Energy Matters Forums

[offgridQLD]

Unlike a conventional car where you usually see a improvement in your fuel consumption on the motorway . Say a typical car that consumes 10lt/100km in the city traffic could achieve as low as 6lt/100km on the motorway at a steady 100kmh. That's a 40% improvement.

With A EV it's usually the opposite to this. While on a flat motorway at a steady 100kmh. My range might be only 100 - 110km . If I drive around a flat city in traffic I might be able to achieve 200km range in a 0 - 60kmh zone.

Typically if you live in a flat city like Adelaide you will have a better range than a very hilly city like the north/west side of Brisbane.I don't drive anywhere without going up and down lots of small but steep hills and a few 100 - 250m high climbs. It sucks a set amount of power to shift weight up hills no matter what speed you climb at and there is no way around it its just the laws of physics. Roughly 1.8kwh of power to shift the Imiev's weight 500m of altitude gain.

Calculating the range at 135wh/km is a good safe number to work with as a good average that covers for the unexpected and changing consumption you face day to day. Sure If I hyper mile and drive for max efficiency I can get more km out of each charge. There really isn't a need to stretch every last bit out of it . It's no fun driving that way. I like to just get in a drive it like I would any other car. It's the people driving the big V8's that are feather footing around adjusting the flow of the money pipeline directly from there wallet to the motor


Kurt

[Gordon-Loomberah]

Hey Kurt, have you thought of racing it?

http://reneweconomy.com.au/2013/video-o ... rack-64622

[offgridQLD]

Yes EV racing it dose make for a boring spectator sport. Fun if your the driver

You can hear a EV coming along the road from wind and road noise. Though they are way quieter internally and externally when you get up them. Plant your foot to the floor and all you get is the sensation of being pushed into the seat.

It takes some adjusting to the sensation as your expecting a big noise to go along with it as the motor revving up like a petrol engine. I like how you can accelerate hard from a traffic light or have a bit of fun with it without making a big fuss/ noise and drawing attention to the car or disturbing the neighborhood.The engine revs to 10,000r rpm try driving a internal combustion engine around the suburbs that revs to 10,000rpm and you wont be very popular.

Kurt

[offgridQLD]

Some interesting comparisons between a internal combustion engine and charging the Imiev with fossil fuels.

Searching some specs on our Kubota J108 generator its rated at 3.1 L/h at full load (8kw). A typical numer used is 387g - kwh .Using 135wh/km as the imiev consumption (conservative imiev average consumption) works out to 5.2lt/100km of diesel to charge the imiev.

There are generators out there than consume as low as 190g/kWh 13.5 x .19 = 2.6 litres/100km. Efficient home based generator + Imiev as basically a Separated hybrid car. At 2.6lt / 100km It sure is a simple package. The consumption is better than a hybrid dragging the weight of a generator around with you all the time.

I guess this is just a testament to how efficient the imiev is . Even with all the conversion and charging losses using a generator its still more efficient than most cars.

I don't plan to use this as my charging method but its nice to know if you just needed to top off the battery in a pinch or run of bad weather. its still very efficient compared to the alternatives.

Kurt

[offgridQLD]

Today we had a go at driving our Imiev from Brisbane to our off grid house in the sunshine coast hinterland. Total distance 104km with 500m high + climb at 12% grade into the hinterland along with hilly and undulating sections along the way. The goal is to make it with a 2kw safety margin on the SOC.

We made it to the house 104km with 2 bars (2kwh) remaining on the SOC gauge and 9km on the RR gauge (though the RR was mare as its predicted from the last 20km were and all of that was uphill or undulating). We had a good load in the car to. two adults and one child, a Engel fridge(40kg including the food inside), luggage 4 bags 30kg and the charger.

Parked the car in the shed at 11AM unplugged the air compressor and started charging. The solar charge controller sprung to life to cover the load.The inverter was showing around 2400w AC output 2 200w was the charger and the other 200w was the idle house load.

Looking at the solar charge controller it was pumping around 3300w into the battery's to hold float.35% loss. 5% of that loss would be charging the lithium's in the I miev. 10 - 15% would be inverter loss and the remaining would be flooded lead acid battery's that are not very efficient. When I switch to lithium's on the House in a few years there will be a big improvement in efficiency. The bat voltages in the pic were taken befor the charge controller had a chance to creep them back up to float voltage and hold steady.

Anyhow it shouldn't be a problem At the moment I am just using the 3960w of PV that's on the roof NE facing. When I have time I will put up the additional 4200w on the NW roof of the house. I thought it would be a good idea to get up on the roof and clean the solar panels as I have been lazy and the last time I did it was over a year ago [img]smileys/smiley36.gif"%20align="middle[/img].

I will most likely pump 7kwh or so into the battery today and top of with another 7kwh tomorrow for the drive home Sunday afternoon.I should have 3 or 4 bars (kwh) on the SOC gauge on the return trip as I am going down the range.

Its 2pm now and I have just about pumped 7kwh back into the Imiev's lithium battery 1/2 full agin. Because the PV is NE facing I will switch it off soon and top off the other 7kwh tomorrow for the return trip.Funny today was the first time I have heard the fans on the selectronics inverter come on and only for a short while after charging for a few hrs.

















Kurt

[offgridQLD]

Edit above 27% loss from charge controller to GPO not 35%. Also any losses in charging the car were already included in the power meters reading.

Kurt

[davidg]

Edit above 27% loss from charge controller to GPO not 35%.

Very good compared to grid generated power losses much higher for that .
Whos the person on the far right?

[offgridQLD]

Whos the person on the far right?

My wife asking if we can use the dirt from the PV to level the driveway

Kurt

[offgridQLD]

Pumped another 7kwh into the Imiev's lithium battery today and its just finished balancing . The tank (battery) is full and ready to drive back to Brisbane . The house battery's will be on float in 1hr or so. The extra 4kw of pv will be a good match.

The max internal temp our selectronics inverter got to after charging the Imiev today was 38C internal I think the fan kicks in at 40C transformer temp was 58C (the transformer temp doesn't change much with or without a load). Fans on the charge controller kicked in every now and then .

We usually spend around $30 in unleaded petrol to dive up to this house and back each weekend.I'm not going to miss that at all.

A total of 14.2kwh returned to the car (measured at plug) 16kwh battery full again.



Kurt

[offgridQLD]

I made it home again on just 11kwh of battery. Just going with the flow of traffic 100kmh on the motorway and speed limits in the other areas. I found regen down the range was great though started to be limited around 3/4 way down as the pack was getting almost full again

Efficiency on the way back was around 110wh. Great feeling zipping down the motorway at 100kmh from the weekends sunshine

The charge efficiency of the lithium is great really only a few percentage loss when recharging plug to battery.

Kurt