Saturday, April 9, 2016

Fast Charge Profiles

**Reader Note**
This will be a different kind of entry as it will be a work in progress for at least the next few weeks. I am posting initial reports because I know some of you check my blog randomly for new posts.  If anyone desires the CSV files the charts were created from post here with your email (probably not a good idea) or PM me at MNL or Facebook.

**Note; Costs consider the first 30 mins on QCs free due to NCTC**

4/8/16   Blink at Tahoma Market.  OAT  72ยบ.   GIDs  46-213.     kwh LEAF Spy; 12.08  Blink; 14.50  cost $.02   Starting KW; 46,  ending KW  12.2   time "about 29 mins 30 seconds but due to the .02 charge, "someone" thought it was greater than 30 mins...

kwh on 30 minute charge
 Notes; For the first time ever (granted, its not something I normally look at) I noticed a much lower charge efficiency. with 12.08 kwh going thru LEAF Spy but Blink claiming I received 14.50 kwh means and efficiency of 83%.  I have tracked this machine before and it was always over 90%.  I did not hear the LEAF's fans running (they were pretty loud on my 2011) but then again, I was at a truck stop a few hundred feet from I-5 so not the quietest area in town.

Conclusions; Blink gets a lot of complaints but I have had very little trouble with them overall. I can't help but wonder when their clock starts as I specifically wanted to stop before the 30 mins was up but apparently a 20 second cushion was not big enough. I will pay a LOT more attention to when I need to start the stopwatch next time.

3/18/16  NRG Tacoma Mall.  Several sessions here.

NRG's stations won't charge more than about 40 KW due to its maximum limit of 100 amps so wasn't expecting super big numbers and since their billing is by the minute its obvious they know how to butter the bread! This session had no major surprises.  I started the charge at 68 GIDs and it went to 100 amps giving me just under  38 KW but then started dropping at 74 GIDs. This was not a gradual drop, more of a tiered drop as it settled to 90 amps.  From this point it slowly dropped until the finish of the session which lasted 29 mins 12 seconds. (I wasn't sure whether the station would shut off by itself after my 30 min free time and wasn't willing to pay anything)   finishing with GID count 224 with final charging speed roughly 10.5 KW.  So, not the best, but ok, I suppose.


Due to me having a light schedule at work, I was naturally the first one work would call for any last minute needs (My job has several a day it seems...)  But I ended up having to criss cross the region a few times so stopped at NRG again which is just over a mile from work. But I got a hot customer that was very time sensitive so had to get a charge and fast and besides, I was so low I really couldn't go home either so I plugged in at 30 GIDs and...

WTF??? I had half as much charge from the earlier session (I was only at 6 TBs) but I was charging at half the speed??  I had two destinations to get to, one North the other East.  Now I did not have enough to make it to both without charging to make it home.  When was the last time anyone here ended up with a faster charging rate at the end of the session?? I basically charged for 30 mins at a fast charger and then left with FIFTY FOUR PERCENT STATE OF CHARGE!!  

Now why was this happening?  Heat wasn't it. Nowhere near that point. The only thing I could figure is there was an i3 on the L2. Now it would be drawing 7.2KW which is a pretty hefty bunch so could it be possible, the power is split 50-50?  Wow... I guess I have seen dumber decisions... I think...

Finally I get back to charging and no longer interested in getting my free 30 mins. I was pretty tired of this place by now so only wanted to get what I needed and go... that is IF I could do it in 30 mins or less. By now it was after 7 PM and I was lucky my last appointment of the day had no real time frame.  But as luck would have it, I was back to the 100 amps again!! And because I was at 136 GIDs (yes MORE than 100 GIDs higher than my earlier session) I was charging just under 40 KW!   I was gone in 21 minutes!

AV 3/19/16;

Despite getting an email confirmation within 2 minutes of completing my EZ Charge registration on their site; the card was not being recognized at the station. I tried both Centralia and Tumwater with the same results. Finally, I called and got two completely different responses. One time, I called and the lady verified my name and started the charge for me. The other lady completely shut down after she heard I was using an EZ Charge card and refused to help me. Now the card works fine and the "bleeding edge" is starting to heal a bit.

This session started at 79 GIDs and lasted 27 mins ending with 217 GIDs. This was the most powerful session so far starting at 125 amps and 46.5 KW. This lasted almost 3 minutes! (167 seconds).  But then again, this makes sense. Unlike Blink or NRG,  AV has an "all you can eat" $19.99 billing system there is no reason for them to throttle back the speed, right?

NRG   3/24/16;

This session was designed to look at what parameters we would want to switch to L2 in consideration of our fellow "Electronite".  Again, very surprising results.  I started the charge at 157 GIDs and 28 KW to finish it 27 minutes later at 228 GIDs and 4.7 KW.  I am posting this to prove it happened. I can only hope its some sort of anomaly.

Blink 3/25/16;

Well NRG was just really disappointing so I decided it was time to try Blink.

Here I started the charge at 64 GIDs and immediately saw 46 KW! NICE!!! Granted it only lasted a short time so guessing it was more of a battery check than anything but the end results were the significant part. After 30 mins, I was at 221 GIDs but still absorbing  11.6 KW (Keep in mind this is LEAF Spy reading so this is AFTER efficiency losses).  In fact, it took just over 44 minutes before I slowed down to the same 4.7 KW charging speed of the NRG but at 243 GIDs!

Blink 3/27/16;
Start 60 GIDs, 45 KW.  End  217 GIDs,  12.2 GIDs, charging duration  28 mins, 10 seconds.


  1. Chargers that provide more power to one car alone than to two charging together are pretty common. Even Tesla SuperCharger stations do that. It is also pretty common to split the power in half, even if both cars can't use half. Easier that way.

    1. Never seen any other fast charger do this and there are SEVERAL that come in pairs; one fast charger, one L2. I do plan to scout for an opportunity to check out the fast charge speed the next time I see someone plugged into the L2

  2. Based on your experience, is it safe to say that in 30mins, I should expect around 10kWh? I'm trying to see if it's feasible to do a trip to Great Wolf Lodge from Bellevue area, charging once at Tumwater for 30mins on the way there, and again on the way back.

    I was hoping that a 30min charge will get closer to 15-20kWh, but I guess that may be asking for too much

    1. Its going to depend on how high your SOC is when you start. Keep in mind; a full LEAF only has 22 Kwh to begin with so an 80% charge is going to be in the 16ish neighborhood so if you start charging with 2-4 kwh already in the tank, don't expect to get more than about 12-13 kwh at the most.

      Now if you have the larger 30 kwh pack, the fast charge profile is steeper which means longer time charging near the full speed of the station so 15 kwh is very possible. In fact, I have seen reports of people getting in the 18 kwh neighborhood

    2. That's good to hear. Yes, I have the 30kWh pack, and it'd be great if I can make the 165miles RT with just a single fast charge at Centralia, but I'll live with two if I can't make the 82 miles one way trip keeping up with traffic.

    3. 30 kwh pack is a HUGE difference that goes far beyond the extra 6 kwh. The charging profile is just one part of it. I might consider stopping in Tacoma on the way home but with the extra range, you will be pretty close.

      FYI; some have had success getting the Lodge to allow them to plug in. Last check, the only real plug that was easily accessible was near the customer sign in. Can't guarantee they will help you but I would take an extra 50' ext cord with your EVSE just in case