Is it possible for user to limit Chademo charge rate?

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Tbobz

New member
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Dec 28, 2019
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In a Clean Technica article by Dr. Holland that discusses tactics to deal with DCFC heat, the good doctor suggests to Nissan that they allow user to limit the charge rate. So, can only Nissan do this or is there a hack or a device that would accomplish this? I found a thread from years ago that touched on the notion but it seemed inconclusive. Thanks in advance an thanks to all whose contributions to this site have aided me in better using my Leaf.
 
Gen 1 Leafs definitely had no UI to limit it. I doubt gen 2's do. I guess if you want to limit the rate, just gen a 40 kWh w/o the "rapidgate fix" applied.

Otherwise, use slower/lower powered DC chargers? https://www.chargepoint.com/products/commercial/cpe100/ (yes, there is a CHAdeMO version) are only "24 kW" at max. Actually, their 55 amp at max so their max wattage is lower than 24 kW at typical pack voltages.
 
In my province the goverment has installed at least two that i know of 25 KW single phase Chademo/CCS stations. These are both in remote mountain areas where there is single phase power. Nice rest stops. Bathrooms etc. We use them but only for about 15 minutes. Pee break. Walk the chihuahua, munchies from the cooler. I’ve never paid attention to how many kilowatts we pick up in that time. Handy though. They are both on the way up huge hills. Like 30 - 40 km of hill.
 
It's probably for the best that Nissan doesn't allow this. It would be very very annoying to be waiting for a Chademo charger to open up and the vehicle getting charged was doing some sort of slow charge.
 
Most people are looking forward to faster DC charging, not slower...

https://www.theguardian.com/environment/2019/oct/30/electric-cars-could-be-charged-in-10-minutes-in-future-finds-research
 
Dave- Dr. Holland writes this in the article
"A useful partial solution would be to allow customers to manually set a peak charging rate (below the safe limit) that minimises heat gain and gets predictable results. The rate options should be 20 to 35 kW in 2.5 kW increments. Grey out/disable higher powered options as they become unavailable due to overheating risk. Ideally, make the power curves on these options flatter and less peaky (peaky = heaty). This will allow the customer to access more modest but more sustainable charging power and less overall heat gain during a long journey.

46 kW charging (adding 70%) takes 38–40 mins, but adds 20° Celsius of heat. 28 kW takes 53 mins, but adds half the heat. 23 kW charging takes 64 minutes, but adds just one quarter of the heat. 23 kW (or 22.5) would be ideal for a meal break, for example. These manual options would make a big difference to the user experience on a long journey."

The idea is to avoid, or at least, delay for a meaningful time, excessive battery heat when driving the Leaf on a long journey.
 
Tbobz said:
Dave- Dr. Holland writes this in the article
"A useful partial solution would be to allow customers to manually set a peak charging rate (below the safe limit) that minimises heat gain and gets predictable results. The rate options should be 20 to 35 kW in 2.5 kW increments. Grey out/disable higher powered options as they become unavailable due to overheating risk. Ideally, make the power curves on these options flatter and less peaky (peaky = heaty). This will allow the customer to access more modest but more sustainable charging power and less overall heat gain during a long journey.

46 kW charging (adding 70%) takes 38–40 mins, but adds 20° Celsius of heat. 28 kW takes 53 mins, but adds half the heat. 23 kW charging takes 64 minutes, but adds just one quarter of the heat. 23 kW (or 22.5) would be ideal for a meal break, for example. These manual options would make a big difference to the user experience on a long journey."

The idea is to avoid, or at least, delay for a meaningful time, excessive battery heat when driving the Leaf on a long journey.

a statement w/o regards to the size of the battery is simply folly.

to wit; On December 31st; I did a free NCTC charge session on EVGO. Lasted "around" 30 mins which charge rate at 120-121 amps for the duration. I received 22.9 kwh.

Battery temps started at 51.0/51.6/52.0
Battery temps ended at 71.4/72.0/73.4

The largest increase was 21.4º F or 13.4ºC

But that isn't even the issue. We are talking about a woefully overwhelmed network. Increasing charging time on a such a vital resource is a good idea how? What gives you the right to make this decision on your own? In a per minute billing scheme; its one thing to decide to pay the extra money for the increased time to charge but in the new Pay per kwh scheme California is so enamoured over, you simply don't have the right! In my case; a 23 kw charging rate would be well over 2 hours!

Now, if there was an abundance of money to add charging stations that cater to every need, then fine. Let me know when that happens.
 
Otherwise, use slower/lower powered DC chargers? https://www.chargepoint.com/products/commercial/cpe100/ (yes, there is a CHAdeMO version) are only "24 kW" at max. Actually, their 55 amp at max so their max wattage is lower than 24 kW at typical pack voltages.


Thanks for this. Very interesting.
 
To Whom it may concern; A Seattlite (former LEAFer, current Bolter soon to be Y'er) suggested to EA that they install "top off" chargers at 25 KW. He was advised yesterday that EA is actually considering the idea. Who knew??
 
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