Temperature and Projected Range for 2016

Here is the full year's graph of the eVogue's projected range vs temperature for 2016.
Summer is December to February here in Australia.
I have logged the temperatures for the drive "To Work" at about 8:30AM, the "From Work" at around 5:30PM and the "Charge" temperature at around 4AM (I start charge at 3AM and it usually stops at 5 or 5:30AM).
The magic number for 80km total range appears to be 15 degrees C.

Range vs Temperature by Day

Since I have noted temperature to and from work and charge temperature for the past three and a half months I can now verify that 15 degrees C is the magic number. Above 15 degrees and I go above (or close to) 80km projected range.

September is an excellent example (colder than last year).

October is a bit more scatty as I did a couple of "don't care about range" trips but the trend is still evident.

November has warmed up and just about every day's drive home is above 15 degrees so projected range is following.

Month by month so far for 2016.
You can see the unusually cold October.

Compared to last year.

Range and Temperature

I have collected temperature data this year in an attempt to understand a little more about what effects range the most from summer to winter.

I have logged my drive to work temperature, drive home (From Work) temperature and charge temperature.

It looks like the highest correlation with projected range is the drive home. That may simply reflect the daytime temperature of course.
Temperature is in degrees C.

(Edit: 27 Sep 2016 Updated - again)

Summer range, Getting 90km predicted

I'm getting 90km predicted range on my normal drive to work now that it's warmer weather again. My previous post showing just past 20,000km was a bad day with a few little trips. (Even EVs don't like those sub 5km local trips.)

I don't get much time to take my logging picture in the morning a we are usually in a rush to get my daughter to the station, but I did get a second shot when I saw the bad light reflection.

Range Improving for Summer

It's been a long winter - not too wet but colder for longer.
The Vogue range is returning to 80+km. With four nine 17 charges recorded for October it's looking good. It's unusual for August to be similar temperatures to June and July in Melbourne.

The Vogue is up to 18937 electric kilometers.

(Image and numbers updated 30th Oct 2015)

Midwinter 2015 range

Ah winter is here again. Range down to around 73km for 80% depth of discharge.
This pic (taken once I got home again) was from a bad day with the drive to work starting out at 4 degrees C.

Range by Month to mid December 2014

October was hotter than normal, November dropped a bit and the Vogue's range followed.

Monthly Energy Usage to Spring 2014

I have deferred the front end work until I have time to clean up the wishbones etc.
Meanwhile, I am getting good range figures now that it's warmed up a little here in Melbourne.
Here is the up-to-date range history since I have been driving the Vogue on electricity.
Range is based on 80% Depth of Discharge (DOD) of the battery pack.

The anomaly in October 2013 was caused by two high speed trips raising the average of only eight recharges. June 2013 had only five recharges. I normally recharge about 20 times a month in winter (every weeknight) and about 15 times a month in Summer.

Edit: Updated 28th October 2014

Vogue about to clock up 10,000km on Electric Power

My range is creeping back up now it's over 15 degrees C in the morning.
I quickly took this picture on the way to work. I had another 5km to go. The over-100km-projected-range didn't last long as I was about to go up a big hill - nice to see though.
(Range is Remaining Range - I should rename it sometime.)

So on the way home I'll go over the 10,000km.

Energy Usage per Month

I have noticed that the Vogue's range has increased during summer so I entered the AH used and the distance traveled for each time the car was charged since I started routinely driving the Vogue back in April 2013 (I keep a log). The data was entered in a spreadsheet divided into columns of months.
I then simply divided the AH used by the distance and averaged these values for each month.
The range line (purple) is that figure divided into 16 - my pack is 20AH and 16 is 80% of the pack's AH capacity.

The result. (In Australia the hottest months are January/February - coldest is around June/July).

Energy usage per kilometer is on the way back up as it gets colder down under.

(Edit: Graph updated again June 5th 2014)

It's not aligned but here is the temperature graph for where I live. The grey area is the rolling average.

Source of graph: http://weatherspark.com/history/34069/2013/Melbourne-Victoria-Australia

This week's economy

Figures for week ending 2nd August 2013
Monday: 8.34 AH for 39.42 km => 127 Wh/km
Tuesday: 6.36 AH for 30.84 km => 124 Wh/km
Wednesday: 8.94 AH for 40.4 km => 133 Wh/km
Thursday: 8.37 AH for 36.38 km => 138 Wh/km
Friday: 9.24 AH for 42.84 km => 129 Wh/km

All battery to wheel.
I increased the available regen torque to 45% of forward torque this weekend.
I doubt it will make much difference but may slightly increase my overall trip speed as I can slow down faster.
We'll see.
Still waiting on my eBay accelerometer so I can do my own on-vehicle tailshaft balance.

