gmcjetpilot
Posts: 42
Joined: Mon Oct 30, 2017 6:45 pm
Delivery Date: 07 Oct 2017
Leaf Number: 305601
Location: Memphis TN

OK To Short Charge (30 min) To Assure Range

Thu Dec 07, 2017 10:07 pm

Is it OK to charge for a short time, say from 40% to 50% to assure range for the intended trip?

I try and only charge every other day, doing 2 full round trip commutes, which is about 68 miles total. I typically end up at the end of day 2 with about 15% and about 15 miles range remaining.

However on occasion I give it a short 30 minute charge before leaving for work on day 2, to give me a little reserve.

Is doing less full charges from 15% (less often) better than charging from 50% everyday?

* Charge once every two days from say 15% to 95% (with an optional short charge as required)
* Charge every day from about 45% to 95%,
* Charge every day from about 25% to 80%

Which is best for battery life and efficiency, Reading other threads charging to 80% saves in energy/cost.

alozzy
Posts: 889
Joined: Fri Jan 20, 2017 4:25 pm
Delivery Date: 18 Jan 2017
Location: Vancouver, BC
Contact: Website

Re: OK To Short Charge (30 min) To Assure Range

Thu Dec 07, 2017 10:38 pm

I would charge every day from about 25% to 80%, but then throwing in a charge to 100% once a week. Based on empirical evidence, lower depths of discharge (DoD) result in more charging cycles (see table 2 here):

http://batteryuniversity.com/learn/arti ... _batteries

Quick list, based on my memory, worst habits listed first:

  • Letting car sit in high ambient temperatures for long periods of time, plain and simple
  • Charging when the ambient temperature is high, particularly at already high SOCs
  • Habitually draining the battery to a low SOC (or expressed another way, allowing a high depth of discharge)
  • Habitually maintaining a high SOC for long periods of time, or habitually charging to a high SOC (overcharging, although the BMS manages that pretty well)
  • Habitually charging at a high rate of current (not convinced about this one, as LEAF taxis in the UK seem to have dealt with frequent DCQCs just fine)
  • Habitually leaving the car sitting at either a high or low SOC for long periods of time

I've probably forgotten a few :-)
Vancouver, CA owner of a 2013 Ocean Blue SV + QC, purchased 01/2017 in WA
Zencar 12/20/24/30A L1/L2 portable EVSE
1-1/4" Curt #11396 hitch
After market, DIY LED DRLs
LeafSpy Pro + Konnwei KW902 ELM327 BT OBDII dongle
Loving my first BEV :D

LeftieBiker
Posts: 8419
Joined: Wed May 22, 2013 3:17 am
Delivery Date: 31 May 2013
Location: Upstate New York, US

Re: OK To Short Charge (30 min) To Assure Range

Thu Dec 07, 2017 10:51 pm

Habitually draining the battery to a low SOC (or expressed another way, allowing a high depth of discharge)


There is no evidence that this is harmful, as long as the car is charged again immediately after use. It may be harmful if the car is left sitting at a very low (less than 10%) SOC for hours or days.
2013 "Brilliant Silver" SV with Premium and no QC, a 2009 Vectrix VX-1 W/18 Leaf modules, and 3 EZIP E-bicycles.
PLEASE don't PM me with Leaf questions. Just post in the topic that seems most appropriate.

alozzy
Posts: 889
Joined: Fri Jan 20, 2017 4:25 pm
Delivery Date: 18 Jan 2017
Location: Vancouver, BC
Contact: Website

Re: OK To Short Charge (30 min) To Assure Range

Thu Dec 07, 2017 11:04 pm

Based on the info I've read, the number of charging cycles over the life of the battery is significantly diminished with higher DoD cycling. See table 2 of that article I referenced for one example.

