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Fact check the Nissan salesman for me?

Posted: Tue Sep 11, 2018 11:00 am
by ptomblin
We bought a 2018 Leaf last night, picking it up tomorrow. The salesman said something I have trouble believing: he said that the 440V DC Quick Charge port is only for emergencies like if you completely run out of charge and have to be towed, because using it too often could damage the electronics. Is that for real?

Re: Fact check the Nissan salesman for me?

Posted: Tue Sep 11, 2018 11:20 am
by 2k1Toaster
ptomblin wrote:We bought a 2018 Leaf last night, picking it up tomorrow. The salesman said something I have trouble believing: he said that the 440V DC Quick Charge port is only for emergencies like if you completely run out of charge and have to be towed, because using it too often could damage the electronics. Is that for real?
Classic case of a little bit of knowledge being dangerous.

The DCQC CHAdeMO port is just a direct connection to the battery via a closely monitored DC bus versus feeding in AC and using the charger on board the car. In CHAdeMO's case, the charger is in the big metal box outside the car.

As a general rule, the more quickly you charge and discharge the battery the harder it is on the battery. This is true of discharging via heavy acceleration 80KW as well as quick charging at 50KW. The real factor is that when you do these high power energy transfers you are also creating heat. If it is hot outside and you're shoving 50KW into the battery it will get even hotter. That's the true enemy of the battery.

It is not just for emergencies. But if you don't need it, there's no reason to use it. It is for road tripping or topping off because you need a bunch of charge in 20 minutes and can't wait 3 hours. That's it.

Re: Fact check the Nissan salesman for me?

Posted: Tue Sep 11, 2018 1:08 pm
by LeftieBiker
Further, there is no harm in using it in cool or cold weather, as long as the battery temp "gauge" reads below the halfway point. Using it in frigid weather may not be a good idea if not needed.

Re: Fact check the Nissan salesman for me?

Posted: Tue Sep 11, 2018 1:12 pm
by alozzy
@ptomblin It mostly depends where you live...

In cooler climates, except on perhaps the hottest days of summer, you can safely use DCQC at high charging rates with minimal impact on the battery. I live in Vancouver, Canada so I don't hesitate to use DCQC when it's convenient or I'm in a hurry because the battery seldom gets hot. With the 2018 LEAF, the BMS limits charging rates considerably when the battery gets hot anyways.

Re: Fact check the Nissan salesman for me?

Posted: Tue Sep 11, 2018 4:28 pm
by webeleafowners
Your salesman is out to lunch. Use your DCFC whenever you need to charge, you know, fast. We use ours mostly for road trips...without hesitation, EVER.

Re: Fact check the Nissan salesman for me?

Posted: Tue Sep 11, 2018 5:48 pm
by LeftieBiker
webeleafowners wrote:Your salesman is out to lunch. Use your DCFC whenever you need to charge, you know, fast. We use ours mostly for road trips...without hesitation, EVER.
This "I do it all the time, so it's fine" category of advice can come back to bite the person being advised on the ass. Someone who bought their Leaf, or who leased but needs 90% of the capacity for the whole lease is going to be unhappy if they regularly charge with QC when the pack is already hot, going by the evidence so far.

Re: Fact check the Nissan salesman for me?

Posted: Wed Sep 12, 2018 7:01 am
by WetEV
LeftieBiker wrote:
webeleafowners wrote:Your salesman is out to lunch. Use your DCFC whenever you need to charge, you know, fast. We use ours mostly for road trips...without hesitation, EVER.
This "I do it all the time, so it's fine" category of advice can come back to bite the person being advised on the ass. Someone who bought their Leaf, or who leased but needs 90% of the capacity for the whole lease is going to be unhappy if they regularly charge with QC when the pack is already hot, going by the evidence so far.
Unhappy because of the slowed charging rate at higher pack temperatures? Perhaps, perhaps not. Depends on details.

The salesman is still out to lunch.