GM Volt Forum banner

1 - 15 of 15 Posts

·
Registered
Joined
·
155 Posts
Discussion Starter · #1 ·
I'm playing around with my DashDAQ and I like many are curious about pre-conditioning (remote start), charging and really any number of other things on the car really. Since it's getting cold and there are alot of questions in the area of pre-conditioning in particular I thought I'd post a graph of some key measurments. See the attached chart.

The chart runs about 23 minutes. Immediately after starting the logging I did a remote start. I let it continue for 10 minutes then 2 minutes later did the second one.

Hopefully I'll be able to build some more readable graphs since the one that Logworks produced is not easily decipherable if i were to just toss it up here. I'll try to call out some references below so you can interpret the values.

  • You can see on the chart that SOC drops ever so slightly from about 86% to 85.7% during the first one. It fully recovers and then some to 86.3% on during the second.
  • The next line down is the current being supplied to the HV system by the charger. It start out at 7.5A, peaks at 7.7 and settles in at 7.65A during the last part of the first cycle.
  • The next line is the current being drawn at the J1772 plug. Next down is the ESS inlet temperature which I believe to be the temp at the inlet that pushes the 'coolant' that either cools or warms the HV Battery. The temp is 59F during the whole first cycle and peaks at 64F during the second.
  • The next one is the HV battery temp which remains at 57F barring some odd spikes which are probably extraneous(?).
  • Next the ambient air temp in my garage. It starts out at 52F, goes to 54F in the first cycle then peaks at 59F in the second. Odd really as the only thing that would be impacting this would be the car itself.
  • Th next line is the power requested by the cabin climate control which remains at 2.5KW throughout the cycles. I would assume but do not know that this is really a maximum power requested.
  • The last line is the purple one which is the APM current. It spikes to 71A upon first startup and finishes the first cycle at 32A. It finishes the second at 23A.


I just thought I'd toss this up here in case it was interesting for anyone else. The site wants to scale the image down to where it's not readable so I've hosted a full resolution one here.
 

Attachments

·
Registered
Joined
·
3,165 Posts
Cool- hot data. and thanks.

I presume this is 240v. Also were you already charging when it started (86SOC suggests if it was able to charge it would be.. ) If it was already charging then the battery should be pretty warm from that so it may not represent a early am pre-condition.
That might also explain the difference with Scott's post on the TED data that suggests is still needs charging, even on 240v after the cycle ends.
(Scott's data at
http://gm-volt.com/forum/showthread...f-two-10-minute-preconditions-on-220v&p=95430)
 

·
Registered
Joined
·
155 Posts
Discussion Starter · #3 ·
Cool- hot data. and thanks.

I presume this is 240v. Also were you already charging when it started (86SOC suggests if it was able to charge it would be.. ) If it was already charging then the battery should be pretty warm from that so it may not represent a early am pre-condition.
That might also explain the difference with Scott's post on the TED data that suggests is still needs charging, even on 240v after the cycle ends.
(Scott's data at
http://gm-volt.com/forum/showthread...f-two-10-minute-preconditions-on-220v&p=95430)


I knew I'd forget to provide some context on something :). Yes, this is 240V but charging completed probably 12 hours previous to this. I had done one remote start about an hour before this as I started playing around looking at data. The cabin climate was set to Auto, Eco and 75F. The car had been parked in the garage for the last 18 hours or so.

I can't explain any discrepancies because if I did at this point I'd be completely guessing. :) I'm just learning myself so I just posted the data for all to see. As I have more time I'll try to do some more controlled experiments. Also when the new house is complete in 6 or 8 weeks or so I'll have Ted 5000 data as well so I should be able to take both data sources, put them into Excel and lay them on top of each other.
 

·
Registered
Joined
·
109 Posts
Really interesting start to your data collecting. it will be nice to get a clearer picture of what effect pre-conditioning has on the soc, as the weather gets really cold...my car is outside for the first winter.

Looking forward to more data, and analysis!
 

