Tandemrider
Posts: 18
Joined: Sat Jul 09, 2016 5:42 am
Delivery Date: 23 Sep 2011
Leaf Number: 008561
Location: Seattle, WA; Big Island, HI

Charging at top of hill?

Mon Aug 05, 2019 2:05 pm

My nearest level 3 charger is 18 miles away and at an elevation of 4500 ft from my home. What happens if I charge a new Nissan Leaf fully and then ride down the hill? Will I lose all of the energy that I would normally gain from the regenerative system going down the hill? Is there a buffer built in to my battery system that will allow my battery to take more charge than usual if it is generated from the regenerated braking system? Should I stop charging at 90-95% so that I can accept regenerative power from the ride back down hill?
Thanks

SageBrush
Posts: 4907
Joined: Sun Mar 06, 2011 2:28 am
Delivery Date: 13 Feb 2017
Location: NM

Re: Charging at top of hill?

Mon Aug 05, 2019 2:37 pm

^^
Potential energy in joules is mass*G*elevation in Kg, 9.8 and meters
Level ground driving is 200 - 250 Wh/mile. That is ~ 4 kWh +/- 10%

Approximately ... If the potential energy is greater than the 18 miles of level ground driving, the difference will be wasted if you start at 100% battery.

----
Unclear ?
Charge up to 80-90% and drive home. Check you SoC on arrival. Any SoC higher than you charged to says don't charge to 100%
2013 LEAF 'S' Model with QC & rear-view camera
Bought off-lease Jan 2017 from N. California
Two years in Colorado, now in NM
03/2018: 58 Ahr, 28k miles
11/2018: 56.16 Ahr, 30k miles
-----
2018 Tesla Model 3 LR, Delivered 6/2018

goldbrick
Posts: 642
Joined: Tue Aug 01, 2017 3:33 pm
Delivery Date: 01 Aug 2017
Leaf Number: 311806
Location: Boulder, CO

Re: Charging at top of hill?

Mon Aug 05, 2019 2:42 pm

You will have no regen when the battery is at 100% SOC. The regen will start when the SOC drops and will probably be noticeable around 90% (ish).

The Leaf is a heavy car and if you are going downhill for 4500 feet I'd stop charging at 90% so you can have some regen to help the brakes out. As mentioned, some experimentation will allow you to dial in the SOC that works best in this situation. Also, I believe regen decreases when the battery temp is colder so if you live where it gets near or below freezing that is another factor to consider.

Finally, Li batteries in general and Leaf batteries in particular degrade faster when stored at high SOC. Leaving the car at 100% SOC for long periods, especially if the battery is hot, is a sure fire way to accelerate the degradation.

SageBrush
Posts: 4907
Joined: Sun Mar 06, 2011 2:28 am
Delivery Date: 13 Feb 2017
Location: NM

Re: Charging at top of hill?

Mon Aug 05, 2019 3:08 pm

^^
Good points.
Another is that charging from 80 -> 100% is slooooow
2013 LEAF 'S' Model with QC & rear-view camera
Bought off-lease Jan 2017 from N. California
Two years in Colorado, now in NM
03/2018: 58 Ahr, 28k miles
11/2018: 56.16 Ahr, 30k miles
-----
2018 Tesla Model 3 LR, Delivered 6/2018

User avatar
Nubo
Posts: 5461
Joined: Fri May 28, 2010 11:01 am
Delivery Date: 31 Oct 2014
Location: Vallejo, CA

Re: Charging at top of hill?

Mon Aug 05, 2019 5:38 pm

What is the significance of the Level3 charger 18 miles away?
I noticed you're still working with polymers.

webeleafowners
Posts: 928
Joined: Mon Oct 05, 2015 5:37 pm
Delivery Date: 06 Oct 2015
Location: Okanagan Valley British Columbia

Re: Charging at top of hill?

