Blink end-of-charge demand curve, and power used by A/C

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Coffee_Slurry

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Joined
Sep 13, 2010
Messages
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Broken Arrow, OK
For anyone curious, this is a plot of power demanded by the Blink EVSE after a long charge.

After the charge was completed, I initiated the remote Climate Control, which likely ran the A/C for a short while. I was surprised at the amount of power consumed during Climate Control.

evse-with-climate-control.png
 
I have found that if I have charged to 80%, then later request the climate control from CarWings, it sometimes (but not always) then charges to 100%.

Was your first charge an 80% or a 100% charge?

If it was 80%, I'd lay odds that all that juice was actually going to the battery, not the AC.
 
This was a 100% charge. (I've never used the 80% charge option.)

I've found that even with a recent 100% charge, reconnecting the Leaf & Blink will start a fresh charge cycle that consumes quite a bit of power before determining the battery is, again, fully charged. (This happens whenever the Blink hits Midnight on one of the All Day schedules, thanks to a bug.)

This data comes from the ANSI optical data port on SDG&E's GE utility meter.

I take this data to be 'absolute' in that it is, exactly, what I will see on my power bill.
The meter runs 1.4% higher (in kWh) than the number reported on the Blink Network Dashboard.

The duration of the 'trickle' consumption at the end seems to vary. I've seen cycles with none at all -- just a straight drop to zero at the end. I don't know what is responsible for this.
evse-2.png
 
Can you show (with no climate control) the graph for:

1. a normal 80% charge, including at least two hours after the end-of-charge, looking for Equalization being done.

3. restart the 80% charge on an already 80%-full LEAF

3. charge to 100%, plus 2 hours, again watching for Equalization.

4. restrart a 100% charge on an already 100%-charged LEAF

5. start an 80% charge on an already 100% full LEAF

Thanks.

Will you please share exactly what hardware and software (and where obtained, model/version numbers, cost) you need/use to gather and graph this data?
I would like to try it.
PM if you do not want to post,
but I think many would be interested is this already-tested data-capture "package".
 
so average about 1.2kw to cool down the car and then 0.4kw to keep it cool?.. I assume the car was in a garage.. what was the ambient temperature?

Its a full size AC, should be ok in full Texas heat.

I would love to know what the pack voltage is after that cell balancing session at the end.
 
What I've seen is charges of about 0.05kwh after 80% (or 100%) charge completes - once or twice after a couple of hours. Do you also see that ? I've assumed this to be during cell balancing.

Also, the utility meter you are using is exclusively for Blink, right ?
 
its too bad that we dont have the option to warm the cabin during winter when charging instead of just wasting the excess heat. wonder if its too late to make any "winter package" suggestions?
 
DaveinOlyWA said:
its too bad that we dont have the option to warm the cabin during winter when charging instead of just wasting the excess heat. wonder if its too late to make any "winter package" suggestions?
Dave, I don't have my car yet, but I thought that the very thing you're asking for is already available in every LEAF, unless I'm not understanding what you mean by "wasting the excess heat."

Glenn
 
Glenn said:
DaveinOlyWA said:
its too bad that we dont have the option to warm the cabin during winter when charging instead of just wasting the excess heat. wonder if its too late to make any "winter package" suggestions?
Dave, I don't have my car yet, but I thought that the very thing you're asking for is already available in every LEAF, unless I'm not understanding what you mean by "wasting the excess heat."

Glenn

nope Glenn, afraid not. the excess heat is dissipated by a water/radiator system which DOES not lend to cabin heat. there is a pre-heat option but it uses ummm..."fresh" electricity to run. granted i have used it twice and its very efficient. only takes about 5-7 minutes (for all of you who report preheating for 20 mins) to completely clear a very frosted over Leaf.

i guess for viability, we would have to examine power consumption between the water pump for the cooling system and a low speed fan into the interior?
 
From what I can tell, Charging dissipates very little heat.
The hood isn't even warm. The batteries don't even rise "one bar" in the temperature graph on a full charge. It wouldn't be worth any added complexity to try to scavenge the charging heat into the cabin.

