Phoenix Range Test Sept 15, 2012 planning!

[adric22]

When will we be able to see the raw data collected? Or did I miss something?

 

[keydiver]

Probably tomorrow, from other posts Tony has made.

 

[edatoakrun]

At what temp and at what rate did you charge to get that 250 gid reading?

Temps are listed in one of the previous posts ^^^ up there. All charges were topped off with a Blink L2, however, some/many were started with the DC charger. My car arrived with about 60% in the battery from San Diego, and we DC charged it to some value higher than 60% (it didn't take long), then topped off with L2. All cars were parked outside in the same ambient air. All cars had a minimum of 4 hours between the end of charge and the test drive...

I doubt the ambient temperatures at the test start location were very significant to your (or anyone else's) battery pack temperature at the time of charging, other than for LEAFs parked there for many hours before charging.

I would think the temperature of you battery pack would be primarily determined by the ambient temperatures during the (six to twelve?) hours immediately before your charge (while you were towing your car from San Diego to Phoenix, right?) and any additional heating from the DC and L2.

Please post with the other data, whether you observed anything other than six bars on any of the LEAF's temperature gauges, at any time prior or during charging.

 

[shrink]

Tony,

I just e-mailed you. I think I have access to a 1-month old Phoenix LEAF. It was leased a month ago, but who knows how long it was sitting on the lot.

 

[edatoakrun]

="TonyWilliams"

Does anybody in Phoenix have access to a very new LEAF that one of our volunteers can drive for 84 miles ? A dealer?

Unfortunately, even a newly purchased LEAF in Phoenix is already likely to have advanced battery degradation just from sitting in the brutal hot Phoenix sun on the dealer's lot. So, any possible candidate LEAF would need to first pass the Gidmeter test at 100% charge.

Then, I'm confident we could find a volunteer to make that early morning drive in the same weather conditions we experienced Saturday...

Is there some unique quality to Arizona roads or atmospheric conditions you're looking for?

Can't you replicate the same constant speed near-level driving conditions at the same temperatures, over a large part of the USA today?

There should be plenty of new LEAFs all over the country (with the gid counts you want) that could run this test for you.

I'd be tempted to try an I-5 loop myself, but it's ~50 miles from here to the nearest long, flat stretch of freeway.

If anyone else with a less-than-new LEAF wants to judge their own batteries capacity against the Arizona test group, I'd suggest only trying to see how your car matches the AZ cars to from "100%" to VLBW, which I expect will be posted.

 

[MrIanB]

Do we have any pixs to share?

Thanks,

Ian B

 

[TonyWilliams]

Is there some unique quality to Arizona roads or atmospheric conditions you're looking for?

Can't you replicate the same constant speed near-level driving conditions at the same temperatures, over a large part of the USA today?

Yes, the route could be duplicated anywhere. Level dry highway at 1130 feet elevation and 80 degrees, with light winds. That gives us about 2600 feet density altitude. Out and back to mitigate any wind. I don't want corrected data (e.i., sea level, but hotter temperatures to arrive at the same density altitude).

North of me is Temecula, California at 1300 feet, with two largely level freeways going north (15 & 215). Very similar to Phoenix heat and humidity. So, if somebody has a NEW car there, that would work. Plus, we may have one in Phoenix tonight, assuming the weather has remained the same. I will meet anybody there early in the morning in Temecula. It's kind of PATHETIC that I couldn't get this from 3-4 month old cars, one with only 2500 miles.

I will continue to compile data tonight, and hope that I have new car data by Tuesday morning.

 

[DaveinOlyWA]

temperature i can reproduce since it will be warm but the elevation will be a challenge. its mostly under 300 feet around here and when you do get over 1000 feet its nearly impossible to find any stretch of road in any direction that resembles flat.

 

[edatoakrun]

temperature i can reproduce since it will be warm but the elevation will be a challenge. its mostly under 300 feet around here and when you do get over 1000 feet its nearly impossible to find any stretch of road in any direction that resembles flat.

Tony states each 1,000 ft. of altitude increases range by ~1.5%, on his chart.

I think the toughest significant variable to eliminate in duplicating conditions for a range test might be battery temperature at completion of charge. That's a tough one, unless you have a location with a ~constant temperature where you can park for many hours to "soak" your pack, just before completing your charge to "100%".

 

[GRA]

Found a couple photos:

At dawn, just before takeoff:

Did they do a Le Mans start? :lol:

 

[TonyWilliams]

unless you have a location with a ~constant temperature where you can park for many hours to "soak" your pack, just before completing your charge to "100%".

Yes, go beck and read the protocol. Charge, and sit in the same outside (not in a garage) ambient temps for a minimum of 4 hours (we were WELL over 4 hours).

Unless you're trying to correct for charging temperature... We didn't, but it was Phoenix in the early to late evening for every car that charged. Every car had six temp bars, of course. There isn't a smoking gun here, and any small differences will have minuscule overall range effects.

 

[kolmstead]

So the 4-bar car did 59/84, or 70% of new car range. Four bars would be 33.75% capacity lost, or 66.25% remaining. That's pretty good agreement with the car's actual range during the test.

Kind of squelches any hope of a simple instrumentation error...

 

[evnow]

temperature i can reproduce since it will be warm but the elevation will be a challenge. its mostly under 300 feet around here and when you do get over 1000 feet its nearly impossible to find any stretch of road in any direction that resembles flat.

Tony states each 1,000 ft. of altitude increases range by ~1.5%, on his chart.

That is for flat road. All our flat roads are close to the lakes (and thus mostly sea level). Lots of altitude variations kill range.

 

[edatoakrun]

unless you have a location with a ~constant temperature where you can park for many hours to "soak" your pack, just before completing your charge to "100%".