Only One Fuseholder Remains - Economy Figures

I didn't post it at the time, but last Tuesday night I removed three of the last four inline charger fuseholders. I have one left and it's only there because I ran out of 4mm black heatshrink and it was the only one that looked to be in perfect condition. I'll do it as soon as the heatshrink (from eBay) arrives. With the fuseholders gone the Vogue was completely trouble free for the commutes last week.

Figures for week ending 26th July 2013
Monday: 8.84 AH for 39.2 km => 135 Wh/km
Tuesday: 6.68 AH for 31.9 km => 126 Wh/km
Wednesday: 7.20 AH for 33.6 km => 129 Wh/km
Thursday: 9.81 AH for 43.4 km => 136 Wh/km
Friday: 9.38 AH for 42.9 km => 131 Wh/km

(All battery to wheel)

As a curiosity, I usually make it to work at about 3 AH consumed - that's around 1800 Wh making the economy about 120 Wh/km (my record so far is 2.8 AH). The trip home is a lot worse and I have generally racked up over 6.6 AH by the time the round trip is completed. The difference in altitude is about 20 meters so doesn't explain it - but driving style does. Going to work I am generally not hassled by any other drivers so I can accelerate slowly and slow down at my leisure taking full advantage of regen braking. Driving home is a relentless wrestle with other road users to use as much regen as possible but not get in their way. The nett result is that driving home is less efficient. Accelerating up hills costs a heap of capacity.

My observation is that not many drivers are in a hurry to get to work, but most road users are in a hurry to get home.

I could improve this situation with more regen. At the moment it peaks around 25 Amps (battery) which is 1.25C. Headway (battery manufacturer) recommend a continuous charge current of of 1C (20A) and maximum continuous charge of 2C (40A). Perhaps I'm being too conservative. I really haven't had much time to mess around with configuration in the past few weeks.

Economy figures for last week

It's actually been interesting driving the car in these colder months without a heater. The economy is slightly worse than when it's warmer and we can't blame the heater!

Figures for week ending 19th July 2013
Monday: 5.89 AH for 24.8 km => 142.5 Wh/km
Tuesday: 6.78 Ah for 30.6 km => 133 Wh/km
Wednesday: 10.34 AH for 44 km => 141 Wh/km
Thursday: 7.62 AH for 34.25 km => 133.4 Wh/km
Friday: 7.61 AH for 31.7 km => 144 Wh/km
*Friday after at-work charge: 12.6 AH for 50.67 km => 149 Wh/km

As usual all figures are battery to wheel.
I didn't really have to charge at work on Fiday but I had a Chiropractor appointment in the morning then I chose to do the running around on Friday night in the Vogue. It's two trips to Doncaster and back and the big hill takes it's toll. So much for "the most I have driven in the last few years during weekday is 58 km".

Economy Figures for Week-before-last

I forgot to post these. I didn't drive the Vogue last week but the week before with the controller switching at 8kHz and me driving the lowest speed roads I could find for my commute returned some excellent power economy.

Economy figures for the week ending 3rd May 2013:
Monday 9.46 AH for 43.4 km => 131 Wh/km
Tuesday 6.33 AH for 30.77 km => 124 Wh/km
Wednesday 6.55 AH for 30.8 km => 128 Wh/km
Thursday 10.28 AH for 44.9 km =>  138 Wh/km
Friday 6.77 AH for 32.4 km =>  125 Wh/km

As always, all battery to wheel.

Economy for Last Week and Full Current at Stall

Power economy was pretty similar to last week.

Week ending 19th April 2013:
Monday 11.86 for 48.92 km => 145 Wh/km
Tuesday 10.1 AH for 48.1 km => 126 Wh/km
Wednesday 7.33 for 34.12 km => 129 Wh/km
Thursday 9.93 AH for 39.5 km => 151 Wh/km
Friday 10.75 AH for 47.83 km => 135 Wh/km

All battery to wheel.
Thursday was the day I recorded serial logs. Typical that it was the worst day.
The Vogue has now traveled 636 km as an EV.

Friday I played around with different PWM frequencies. I hadn't realised that I wasn't getting full current at stall until I tried 4 kHz flat-top (see previous post). Suddenly I got good acceleration from stationary. The only problem is that 4 kHz is annoying. I tried a few combinations during the day and was only on the last trip to Doncaster (up a significant hill) to pick up William (son) that I tried the last pre-supplied switching frequency combination.

It's 8 kHz SIN auto-switching to 2 kHz  when current exceeds the 8 kHz limited value.
It works perfectly. I had full current from standstill, same as the 4 kHz configuration but no noise when not heavily accelerating. Unlike the 16/8/2 kHz configuration, it apparently applies the correct current limits when switching PWM frequencies.

It made a huge difference. There was a small hill turning out of a driveway that William and I had always wondered if the Vogue would handle once it was going (challenges of direct drive). It was no problem. It may have been another story with the 16/8/2 kHz configuration that I have been running since the car was on the road.