·
Registered
Joined
·
155 Posts
Discussion Starter · #5 ·
Thanks. This is a fun tool to have but I can see I'm going to come up more questions than answers for awhile. I was thinking about throwing the 120V EVSE on it and repeating the test just for fun. On that one I could also put the Kill-a-Watt on in the mix to check some of the data at another point.

Order placed -Olympic White
Are all the colors named differently for Canadian models?
 

·
Registered
Joined
·
109 Posts
Are all the colors named differently for Canadian models?
At the time I ordered they called it Olympic White, but now they seem to call it Summit White. My understanding is that it's the same paint code, GAZ, just called by different names sometimes.
 

·
Registered
Joined
·
3,165 Posts
Thanks for the update.. so this means the SOC being reported by the dashdaq is probably the actual absolute SOC (not the SOC reported on the iphone app) as 85-86 SOC on the dashdaq is fully charged.

Also looking back at the original post it seems odd that the battery temp would be down at 57F.. I though they tried to keep it between 68 and 72F at all times. Any chance there is a missing temp offset there?

The Ambient air temp has an odd gap beween 10:20 and 12?
 

·
Registered
Joined
·
273 Posts
Unscientific observation:

My2011 Volt with 240V charger


WattVision whole-house electicity reading


11:29am reading 1066 watts
begin remote start #1
reading jumps to 4433 watts
11:42am reading drops back to 1062 watts


11:49am reading 1062 watts
begin remote start #2
reading jumps to 4385
11:59am reading drops to 1245 watts
 

·
Registered
Joined
·
155 Posts
Discussion Starter · #9 ·
I re-ran this today a bit more carefully and with longer gaps after the starts to see what happens. Long story short is that is is in line with what Scott and eplantz see - the car does take a bit to recover after each charge though just to move the SOC of the HV Battery up a few tenths of a percent. I don't have time to post the data right now but will get to it later.

TBoult - I watched today and when the car is off it looks like ambient temp gets reported "occasionally". It's odd but what happens is that data is no longer constant and it looks like its NULL. The bottom of the scale for that measure is -40F so that seems to be whats inferred. I need to look at the timing but when the car is off once it a while it reports the actual ambient then it goes back to NULL.
 

·
Registered
Joined
·
2,632 Posts
so this means the SOC being reported by the dashdaq is probably the actual absolute SOC (not the SOC reported on the iphone app) as 85-86 SOC on the dashdaq is fully charged. [snip]

The Ambient air temp has an odd gap beween 10:20 and 12?
The DD has several ways to measure battery SOC, most of which report roughly the same number which appears to be absolute SOC (I generally use the 1542 SOC VICM). Signal 1550 is SOC Gauge Position, which maps to the DIC display battery gauge (that is, it goes from 0-100 for the SOC VICM's ~22-87).

I haven't tried using the DD while my Volt is off (I was surprised to see Pauldon getting numbers there). The OBD port mostly shuts down for me when I turn the car off. Pauldon, are you saying it wakes up occasionally, and that's how you're getting your "car off" measurements? Does the OBD bus turn off explain the data gaps?
 

·
Registered
Joined
·
155 Posts
Discussion Starter · #11 ·
To be clear I have not tried to get any data while the car is both unplugged AND turned off so I can't say what I'd see there. I'd say most cars don't have anything to do when they are off but the Volt on the other hand, at least while plugged in, needs to keep an eye on SOC to know if it should be charging as well as HV battery temp to know if it gets too cold or hot so I can see why there might be data moving even while the car is off.

What I've seen so far is that yes, some data is available while the car is off. Certainly the charging data and SOC as I 've confirmed by watching today after a remote start takes place. I was able to see it take another 6.5 minutes until the SOC hit 85.7 and the charger stopped drawing wall current. It's also become clear to me that this is the SOC that causes the charger to consider it's work done. It's consistently what the SOC is when I first measure it after the green light goes blinky and the number that seems to trigger the charger to stop supplying current.

When the car is off there is at least constant data available about the charger but things like ambient temp go away. The interesting thing is that at the exact moment when the charger stopped drawing wall current it seemed to 'wake up' something because the ambient temp became available again for 13 seconds. I can see it come back at other times even after the charger is off - it doesn't SEEM to be on a timer - but when it comes back it's ALWAYS for 13 seconds.
 