I haven't seen the car ever come back for a "second helping" after the 100% charge is complete. It makes a loud 'thunk' any time the EVSE switches the relay, so I think I would notice. I haven't seen it on the power charts either. The post-absorption trickle charge duration and shape does seem to vary, but it doesn't seem to disconnect the relay and restart. Have you seen this?

To confirm: Yes, the Blink EVSE is the one and only device downstream of this utility meter. There is no other load, and the load rests at zero when the Blink is unplugged.

I'll experiment with 80% someday soon, but for now, I want the extra range reserve that I can only get with 100%.

I had to abandon the Blink's internal timer as well -- too buggy. So I'm on the LEAF's internal timer now. This means I get the short-term 'clunk' on connection, as the Leaf tests the juice.
 
GroundLoop said:
I haven't seen the car ever come back for a "second helping" after the 100% charge is complete. It makes a loud 'thunk' any time the EVSE switches the relay, so I think I would notice. I haven't seen it on the power charts either. The post-absorption trickle charge duration and shape does seem to vary, but it doesn't seem to disconnect the relay and restart. Have you seen this?
Yes.

For eg. 22nd night at 7:51 PM I got one charge complete message. Two more messages in the morning at 5:38 AM and 7:14 AM. The kwh used on 23rd morning was slightly more than what Blink showed on 22nd night - by 0.05 kwh or so.

I don't have a separate meter - but I'll probably get the optical meter reading one of these days. Which one do you have ?
 
evnow -- I believe that your observation is because of a bug or crash in the Blink, and not intentional Leaf behavior.

When the Blink crashes, it may cycle power to the car, which causes the Leaf to do "another charge". You get the same start/end notifications in this event, as if you had disconnected and reconnected the J1772 plug.

These "bonus" charges from the Blink allow the Leaf to go through a brief but full charge, reaching the endpoint and doing some amount of post-charge trickle off.

For example, when I had my Blink set to 12:00-12:00 for Sat & Sun, at each midnight it would cycle power briefly and start the LEAF charging again.

Once I changed the Blink to "charge always" and used the timer in the Leaf instead, I did not see any more of these "brief charge" events.

I also notice that the Blink crashes quite often -- it frequently goes through boot-up screen during charge, or after.

Here's the thread discussing the optical port adapter:
http://www.mynissanleaf.com/viewtopic.php?f=24&t=403&p=28127&hilit=tespro
 
GroundLoop said:
evnow -- I believe that your observation is because of a bug or crash in the Blink, and not intentional Leaf behavior.

When the Blink crashes, it may cycle power to the car, which causes the Leaf to do "another charge". You get the same start/end notifications in this event, as if you had disconnected and reconnected the J1772 plug.
I haven't had any crashes of Blink lately. BTW, I charge to 80%.

My cable is plugged in from the time I come home to the time I leave i.e. evening till morning. Blink is set to charge all the time and Leaf charges from 7 PM to 10 AM.
 
GroundLoop said:
Here's the thread discussing the optical port adapter:
http://www.mynissanleaf.com/viewtopic.php?f=24&t=403&p=28127&hilit=tespro
Interesting ... Black&Drecker has one. Below $30 at Amazon. No link to PC, though. Just a handheld meter.

http://www.amazon.com/Black-Decker-EM100B-Energy-Monitor/dp/B001ELJKLE/ref=sr_1_3?ie=UTF8&s=hi&qid=1306286117&sr=1-3

2a01c060ada0d01340a20210.L.jpg
 
Umm.. that's not a data adapter. That's a stand-alone kWh counter. It either watches the spinning rotor with the black mark, or the IR pulse (emitter) that approximates the same. Fine and all, but it's a different deal than the precise values from the meter.

Guys -- the ANSI port on the modern meters is a full-fledged RS-232 *DATA* port. You send the meter queries, it sends responses. This is how the meter reader reads out the monthly usage, sets the programming, and so on.
 
So here's a charge to 80%.. doesn't look much different, and I don't see any after-charge events. Granted, I only waited an hour.. do they usually come much later?

I want to get on with the 100% charge..

80pct-charge.png
 
GroundLoop said:
So here's a charge to 80%.. doesn't look much different, and I don't see any after-charge events. Granted, I only waited an hour.. do they usually come much later?

Probably no cell balancing stage if you only charge to 80%, and that makes sense, its one of the reasons its a recommended way to charge.
 
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