DC Rapid Charging - sort of a quiz question

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Gif

Well-known member
Joined
Jun 6, 2016
Messages
237
Location
Bottom right hand corner of Wales
Just wondering if I've missed this somewhere as I can't recall having read it on the forum or in the manual.

So I pull into a rapid charging facility with 8% SoC and plug in an operational DC Rapid CCS charger and commence charging. 32 mins later I return to my car.

What SoC would I expect to have (approximately) ? :ugeek:
 
Note that the fast charger cuts off after 30 min. The SOC will depend on how large your battery is. For 2017 cars with the larger battery you'll get up around 75%.
 
......so, with an 8% starting state of charge you should be able to get up past 80% even with 90ah battery on the 2017. More on the 60ah 2014-16.
 
Okay, you kinda knew there had to be a reason for me asking.

I thought the same. It's the 2017 94ah battery but I thought at 43kw minimum I would get to around the 80% mark.

I put the car on charge on a rapid last week. It got to 47%. The maths just don't compute so I queried it with the company who run the charger and send the bills (Ecotricity aka Electric Highway).

My car is working fine. It charges as it should. Had it on my 7kw charger at home, an AC 11kw charger on Sunday and I've done DC a few weeks ago from 17% to 90% in 30 mins. All the maths of those work out.

The reply came today. Apparently as my SoC was so low, in order to protect the battery, the charger reduced the power it was feeding in. This may or may not have been for the full period depending on when it decided the battery was able to take the full charge rate. This is why it only got to 47%.

Now I'm wondering if that sounds to you like the same pile of horse doodoo that it sounds like to me.

If you do the maths, it sounds like the charger was running at half power.

The reason I wrote querying it was I object to being charged the full amount for half of what I purchased.

Any comments welcome to support or shoot down their story :roll:
 
I have yet to try the CCS input I have on my car, mostly because there are so few around, and I just haven't needed it to try. I guess I should check it at least once before the warranty runs out.

The charge rate will somewhat depend on how warm the battery is when you attach it to anything to recharge it. The ambient temperature can make a difference, too. If the CCS unit itself was overheated (a recent user?) or not running at full capacity (a bad module?), it wouldn't have the full output available. On some, it shares the output, and cannot give multiple ports the full output (say someone else was charging at the same time?).
 
It was a warm day and being empty after 130 miles or so, probably meant the battery was warm too. This wasn't something I had built into my charging thought process though so need to factor in earlier or longer charges for any given route potentially.

CCS was all focussed on the i3. I have a feeling it was just a bad one and I'm being strung along.

A few weeks back I'd burned through 60% of the battery on a pretty hilly drive then some motorway. Attached it to a similar Rapid and it went straight from 17% to 90% in 30 minutes without so much as a blink.
 
Given the information you have provided, I would conclude the same as you: an impaired EVSE .
Did you really get 130 miles out of your i3 before it hit 8%? Have you ever gotten that much range before?
 
I put my 2017 on a fast charger, starting around 8-10% and it charged up to around 75% in 30 min.

Also, the guess-o-meter said around 130 miles but I actually got around 108 before the REx came on.
 
Yes, it was on A roads in warm day non stop mostly 40-60mph. I hit 117 miles with 20% remaining when I started looking for the first charger but the first two I found were occupied and the duff one was the third I found.

Towards the end of the first stretch of the journey before I shut down, I saw the equivalent of a 150 mile range for the first time.
 
Not a criticism as much as an observation that we don't have enough information. Key to my understanding:
  • What did the car ask for?
  • What did the EVSE reply with?
We can speculate about reasons why the car might not have requested a full charge but without metrics, we're flying blind.

Also, even a fully functioning EVSE may have received a signal from 'other sources' that limited its ability to provide a full charge. In a perfect world, we would know the voltage and current provided backed up by any 'pilot' signal to the car letting it know what the EVSE is capable of providing.

Please understand, I'm not faulting the owner or EVSE operator. Rather, without metrics, we're speculating.

Bob Wilson
 
Appreciate that Bob.

The point of asking was that I wasn't aware of circumstances where the car would ask for less power than was available (other than at the full end of the charge cycle) and replies I've got here and elsewhere show many examples of cars charging flat out from as low as 6% SoC.

The unit was a 50kw Rapid DC on CCS and I therefore expected it to deliver accordingly. It appears it didn't.

What I am trying to understand is whether the provider's information has any merit and should I be thinking of more regular charging stops on warm days with long journeys or is that a complete red herring.

Chris
 
A warm day in Wales would be a mild day in many southwest U.S. locations where E.V.'s flourish and reports of slower than expected DC fast charging are rare. The i3's battery pack cooling system should totally prevent heat-related slow charges in milder climates like in Wales. The charger itself could overheat, but in a milder climate, that would almost certainly be due to a fault.

Battery pack protection occurs at high, not low charge levels (at least according to the charging power vs. charge level charts I've seen). So that excuse seems bogus.
 
A hot battery should not be rapidly charged. The i3's logic won't let it happen. Charging does create heat, and the faster and longer you do that, the more heat is generated. Rapid or sustained high charge and discharge rates warms the battery pack.

Even if the CCS unit is in the high 90% efficiency range, if it has 50Kw output, it will be making some serious heat! They, like the internal components in the car, must manage their temperature. Assuming the CCS unit's cooling fans and filters are not compromised, depending on how hot it is, it just may end up overheating and reducing its output. THrow a solar load on it, that can just complicate the issue. Whether the thing had just finished a charging cycle on someone else when you arrive, could be a factor verses it sitting there idle for hours.

Much higher current rates are coming, and that will just make it even harder. Newer battery tech seems to have less internal resistance, so that bodes well since it won't create as much heat. THe future looks more promising when it all starts to come together. Ideally, you'd draw power from the electric roadway, and never need to stop and recharge the vehicle. That too, may happen outside of test tracks.
 
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