TEG

Logisystems make a popular DC motor controller alternative to the Zilla. (Although 1000amp instead of 2000amp).

TEG

No regen, right?

JRP3

Better not be with a series motor running that voltage. Regen doesn't work too well on advanced brushes, since they become retarded on regen.

__________________
Building the AMPhibian http://amp-phibian.blogspot.com/
If you can't wait for or afford a Tesla
http://www.diyelectriccar.com/forums/

daniel

Here's a picture of the thingy on the right. Apparently it's the voltage converter that makes 12 volts from 144 volts for the car's 12-v stuff. I've flipped the picture to make it easier to read the writing.

No regen. That is correct. Paul convinced me that regen doesn't do enough good.

Very preliminary numbers. VERY preliminary. Once I have the charging cable (which they said would come Monday, which probably means late afternoon / early evening Monday) I will make some more careful tests including some longer drives. But today I took it on the freeway for a bit. The amperage jumps around a lot with terrain changes and with small differences in pedal pressure. But it seemed to draw about 150 amps at 50 mph, 200 amps at 65 mph, and back off the freeway on a surface through street, it seemed to draw about 50 amps at 35 mph. My pack holds 200 amp-hours. This gives a range of 65 miles to dead empty, or 52 miles to 20% DoD, which the battery importer told me is safe for these batteries.

The e-meter (which Paul set to 100 a-h for some odd reason) said 47.4% when I started and 11.1% when I finished my 11.9-mile trip. About a mile to the freeway, then a ways on the freeway, then home on the surface street. Since my pack is twice the size of what the meter thinks, I actually used 18% of my energy, which works out to a total range of 65 miles to empty.

I visited a friend and drove very gently home afterwards. 2.2 miles and I used 6.5 a-h. Again, that works out to about 67 miles range.

This is very discouraging. It suggests that I'm getting about 2 1/3 miles per kWh (my pack is 28 kWh). My Zap Xebra gets 3 miles per kWh measured at the wall. But it's much lighter.

Maybe I just need to learn to drive it better. But if Paul really thought I was going to get 125 miles on 28 kWh then he was assuming almost 4.5 miles per kWh.

Can anybody tell me how many miles per kWh you'd expect to get from a converted Porsche? Paul did say it would improve as the motor breaks in. He said the bearings are tight when new and that causes more friction than after it's broken in. But he didn't tell me how much of an improvement I should expect. Do you folks agree that the motor will improve, and by how much?

Attached Images

IMG_2590.jpg (13.8 KB, 11 views)

TEG

OK, so that gets you 12V from the traction battery.
Iota DLS-45 12 volt 45 amp regulated battery charger

So, I still don't know what is the motor controller. Is the black box on the left a charger or a motor controller?

TEG

My Ford RangerEV does about 60 miles from 26kWh. A RAV4EV does closer to 100 miles from a similar pack. Your Porsche should be more aerodynamic but lacks regen, so I suppose it depends on steady state cruising versus a lot of stop and go.

JRP3

EV's are usually rated by watt hours per mile, wh/mi. I consider a good EV to be about 250 wh/mi. and a poor one to be 500 wh/mi. If your 28Kw pack is giving you 67 miles of range you're using about 420 wh/mi, not great, but a lot depends on driving habits and terrain. Also air up your tires as much as is comfortable, and as much as they can safely handle.
From what I know about LiFePo4 batteries it takes a few cycles to get the full amp hour rating from them so they should improve a bit. As for the motor, I'm not sure about tight bearings, though I guess it's possible, but I do know that the brushes will probably seat more and the commutator will get a burnished patina which will improve efficiency.
If you were told to expect 125 miles of range out of 28Kw you'd have to be averaging less than 220 wh/mi since you can't use every drop of energy. I doubt your car could do that, unless you were doing maybe 30 mph the whole time. You might do a search through the EV album and see if there are other cars like yours and what their wh/mi is. http://www.evalbum.com

The motor controller will probably be mounted pretty close to the motor, so it may be somewhat buried. Did you get any literature for the components in the vehicle?

__________________
Building the AMPhibian http://amp-phibian.blogspot.com/
If you can't wait for or afford a Tesla
http://www.diyelectriccar.com/forums/

TEG

Another way of looking at is the Tesla Roadster gets ~244 miles EPA from 52kWh, so with 28kWh you would hope to get ~130 mile range *if* your car was as efficient as the Roadster. I doubt it is. Tesla went a lot of rounds of re-engineering to optimize efficiency. I think your car is basically using a lot of "off the shelf" parts not so carefully optimized. Lack of regen is one big example. I would guess you might get something like 100 mile range at a steady 40mph, but more like 70 mile range at 65mph. And that would be with air conditioning off on the flats.

As JRP3 suggested, keeping your tire pressure high could help range. You might want to find out what the highest pressure allowed for those tires. Note, upping your tire pressure could negatively impact panic braking distances, so keep that in mind if you decide to use a different pressure. The vehicle, as converted, probably has a different weight and different weight distribution from the original ICE powered car, so the factory recommended pressures may not really be appropriate anymore anyways.

vfx

Well that has to be qualified with a cost VS Paul ratio. Regen is great but if it is too much trouble (read Too expensive) for Paul then he is going to discourage you from getting it -even though it would hep you a lot.

__________________
.
.
.
.
.
.
The world loves to be deceived.

James

I have a Zilla for sale. We are also now offering a controller that is a replacement for the lower end Zilla.

http://www.evcomponents.com/SearchResults.asp?Cat=37

__________________
Tesla Roadster Foundry aftermarket accessories

The Roadster Foundry Mobile Connector (RFMC)