·
Registered
Joined
·
155 Posts
Discussion Starter · #12 · (Edited)
Ok. here is another chart. I've only started messing with Logworks and I couldn't make it do what I wanted and I know Excel well so thats what I used this time. The only problem is that Multi-Y charts are a PITA and it's late and I'm tired. Luckily most of the actual numbers are less important than the overall picture for this discussion so here you go.

See the unscaled image here.

This was 2 remote starts with an ambient garage temp of 54F. The car hadn't been driven in almost 48 hours and charging completed over 36 hours ago. It has been plugged in the entire time. The climate was set to Eco and 75 degrees.

I started then waited for it to time out, then waited to see how long it would take for the raw SOC to reach a level that triggered the blinking green light on the dash. The answer was 6.5 minutes after the first start completed and 85.7 is the magic "done" for the battery. I waited a few more minutes just to watch the numbers and saw nothing happening so did the second remote start 2.5 minutes later. The process repeated and the second time it took 4 minutes afterwards to recover. It's interesting to note, and I can't explain why, the SOC dropped only to 85.5 by the end of the first cycle, but 85.3 by the end of the next. Of course I have no idea what the true resolution or accuracy of the underlying measurement is. I'm merely using the DD to read what the car is telling me. It's entirely possible that the numbers are within a margin of error that makes them equivalent.

The good news it that we're talking about a very small hit to your range so just do the remote start, maybe two, then get in the car and drive. Of course I've not tested on Comfort yet or on 120V and you'll need someone in MN or Toronto to provide data on what this would look like if it were 15F outside. I'm in Seattle and it could be a decade or more before it gets that cold, though it has happened before.

In the end this chart shows what Scott and eplantz saw by looking at the current draw for their EVSE. Now we know that whats going on is that the car is trying to get back about .2 - .4% SOC. So Scotts advice is right on the money if what you want is the absolute maximum fill on your battery before hitting the road. Start, wait maybe 20 minutes in total. If you really want to make sure you are warm on your drive, repeat but this time you can get in and drive after 15. At least in my situation we seem to be talking about 100Wh or so and I'm not sure I care.

Though 2 days ago the car did switch to CS mode as I was moving the shift lever to park after returning home. :)

DoubleRemoteStartTake2.jpg
 

·
Registered
Joined
·
273 Posts
Observations on a cold day:

I have been using the VBS script developed by another member here:

http://gm-volt.com/forum/showthread.php?9967-Script-to-start-the-Volt

I set up a batch file to run on Windows that remote starts the car, waits 13 minutes and does the second remote start.

2011 Volt
240V charger
garage temp about 50F
outside temp 37F

I purposely began the 2 start procedure so there was enough time left before I entered the car to get back to a full charge.

The inside of the car felt warm (was 62F) and I had the climate control set to FANS ONLY, AUTO-RECIRC and FAN SPEED 2 clicks from off position.

Driving in 37F temp, I was getting an ACTUAL RANGE of 42 miles driving 45-50 mph most of the trip. The inside of the car warmed up a bit to 66F even with the climate control at FANS ONLY.
 

·
Registered
Joined
·
155 Posts
Discussion Starter · #14 ·
Those were the same temperature conditions I had this morning. I wish I could get that kind of range but significant elevation change is a reality on most of my trips where I live which seems to impact that - the trip back home is the killer. I need to budget at least 6mi on my range indicator for the last 1.7mi to my house. 5mi wont' be enough to make it, 7 will be and 6 might be. I do add 1.3% to the HV SOC when I leave my house in the morning though.

You can of course confirm you are back to a full charge by the light blinking on the dash after the pre-condition. Also with the climate set to fan only I believe the pre-condition happens at "comfort".
 

·
Registered
Joined
·
1,491 Posts
If you have time to kill, it would be cool to see this experiment for the 120V charger.
 
1 - 15 of 15 Posts
Top