In the PNW, where I live, high ambient temperatures are infrequent and I think that's the primary reason why my Leaf is pushing 60K miles and still hasn't dropped a bar (it's getting close though, based on LeafSpy SOH and AHr). Guess I won't be getting a free battery, not that I'm really complaining...
Vancouver, CA owner of a 2013 Ocean Blue SV + QC, purchased 01/2017 in WA
Zencar 12/20/24/30A L1/L2 portable EVSE
1-1/4" Curt #11396 hitch
After market, DIY LED DRLs
LeafSpy Pro + Konnwei KW902 ELM327 BT OBDII dongle
Loving my first BEV :D

alozzy
Posts: 889
Joined: Fri Jan 20, 2017 4:25 pm
Delivery Date: 18 Jan 2017
Location: Vancouver, BC
Contact: Website

Re: OK To Short Charge (30 min) To Assure Range

Thu Dec 07, 2017 11:26 pm

FWIW, if you take the data from table 2 and assume that 100% DoD is equivalent to 80 miles (range of a new 24 kWh Leaf), then below are the number of miles one could travel until the battery degraded by 30% of its original capacity:

  • 100% DoD cycling - 48,000 miles (600 cycles x 80 x 100%)
  • 80% DoD cycling - 57,600 miles
  • 60% DoD cycling - 72,000 miles
  • 40% DoD cycling - 96,000 miles (3000 cycles x 80 x 40%)
  • 20% DoD cycling - 144,000 miles
  • 10% DoD cycling - 120,000 miles

Obviously, the range diminishes as the battery degrades but the numbers above are really just for relative comparison. Interesting that when comparing 40% DoD cycling to 100% cycling, the miles travelled doubles.

If you believe that source, then daily charging based on a 50% DoD cycle should result in a loss of 30% capacity after roughly 85K miles. These numbers seem too pessimistic to me, since I'm guessing my Leaf will have gone 120K miles by the time the SOH drops to 70% - I don't think I've averaged roughly 30% DoD charging cycles, it would likely be more like 50% DoD on average...

Perhaps the data was based on testing at hotter temperatures, with no TMS. Or it's just a bunch of BS ;)
Vancouver, CA owner of a 2013 Ocean Blue SV + QC, purchased 01/2017 in WA
Zencar 12/20/24/30A L1/L2 portable EVSE
1-1/4" Curt #11396 hitch
After market, DIY LED DRLs
LeafSpy Pro + Konnwei KW902 ELM327 BT OBDII dongle
Loving my first BEV :D

SageBrush
Posts: 2084
Joined: Sun Mar 06, 2011 2:28 am
Delivery Date: 13 Feb 2017
Location: Colorado

Re: OK To Short Charge (30 min) To Assure Range

Fri Dec 08, 2017 5:45 am

gmcjetpilot wrote:* Charge every day from about 25% to 80%

this
2013 Model 'S' with QC & rear-view camera
Bought off-lease Jan 2017 from N. California
Car is now enjoying an easy life in Colorado
3/2018: 58 Ahr, 28k miles

baustin
Posts: 604
Joined: Tue Feb 24, 2015 1:23 pm
Delivery Date: 09 Mar 2015
Leaf Number: 402162
Location: North Las Vegas, NV

Re: OK To Short Charge (30 min) To Assure Range

Fri Dec 08, 2017 2:01 pm

It is okay to do short charges to add range. It is better to charge every day, than to let the battery pack get down to a very low SOC, especially since you are going through the unnecessary effort to only charge to 95%. If your commute is far enough that the SOC is around 80% when you reach your destination, then just let it charge to 100%. This is better for the pack, as it keeps the cells balanced. Just don't let it sit for many hours at 100%, especially in high heat. Use the timer on the car so charging is finished within an hour of when you are ready to drive. If you get hot summers, then I would go to the effort to only charge to 80% every day, and use the timer to charge during the cooler hours at night. You still need periodic charges to 100% to balance the cells, I would suggest at least once every 10 days.
2013 Leaf SV - Cayenne Red - QC Port - LED Headlights

gmcjetpilot
Posts: 42
Joined: Mon Oct 30, 2017 6:45 pm
Delivery Date: 07 Oct 2017
Leaf Number: 305601
Location: Memphis TN

