving is a lot less like driving in a wind tunnel. Go figure. So today I not only drove to work using the 'modern way' (I-5 to I-405), I found Electro handled great at speeds exceeding 70 MPH.

I was so gutsy with this new confidence that I decided to push range as well. So I drove down to the Seattle EV Association meeting near the U District and back to Edmonds, on the freeway (60-70 MPH both ways) without recharging, for a total distance of around 26 miles.

Electro's e-meter reported using 47 Ah for the trip, which is pretty close to half the capacity of my 100Ah pack.

So empirical data supports my initial theoretical estimate of 50 mile range, driving aggressively (as I usually do). Driving a little less aggressively, I could push this new range to 60 or 70 miles, but then I'd have no fun. If anyone knows me, they know I like to spin the tires :)

Silent running!

I installed the TBS e-meter this last week, and it works well! Gives me Amp-hours used, % traction pack depleted, instantaneous amp draw, pack voltage, the works. Even historical data.

Just for grins, I pulled the fuses for the brake booster and DC/DC cooling fans, which are both optional devices at this point. A little-known fact - these are the noisiest things in the car. When I disabled them, I essentially run silently, minus the subtle motor noise. What fun! My brakes are a little stiff because of the lack of a booster, but I think I like driving like this (think old manual VW brakes).

Next up... soundproofing the back cargo area around the rear battery box.

Freeway drive this morning

Since I installed the lithium batts, I have been testing in city driving, but I knew I did have the increased torque and top speed to drive on the freeway. So this morning I went for a test drive on I-5. Worked great! But I forgot that old cars have a LOT of internal noise on the freeway. It was like a wind tunnel in there! At some point I have to work on some soundproofing!

Transmission replacement complete!

Picked up Electro from the VW shop today. No major problems with the tranny replacement. Drove it home, didn't notice any difference. The real difference is that this one won't leak, and has a life ahead of it! Also the 10:1 prescaler for my new fangled E-meter is enroute from Australia, should be here in a few days! Time for some driving videos this weekend!

DOH - New transmission needed

I noticed some oil leaks below Electro the other day - yes, oil leaks. Although Electro is an EV, it still has the stock VW transmission, that has gear oil. This apparently is leaking through the differential seals that connect to the front drive axles.

So I took Electro in to a local VW shop to get the seals replaced. They looked, and basically assessed that the differential is shot and that I will need a whole new tranny. OOF.

The good news is (believe it, there is some) the tranny replacement can be done from underneath the car, and with no removal of the upper battery racks or cables. Even the motor will stay connected by one mount (the one opposite the tranny). Because of this, the VW shop has bid the job and will do it over the next week - for $1500.

I believe this is the last part of the original drivetrain, and it will soon be replaced.

Final connection pics

I forgot to upload pics of the final battery connections, so here they are. The front:
and the rear battery pack:

Here's a close-up of the connections:

As you can see, each cell monitor straddles its respective cell, and the copper interconnects go between cells. The monitors are daisy-chained together in a large wire loop that terminates at the BMS unit in the rear of the vehicle. If any one cell encounters a problem, it notifies the BMS, which can then cut power to the charger.

Right now I only have per-cell protection from over-charge, but not per-cell protection from over-discharge. The Zilla motor controller is providing protection of the pack as a whole from over-charge, with a low voltage limit of 130V (2.5V/cell).

20 miles... without breaking a sweat.

I took Electro on a preliminary range test, laptop collecting data along the way. I was fairly aggressive with my acceleration and choosing hills to climb, so I had some healthy current draws from the pack, sometimes reaching peaks of 300 battery amps on some of the steeper hills (this would equate to over 500 motor amps in some cases). I did not drive on the freeway, but man, I had the acceleration to go there easily.

Although I don't have my meter installed yet, I do know the floating pack voltage has a range of ~170V (full charge) to ~162V (lower advisable limit) - it's really a flat discharge curve. I drove 20 miles (again, with gusto) and recorded the floating pack voltage basically staying between 168-170V. Phenomenal.

I think it may be time to promote Electro to my daily driver.

It's official... I am peelin' out once again!

I had set the Low battery voltage limit too high at 152V (2.9V/cell under load) on the hairball computer yesterday, which did not account for pack voltage sag under load and hence resulted in overall sluggishness in acceleration or up hills. After dropping this limit to a more reasonable 130V (2.5V/cell under load), I could (and did) peel out from a standstill. HUGE EV grin!

I don't want to do this too much, but it is fun to have that torque when I need it.

Maiden Voyage today!

Matt and I took a fully-charged Electro, satellite radio blaring, on a 12 mile jaunt through Edmonds. Not too far, just enough to ease the batteries in and check how the newly set parameters in the motor controller are working out with the new pack.

In general, things are working well. The float voltage did not appear to drop at all from ~170V (3.27V/cell) during the whole 12 miles. I know the discharge curve is relatively flat, but this is encouraging for range!

As usual, I think my initial battery current limit or voltage limit is too constraining on the Zilla - up hills are sluggish. More tuning required there.

A few more (and longer) trips before I start going to work with this puppy!

Traction pack goes LIVE

Over the weekend I made the last of the battery connects, hooked up the DC/DC, and started the first charge. My pack voltage started at ~166V (3.2V/cell), and I was tuning the charger to push the pack to ~176-187V (3.4V-3.6V/cell).

The last thing I need to work on before maiden voyage is the instrumentation, which hopefully will be tonight. Pics soon!

