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Discussion Starter #1
I went for my first motorway drive in my Zoe Q210 on Saturday. 76 miles each way, in eco mode at the maximum allowed speed, mostly 58 MPH on the way there and 60 on the way back.

I plugged into a rapid charger as soon as I arrived, 43kW. The AC compressor came on as soon as I plugged in. With 16% charge when I plugged in, I was expecting the car to fully charge in under an hour. After all, the quoted 0 to 80% charge time at 43kW is 35 minutes. I went back 50 minutes after plugging in and the car was on 96%. It was on 99% when I unplugged it after 60 minutes.

21kW average charge rate from 16% to 96% is slower than I was expecting. What are the likely reasons the charge was fairly slow?
 

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I went for my first motorway drive in my Zoe Q210 on Saturday. 76 miles each way, in eco mode at the maximum allowed speed, mostly 58 MPH on the way there and 60 on the way back.

I plugged into a rapid charger as soon as I arrived, 43kW. The AC compressor came on as soon as I plugged in. With 16% charge when I plugged in, I was expecting the car to fully charge in under an hour. After all, the quoted 0 to 80% charge time at 43kW is 35 minutes. I went back 50 minutes after plugging in and the car was on 96%. It was on 99% when I unplugged it after 60 minutes.

21kW average charge rate from 16% to 96% is slower than I was expecting. What are the likely reasons the charge was fairly slow?
It'll be charge tapering. When a battery is empty it can charge really fast, but as the battery fills up the charge rate will slow right down. This is why rapid chargers usually only charge to 80%. The last 20% will take the same length of time again. Better to unplug at 80% and continue your journey if possible.
 

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It'll be charge tapering. When a battery is empty it can charge really fast, but as the battery fills up the charge rate will slow right down. This is why rapid chargers usually only charge to 80%. The last 20% will take the same length of time again. Better to unplug at 80% and continue your journey if possible.
Well... while the principle is correct, my old ZOE didn't used to taper significantly until it got into the 90-95% range and I suspect the new ZOE may be similar. So the key metric is how long it took to charge to, say, 90%.

In my experience of Ecotricity rapids, and following the principle of 'a bird in the hand', I used to charge to 99% and then move on.

My blogs:
ZOE Charging Curve (Ecotricity 43kW) - My Renault ZOE electric car
Charging curves - My Renault ZOE electric car
 

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The ZE40 charging tapers earlier than the 22kW battery Zoe did. Best I've had was 27 kWh in Ecotricity's allotted 45 mins.
 

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Well... while the principle is correct, my old ZOE didn't used to taper significantly until it got into the 90-95% range and I suspect the new ZOE may be similar. So the key metric is how long it took to charge to, say, 90%.

In my experience of Ecotricity rapids, and following the principle of 'a bird in the hand', I used to charge to 99% and then move on.

My blogs:
ZOE Charging Curve (Ecotricity 43kW) - My Renault ZOE electric car
Charging curves - My Renault ZOE electric car

Pre-BMS. Back in the old days you'd get to 90+% in 25minsto 99% and drive on 70±miles. And now you'll take 45+mins to get to 90% and still only get 70miles. But as I've so often read 90% is the new 99%, but those claimants never could explain why it took 20mins longer.
 

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Discussion Starter #6
I get that the charging rate tapers. It seems that my car tapered more than most. Would the battery have been too warm to accept the full charging rate? Ambient temperature was 16°C which is not hot, but the car had just done 75 miles non stop at 58 MPH, so the battery could have been quite warm.
 

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I get that the charging rate tapers. It seems that my car tapered more than most. Would the battery have been too warm to accept the full charging rate? Ambient temperature was 16°C which is not hot, but the car had just done 75 miles non stop at 58 MPH, so the battery could have been quite warm.
Driving at 58mph will not put much heat into your pack.. chances are it would be barely even at external ambient temp. Check with CanZE. If you were hoofing along at 70mph then you can assume your pack would be warmer than ambient.
 

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I only get 16.5 Kwh on a R110 in 45 min on a Ecotricity rapid, about 22 Kwh charging speed from 20% to 60%, wish I could get the CCS DC charging upgrade that the new ones will have next year :rolleyes:
 

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I only get 16.5 Kwh on a R110 in 45 min on a Ecotricity rapid, about 22 Kwh charging speed from 20% to 60%, wish I could get the CCS DC charging upgrade that the new ones will have next year :rolleyes:
Only? That sounds about bang on.... your car charges at a max of 22kw. Meaning in an hour from very low SOC you'll just about get 22kwh.

Don't hold out any hope of "upgrades", Renault don't give a toss about existing customers. Heck they barely care about new ones.
 

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Don't hold out any hope of "upgrades", Renault don't give a toss about existing customers. Heck they barely care about new ones.
Too true, remember the promise to offer pack upgrade from 22 to 40kWh, they even had a lot of owners names on a 'waiting list' mine included.
 

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Wonder how many 22kwh > 41kwh Zoe owners will switch to the CCS 50kwh model and feel the same buyers remorse they felt after the switch from 22 to 41. lol
 

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If you mean in respect of slower charge rate/earlier tapering, then yes I was disappointed as I maybe naively expected it to charge at a similar rate as my old Zoe, but I have no remorse as the times I need the rapid charge like trips down South it does the job very well.
 

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Discussion Starter #13 (Edited)
I did a test charge on a 22kW charger and took some graphs using CANze. The car even charged slowly on that. What's the reason the battery won't accept full power?

It was 3 degrees outside. The battery temp rose from 10 to 14 degrees during the charge. The available power was signalled at 20kW. Yet the car started off taking 15kW and dropped it to 11 over time. It went up a bit every time the battery temperature rose a degree, but then it went back to dropping again.

Is it battery temperature that is holding back the charge it will accept, or something else?
 

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Is it battery temperature that is holding back the charge it will accept, or something else?
Yes, its pack temperature, I'm sure @yoh-there mentioned mid 20 degrees was optimum temp.
 

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Very typical behavior. The jump up is indeed by temperature. The values we can pick from the battery controller are in full degrees only, so that kind of makes sense. The downward curve is by State of Charge: the fuller the battery, the less power it can take in.

The mid 20's is more pronounced for the ZE40 battery. The 22 kWh battery of the Q210 will happily take 40 kW when at 80% SOC and 40C battery temp :eek:

Here is the visualized model of what we use in the CanZE charge prediction model. Under the hood it does a bit of numerical integration and some raw assumptions about i.e. self heating.

Max Pwr
 

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Discussion Starter #16
Thank you, that's very enlightening. Best to charge when the battery is warm then.

So on Saturday when the AC compressor came on as soon as the charger was plugged in, I assume the battery was too hot at the start. It must have overcooled to take 50 minutes to get from 16% to 96%.
 

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Co-author of CanZE. Q210 nov 2013
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FWIW, in my experience the A/C compressor almost never comes on while charging. The battery fans do, a quite soft "rumble" near the rear wheels. If the big fan under the bonnet kicks in that is still not necessarily the A/C: it blows on two radiators, one from the climate system, and a smaller one from the water cooled electronics boxes and motor. If the slightly more rattling sounds kicks in, it's the A/C compressor. But, that can all easily been seen / verified in the Climate screen of CanZE, you can see the compressor RPM and the mode.

I've seen fans come on aggressively, especially on 43 kW chargers. It seems to cool preemptively. Actual active cooling seems to be more a thing when it is really hot outside. One hot summer night after a drive when I hooked up my slow 3 kW charger, it started it's quiet battery fans and even the compressor and front fan, but the latter on a very, very low setting. It was almost unnoticeable.
 
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