Re: OK To Short Charge (30 min) To Assure Range

Wed Dec 13, 2017 10:44 pm

Thanks for the very thoughtful answers. I know these are kind of abstract questions and topics beat to death. But I appreciate the help and clear explanations. I now have a grasp on the topic. I am not going to go crazy about how I charge it, but it makes sense to use some care to extend the life of the pack.

I don't like DoD. Seeing flashing lights, warnings and blank range (at about 8 miles). I am hoping to get 100K out of the battery. That should be doable. I bought the 2015 SV used with 21.5K miles and 12 bars. It has the lizard battery.

Temperatures in my area average High 74F, Low 54F, but it can get over +90's for June, July and Aug. So on those hot months I will avoid charging right after driving, because as one has pointed out heat is the killer of the battery.

LeftieBiker
Posts: 8419
Joined: Wed May 22, 2013 3:17 am
Delivery Date: 31 May 2013
Location: Upstate New York, US

Re: OK To Short Charge (30 min) To Assure Range

Wed Dec 13, 2017 11:41 pm

Does it cool off a lot at night on those Hot days? If so, charge in the early mornings then.
2013 "Brilliant Silver" SV with Premium and no QC, a 2009 Vectrix VX-1 W/18 Leaf modules, and 3 EZIP E-bicycles.
PLEASE don't PM me with Leaf questions. Just post in the topic that seems most appropriate.

DaveinOlyWA
Posts: 12812
Joined: Sat Apr 24, 2010 7:43 pm
Delivery Date: 10 Nov 2016
Leaf Number: 314199
Location: Olympia, WA
Contact: Website

Re: OK To Short Charge (30 min) To Assure Range

Thu Dec 14, 2017 8:13 am

gmcjetpilot wrote:Is it OK to charge for a short time, say from 40% to 50% to assure range for the intended trip?

I try and only charge every other day, doing 2 full round trip commutes, which is about 68 miles total. I typically end up at the end of day 2 with about 15% and about 15 miles range remaining.

However on occasion I give it a short 30 minute charge before leaving for work on day 2, to give me a little reserve.

Is doing less full charges from 15% (less often) better than charging from 50% everyday?

* Charge once every two days from say 15% to 95% (with an optional short charge as required)
* Charge every day from about 45% to 95%,
* Charge every day from about 25% to 80%

Which is best for battery life and efficiency, Reading other threads charging to 80% saves in energy/cost.


Determine how much charge you need daily then add 30% so the goal is parking your car for the night with 20-30% SOC. The additional range is for unplanned events, etc. No matter how structured your life is, they will happen.

Then charge to that level daily.

Your charging to full and not driving right away puts your pack into a situation of High SOC + extended time at high SOC + heat. The higher the SOC, the lower the temperature at which you need to be concerned so charging every other day means you are charging too much one day, not enough the other day.

In Winter the same principle applies but in your favor which is a good thing. So the colder it is, the longer you can have your car at higher SOC but still not a good idea if there is no reason to charge to full. Also keep in mind; there is generally a huge difference between range in Winter Summer so point #1 needs two figures; Summer number (which should be lower) along with Winter number (which should be higher to account for lower efficiency.)

FYI; your goal is too live as much in the middle of the pack as you can manage. Not an easy thing to do and Nissan gives you zero help on this especially without custom charge levels.
2011 SL; 44,598 miles. 2013 S; 44,840 miles.2016 S30 deceased. 29,413 miles. 2018 S40; 2483 miles, 490 GIDs, 38.2 Ahr available, SOH 99.30, Hx 114.37
My Blog; http://daveinolywa.blogspot.com" onclick="window.open(this.href);return false;

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