Mon Aug 05, 2019 6:08 pm

For this reason it would be sooo nice to have a hil top or 80 percent switch. I’m surprised no one has figured a work around yet. Or a hack. :)
2015 Smart Electric Drive convertible.
2016 Nissan Leaf SV 30KWh
EV only Family...well except for the big diesel motorhome. :shock:

LeftieBiker
Moderator
Posts: 13498
Joined: Wed May 22, 2013 3:17 am
Delivery Date: 30 Apr 2018
Location: Upstate New York, US

Re: Charging at top of hill?

Mon Aug 05, 2019 6:39 pm

webeleafowners wrote:
Mon Aug 05, 2019 6:08 pm
For this reason it would be sooo nice to have a hil top or 80 percent switch. I’m surprised no one has figured a work around yet. Or a hack. :)
There are a couple of charging stations that will accept your manual input of the starting SOC, and then stop at the desired SOC. I, er, kind of thought you had one...
Scarlet Ember 2018 Leaf SL W/ Pro Pilot
2009 Vectrix VX-1 W/18 Leaf modules, & 3 EZIP E-bicycles.
BAFX OBDII Dongle
PLEASE don't PM me with Leaf questions. Just post in the topic that seems most appropriate.

webeleafowners
Posts: 928
Joined: Mon Oct 05, 2015 5:37 pm
Delivery Date: 06 Oct 2015
Location: Okanagan Valley British Columbia

Re: Charging at top of hill?

Mon Aug 05, 2019 7:11 pm

LeftieBiker wrote:
Mon Aug 05, 2019 6:39 pm
webeleafowners wrote:
Mon Aug 05, 2019 6:08 pm
For this reason it would be sooo nice to have a hil top or 80 percent switch. I’m surprised no one has figured a work around yet. Or a hack. :)
There are a couple of charging stations that will accept your manual input of the starting SOC, and then stop at the desired SOC. I, er, kind of thought you had one...
I do. It’s the juicebox 40. Yah. It can be setup like that and we have used it when charging Angela’s car. Takes some fiddling and practice but it’s doable.

Here’s the thing. Our second charger is a basic 12 amp 240 volt clipper creek unit. Short of the built in timer the leaf is on its own....unless I steal her garage parking spot....and yah...that ain’t happenen.
2015 Smart Electric Drive convertible.
2016 Nissan Leaf SV 30KWh
EV only Family...well except for the big diesel motorhome. :shock:

LeftieBiker
Moderator
Posts: 13498
Joined: Wed May 22, 2013 3:17 am
Delivery Date: 30 Apr 2018
Location: Upstate New York, US

Re: Charging at top of hill?

Mon Aug 05, 2019 7:21 pm

The upside to lower charging rates is that you can do some quick mental arithmetic, then unplug the car X hours later, at Y SOC. I do that with mine, and my L-1 charging.
Scarlet Ember 2018 Leaf SL W/ Pro Pilot
2009 Vectrix VX-1 W/18 Leaf modules, & 3 EZIP E-bicycles.
BAFX OBDII Dongle
PLEASE don't PM me with Leaf questions. Just post in the topic that seems most appropriate.

SageBrush
Posts: 4907
Joined: Sun Mar 06, 2011 2:28 am
Delivery Date: 13 Feb 2017
Location: NM

Re: Charging at top of hill?

Mon Aug 05, 2019 7:34 pm

webeleafowners wrote:
Mon Aug 05, 2019 6:08 pm
For this reason it would be sooo nice to have a hil top or 80 percent switch. I’m surprised no one has figured a work around yet. Or a hack. :)
.
Set the end time for about an hour after you plan to leave
2013 LEAF 'S' Model with QC & rear-view camera
Bought off-lease Jan 2017 from N. California
Two years in Colorado, now in NM
03/2018: 58 Ahr, 28k miles
11/2018: 56.16 Ahr, 30k miles
-----
2018 Tesla Model 3 LR, Delivered 6/2018

Return to “Batteries & Charging”