Cells installed, interconnects in process

I wasted no time in getting the cells into the front and rear battery boxes. Since they don't fit exactly (I knew this in advance), I spent the first part of the day crafting some pieces of lumber to tighten up the cell packs in each box. Here you can see the front box:
and the cells in the rear battery box:


Once the cells were packed in pretty tight, I set about working on the interconnects in the front. This includes the interconnects themselves, and sandwiching cell monitors on the cells. Pretty close work, so I purposely worked on broken series sets of cells. Here is how it looks so far:

Notice the painters tape over the connects not made yet - safety first! This is where the 'light show' is going to start to become evident. Each cell monitor has a green and red LED. Green indicates the cell is in the correct voltage range. Check out the way it looks with the lights out...

Work tomorrow on the rear pack, which has twice as many cells!

Hello my pretties!

Went down to Lacey, WA today to pick up my 53 SE100AHAs. Here's a picture:


The cells came with interconnect hardware, check out this pile of copper and steel:

The interconnects are stacked sets of solid copper, with a shrink-wrap middle for insulation. Here's a side view of one of them:

I will be doing a test fit in the battery boxes this weekend. Stay tuned!

Bad Timing

I got the voicemail that my batteries are ready to be picked up, starting Monday! I am traveling on business this week, so it will have to wait until Friday. Doh! So Battery Day is now 3/5. Can't wait!

DC/DC Converter arrived

The refactored DC/DC converter arrived from Belktronix today. This DC/DC can take inputs of between 150V - 200V input, right around the projected traction pack voltage of 166V. Installation this weekend!

Battery day is 2/23 or 2/24

Called EV components today, and they reported the lithium cell shipment shows up 2/22, which means after their sorting I can pick them up in Lacey either 2/23 or 2/24. Awesome.

Lexan battery box lids installed

The lexan clear battery box lids, machined to my specs, arrived this afternoon. Isn't it a bit ironic that some of the cooler things in my EV are those things that you really can't see? They will ooze coolness by what they allow the viewer to see - the lithium cell monitoring LEDs (each cell monitor will have a red and green LED, which are lit or not depending on cell state).

Here is a picture of the front battery box...
What - can't see it? Here is another...

Either the lamp is levitating, or there is a lexan lid - you be the judge!
Here is a picture of the rear battery box with the lid on...
A little easier to see this one with the reflection!

DC/DC converter is almost done. Almost time to buy a real car battery for the aux electronics. That's another thing - the last design only allowed room for a small motorcycle battery for the electronics, which stressed under load. This design actually has one of the former traction pack spots in the front reserved for a proper group 34 car battery - so no potential for 'brown outs' in the LV circuit going forward.

Getting antsy - where are my lithiums?!

Zilla subassembly back in

I spent tonight finishing the rewiring on the Zilla assembly so that the shunt is now on the battery (-) side of the motor controller. This is necessary because the new TBS monitoring gauge I am installing in the dash will perform a real-time calculation on the energy left in the traction pack, and it needs battery current as one of the input variables (others are traction pack voltage and aux 12v).

The rest of the cabling to the Zilla, the contactor and the shunt has been reconnected, and the subassembly has been rebolted to the car wall. No pictures here, it looks pretty much the way it did before, with the exception that some of the cabling has moved around.

One note - I was informed that my clear lexan battery box lids are in the mail. All I need now are the DC/DC converter from Belktronix (soon) and the batteries themselves to finish up!

I was informed by evcomponents.com that the ship carrying my lithium cells has left China, so I guess we'll see them in a couple of weeks.

New cooling reservoir & front battery box

I have completed the assembly of the ABS sheets into a solid plastic box for the lithium cells in the front, and the box fits into the steel frame like a glove. Here is a picture:
The clear lexan lid isn't here yet, so I am working out where the cable in holes and fuse block mounts should be. Also, the new Zilla cooling reservoir, possessing a mammoth 2.5 gallon capacity, has been installed as well. Here's another pic:


I had the reservoir custom-made by a vendor that makes plastic fuel tanks. The 'customization' is that this tank has welded 3/8" ribbed fittings on both ends, for flow and cooling of the liquid coming from the motor controller. Note that the tank is now positioned in the direct airflow of the front grill, which should help in overall cooling. I used modified ratchet-down straps for the tank - looks a little temporary, but they do a nice job - very solid. If I find ratchet hold-downs that are a little more permanent, I might replace them.

Note also the fluid pump sitting nearby. That will be put in series with the tank, and will be held down by super-strong double-stick tape pads.

One week to February, which means batteries are almost here!!

Building a box!

So, as you can see from the diagrams, I have a need for a battery box in the front where I had none before - the lithium batteries are considerably smaller than the original lead acid blocks, and thus require some structural support. The rear battery box will work fine, but the front only had hold-down steel frames.

So I need to build a box.

I decided on the same material as the rear battery box (1/4" ABS plastic), because it is strong, non-conductive, and easy to work with. My cut sheets of ABS arrived yesterday in the mail, and this weekend I will be chemically welding the pieces together. Pics soon.

Another thing... since each cell will be equipped with an active monitoring/balancing circuit on top that provides visual feedback in the form of red and green LEDs, I wanted to make another improvement - clear lexan lids for both battery boxes, to be able to see the cell lights easily. My lexan lids will be arriving in the next week or two.

I am itching to get that email stating my batteries have arrived!!

Countdown to lithium battery arrival...

The SE100AHAs arrive in February. In preparation, I have been getting the rest of the car hardware ready, and creating diagrams for how this is all going to come together. Here is the front pack:

and here is the rear pack:The red/black interconnects will be copper straps provided by the battery supplier (EV components) along with the fittings. The orange interconnects are most likely 2 AWG gauge welding cable interconnects for those odd corners and end connectors.

The custom controller cooling tank I designed also arrived. It is a 2.5 gallon reservoir (much larger than the original Zilla radiator), and has custom fittings to allow connection of the aquarium pump and hose. I also have marine lock-down straps for both the tank and the larger 12V auxiliary battery that I will be ordering soon.

Counting the days!