I'm not driving the Vogue this week. I have decided that I'm shaking it to bits (a couple of the chargers have rattled their voltage output down by half a volt or so - trimpot movement) and I need it going for Sunday. With Thursday a public holiday here, I'll do the axle stand thing again and check out Richo's (AEVA) theory that it may be resonance in the motor cradle. I'll also be a lot more critical of which end the vibration is coming from.

Heater Failed this morning

Ah prototypes...
Since it's the start of the cold weather in Melbourne, but not TOO cold yet, I thought I'd better run the heater for more than a few seconds. So, this morning about 1 km from home I turned on the heater, directed the airflow to "screen" and put the control about halfway on. The screen cleared almost immediately (it wasn't bad to start with) and the cabin warmed noticably within a minute or so.
I figured I'd save range so shut off the blower (fan). History: The heater PWM controller runs from the +12VDC feeding the fan, so when the fan is turned off, the heater controller stops feeding pulses to the IGBT and the heater core stops getting any power - or that's what SHOULD happen.

What actually happened is that a slight smell became evident in the cabin so I quickly turned the blower back on. I was stopping for a small errand in about one kilometer so I didn't pull over just then. Once my errand was done (just a pick up) I started the Vogue (closed the 600 V contactors) and saw that there was a 1.6 A current draw. I shut it off again, opened the bonnet and unplugged the conveniently located heater 600 V  power wires (not sarcastic - I didn't trust the heater controller as you can see from other posts about "heater"). Such was my distrust that I hadn't even mechanically anchored the wires yet so it took all of 5 seconds to unplug them.

I'm glad they are finger proof (heatshrunk Anderson PP35 connectors) because I totally forgot to wait the 30 seconds for the controller bus caps to discharge so they were essentially "live".

So it appears my PWM controller experiment needs more work.
For the technical folk reading the blog  - my heater controller circuit.

It probably needs:
1. Zener across IGBT gate - I thought they were built in - it seems not.
2. Larger bus capacitance. 1uF is probably extremely optimistic.
3. Better IGBT heatsink. I used a little flag one assuming the blower would keep it cool. (The control board is mounted on the blower/inlet side of the heater core).
4. There is also no negative voltage on the IGBT gate for safe switch off - hmmm.

A lot of these decisions were based on me thinking that the Ceramic heater core would not be very inductive - I need to test that assumption. The 1.6 A current draw suggest that the IGBT is NOT totally shorted - more dangerous than if it was (fire hazard). It will be interesting to see what is really going on.

The heater was finished before I had 600 VDC to test it so this time it will get a full test before re-installation. It's pretty easy to get the heater box out - no dash disassembly or such involved and everything just plugs in (famous last words).
I shouldn't need the heater for a couple of weeks yet so it may have to wait until after the 28th April when the Vogue is involved in a display.

**Addition 16-Apr-2013 I should also slow the PWM switching frequency down. 16 kHz is not necessary. I think I'll slow it down to 100 Hz. This should remove the necessity for some of the other possible changes - bigger caps, negative gate voltage.

Economy figures for the week ending 12th April 2013:
Monday 14.1 for 58.8 km => 144 Wh/km
Tuesday 7.22 AH for 32.06 km => 132 Wh/km
Wednesday - forgot to record it.
Thursday 8.6 AH for 39 km =>  132 Wh/km battery to wheel.
Friday 11 AH for 50 km =>  132 Wh/km battery to wheel.
Saturday 2.3 AH for 9 km =>  153 Wh/km battery to wheel (three 3 km trips).

First trip to Work and new Tyres

I drove the Vogue to work for the first time today - partly because the tyre place is over the road and partly because a couple of colleagues that have been following progress are leaving at the end of the week.
I now have Hankook 185/65R13 Enfren tyres on the car.

The Vogue on it's new silicone.

The guys (and gals) at work were uncondionally supportive and it was a immense relief to have other people see the car actaully working, not just a web page.
The trip went without incident. To and from work is 30km total, the other 8km was joy rides which cost me around 15km in range - hmmm! (Whoops. I realised that I didn't take Eastlink so my trip was 17.1km one way - possibly more going home. That makes more sense.)
By the time I arrived home tonight (Odo=110km), the total was 38.21km travelled with 9.01AH taken from the pack. At 600V that's 5400W/hr with equates to 142wh/km. The dash showed remaining range as 29.40km to 80% DOD (I allowed 16AH for use).

While we had the LEAF on trial we got around 170wh/km so I'm really happy with the figures.
The drive to work was on 70km/h and 80km/h roads so the 67km projected range for 16AH is pretty much on the button from Woody's (AEVA) spreadsheet.
Since the trip to work was on the old cruddy tyres, next time should be even better.

I still have a tailshaft issues which I think now must be differential pinion angle.
My target for the moment is VicRoads approval so everything else can wait. I pick up the polycarbonate partition for the boot tomorrow and I'll be preparing the car for inspection over the Christmas to new Year break.