Yes, go beck and read the protocol. Charge, and sit in the same outside (not in a garage) ambient temps for a minimum of 4 hours (we were WELL over 4 hours).

Unless you're trying to correct for charging temperature... We didn't, but it was Phoenix in the early to late evening for every car that charged. Every car had six temp bars, of course. There isn't a smoking gun here, and any small differences will have minuscule overall range effects.

Yes, I think you should normalize charging temperature, since it is a varible that we really don't know how to correct for.

Not a "smoking gun", but a significant and avoidable source of inaccuracy, IMO.

I guess it depends on what range effects you consider "miniscule"(sp). Do you disagree with the opinion I posted last night?

...If they all had 6 bars on the battery temp gauge, I doubt you could have had more than ~20 F variation in battery temperatures at the times the charges were completed.

No one, AFAIK, has accurately calculated how much more capacity the batteries have (assuming the BMS does not intervene at some higher temperature) when the battery temperature is increased this amount, but I think most would say this is probably no more than 2% to 3%. Not huge, but probably quit a bit more significant than the accuracy caused by the variable levels your windows are open while you drive, or for that matter, whether your tires had 36 or 40 lbs of pressure.

A simple way of avoiding most of this inaccuracy in future "mass" tests might be to charge the entire "fleet" to anywhere from 80% to 95%, let the temperature normalize to near ambient (overnight, in your situation) and top them off just before the test.

 

[edatoakrun]

temperature i can reproduce since it will be warm but the elevation will be a challenge. its mostly under 300 feet around here and when you do get over 1000 feet its nearly impossible to find any stretch of road in any direction that resembles flat.

Tony states each 1,000 ft. of altitude increases range by ~1.5%, on his chart.

That is for flat road. All our flat roads are close to the lakes (and thus mostly sea level). Lots of altitude variations kill range.

So drive the flat see level routes. What's the problem?

Altitude doesn't "kill" range, though the effect is very significant on roads that require a lot of regen, to reduce your speed to the more efficient lower range required to rack up lots of miles. On mild ascents and descents, those that do not require regen or friction braking, the ascent energy is 100% recovered in the subsequent descent, though there is probably still a small loss of efficiency due to the more variable kW use, than on a otherwise comparable level route.

I've done all my "100%" to VLBW range tests of ~92 ~113 miles on the same route, with between ~5,500 to ~6,000 ft of ascent and descent, depending on miles driven.

After speed, the temperature of charging and driving has been my greatest variable, and the separate effects of both are very difficult to differentiate.

http://www.mynissanleaf.com/viewtopic.php?f=31&t=9064" onclick="window.open(this.href);return false;

There are errors in Tony's range chart. His assessment of the effects of ascents and descents being the most significant.

 

[TonyWilliams]

There are errors in Tony's range chart. His assessment of the effects of ascents and descents being the most significant.

Well, why don't you once again post this "stuff" on the appropriate thread, with your "perfect" regen data that fits in one line on a chart.

I'll probably ignore it, like normal, since as I've explained, and I'm confident you know, regen at 100% is near zero, hot and cold reduces regen, anything below 100% has variable values, depending on how fast the driver compresses the brake pedal (too fast REDUCES regen), and there are other variables.

You just whip out your simple answer.... Over there... On the other thread.

 

[KJD]

There are errors in Tony's range chart. His assessment of the effects of ascents and descents being the most significant.

In the range testing I have done, I have found Tony's chart to be pretty dang close. If you do not like his chart maybe you should write and publish your own chart.

You also seem to have a lot to say about the AZ testing the last couple of days, maybe you should find 10 or 12 cars and run your own test while you are at. Publish the results and let the world compare.

The more data we have the better.

 

[SierraQ]

Not a "smoking gun", but a significant and avoidable source of inaccuracy, IMO.

I guess it depends on what range effects you consider "miniscule"(sp). Do you disagree with the opinion I posted last night?

...If they all had 6 bars on the battery temp gauge, I doubt you could have had more than ~20 F variation in battery temperatures at the times the charges were completed.

No one, AFAIK, has accurately calculated how much more capacity the batteries have (assuming the BMS does not intervene at some higher temperature) when the battery temperature is increased this amount, but I think most would say this is probably no more than 2% to 3%. Not huge, but probably quit a bit more significant than the accuracy caused by the variable levels your windows are open while you drive, or for that matter, whether your tires had 36 or 40 lbs of pressure.

A simple way of avoiding most of this inaccuracy in future "mass" tests might be to charge the entire "fleet" to anywhere from 80% to 95%, let the temperature normalize to near ambient (overnight, in your situation) and top them off just before the test.

You know.... 2% of 80ish miles max range is.... wait for it... 1.6 miles!

1.6 miles is significant? When we are seeing overall ranges between 50 and 80 miles or so?

Tony, you know what? You also forgot to make sure the wind was consistently 6MPH from 5 degrees East of North by altering the route dynamically throughout the morning to compensate. Dang! How could you have missed that?

edatoakrun, with respect, enough of this. You missed your opportunity to comment on the particulars during the 1.5 weeks that Tony had his proposal out and during which the rest of us made contributions to it. It's a little late for doing so now. He covered far more variables than most of us would have even considered I think.

 

[TonyWilliams]

2:44am, just 25 minutes before I launched my car, "Black782", on the test course. Five of us stayed up all night, and one of those pictured doesn't even own a LEAF anymore!

Packing up to go home:

My car is loaded:

Off to brunch, then almost a 400 mile drive home:

 

[SierraQ]

2:44am, just 25 minutes before I launched my car, "Black782", on the test course. Five of us stayed up all night, and one of those pictured doesn't even own a LEAF anymore!

Who is who?