mpm3710
Posts: 49
Joined: Fri Jun 24, 2011 6:48 pm
Delivery Date: 26 Jun 2011
Leaf Number: 4775
Location: Maple Valley, WA

Frequent charging when battery SOC is already high.

Mon Jul 23, 2012 7:46 pm

I had my 1 yr. battery check up today at my Nissan dealer. I scored 5 stars in the categories they checked for, except one category "Frequent charging when battery SOC is already high" I only recieved 4 stars. So my question is is it better to keep topping off the battery than to wait and charge it when close to depletion to prolong the battery life?
Blue Ocean SL-Etec QC
Reserved 4/20/10
Ordered 10/28/10
Delivered 6/26/11
EV Project Blink L2 installed 6/16/11

grommet
Posts: 349
Joined: Wed Aug 11, 2010 9:57 am
Delivery Date: 03 Jun 2011
Leaf Number: 3612
Location: Silicon Valley

Re: Frequent charging when battery SOC is already high.

Mon Jul 23, 2012 7:52 pm

That just means you somewhat regularly plugged in ("topped off") your car when it was still above 80%. Nissan would like you to minimize this behavior, as it's not considered a best practice for battery longevity.

Stoaty
Posts: 4490
Joined: Fri Jun 18, 2010 9:50 pm
Delivery Date: 12 Jun 2011
Leaf Number: 3871
Location: West Los Angeles

Re: Frequent charging when battery SOC is already high.

Mon Jul 23, 2012 8:27 pm

mpm3710 wrote:So my question is is it better to keep topping off the battery than to wait and charge it when close to depletion to prolong the battery life?
Answer: Neither. To prolong the life of the battery it is best to keep it in the 20-80% range (2 bars - 10 bars). The higher the state of charge and the longer it is at that higher state of charge, the worse it is for the battery. That is especially true if battery temperature is elevated (middle of 6 bar temperature range to 7 bar temperature). If you don't need to do it for adequate range, NEVER charge to 100%. If you need to charge to 100%, it is best to have the charging finish shortly before you plan to drive the Leaf (e.g., charge to 100% by 7:00 AM if you plan to leave at 7:30 AM).
2011 Leaf with 62,000 miles given to Nephew
2013 Tesla Model S85 with 251 miles rated range at full charge
Leaf Spy Manual
Battery Aging Model Spreadsheet

DaveinOlyWA
Posts: 15145
Joined: Sat Apr 24, 2010 7:43 pm
Delivery Date: 16 Nov 2019
Leaf Number: 319862
Location: Olympia, WA
Contact: Website

Re: Frequent charging when battery SOC is already high.

Mon Jul 23, 2012 8:27 pm

neither. you should not start a charge if you are already over 80% (i only scored 4 stars on this as well...) and you should not purposefully run your battery low either.

just drive it. the other thing you should look at is why you start charging when SOC is already high. do you drive very few miles a day? if so, you should only charge to 80% and do it every other day
2011 SL; 44,598 mi, 87% SOH. 2013 S; 44,840 mi, 91% SOH. 2016 S30; 29,413 mi, 99% SOH. 2018 S; 25,185 mi, SOH 92.23%. 2019 S Plus; 14,342.8 mi, 93.16% SOH
My Blog; http://daveinolywa.blogspot.com" onclick="window.open(this.href);return false;

TimLee
Posts: 2811
Joined: Thu Jan 20, 2011 9:40 am
Delivery Date: 17 May 2011
Leaf Number: 2026
Location: Chattanooga, TN

Re: Frequent charging when battery SOC is already high.

Mon Jul 23, 2012 10:29 pm

That's the only category I only had 4 stars in too.
In one year of operation, I think I charged when the battery was >80% (10 of 12 bars), on about 3 or 4 occasions.
And it was only when I needed to for reaching my destination and it was right before I headed out and very quickly brought the battery charge back substantially below 80%.
I think their evaluation protocol on this category is a bit picky.
Kind of like it is OK to charge to 100%, but decide that when you first set up the charge.
If you find out later that you need 100% when you previously thought 80% was going to meet your needs, you get dinged for the latter. I really don't technically see how one versus the other has any different impact on the battery life.
Total # of times that charging to >80% has been selected would be more relevant indicator of impact to battery. And then its a matter of how long you leave the batter at >80%.
Key to extending battery life is avoiding leaving battery <20% or >80% for any significant length of time, especially in hot weather.

Tim Lee
Chattanooga, TN

Man. Date: 03/10/11, VIN # 2026
Delivered 05-17-2011
Blue Ocean, 2011 SL-eTec

Volusiano
Posts: 1461
Joined: Thu Feb 24, 2011 2:41 pm
Delivery Date: 03 Jun 2011
Location: Phoenix, AZ

Re: Frequent charging when battery SOC is already high.

Tue Jul 24, 2012 10:07 am

TimLee wrote:That's the only category I only had 4 stars in too.
In one year of operation, I think I charged when the battery was >80% (10 of 12 bars), on about 3 or 4 occasions.
And it was only when I needed to for reaching my destination and it was right before I headed out and very quickly brought the battery charge back substantially below 80%.
I think their evaluation protocol on this category is a bit picky.
Kind of like it is OK to charge to 100%, but decide that when you first set up the charge.
If you find out later that you need 100% when you previously thought 80% was going to meet your needs, you get dinged for the latter. I really don't technically see how one versus the other has any different impact on the battery life.
Total # of times that charging to >80% has been selected would be more relevant indicator of impact to battery. And then its a matter of how long you leave the batter at >80%.
Key to extending battery life is avoiding leaving battery <20% or >80% for any significant length of time, especially in hot weather.
I totally agree with your points here. Unless you know at the time you start recharging that you're going to need 100%, you'd only want to charge to 80%. But if your plans change and you end up needing 100% later, you should be able to charge to 100% from 80% without penalty. The logic for the penalty is flawed, because it's actually better to keep the battery on standby at 80% then charged to 100% just before you leave, than to keep the battery on standby at 100% the whole time.

User avatar
LEAFer
Posts: 2647
Joined: Mon May 24, 2010 10:10 am
Delivery Date: 19 Jan 2011
Leaf Number: 000215
Location: Sacramento Area

Re: Frequent charging when battery SOC is already high.

Tue Jul 24, 2012 10:21 am

SO ... am I interpreting this correctly ? It means you are also being dinged when you try to do the right thing: charge on End-Only-Timer to 80%, and 90 minutes before you leave hit the timer override to get to 100%.
2011 Silver SL+QC [Mfg: 11/2010] 36mo/15k LEASE
06Jun2013 Status [28.5 months][34,173 miles][11 bars]
Lost CapacityBar 6/6/13 @34,173 miles while in LEAF Battery Monitor: 83.41%, 71.4F (avg); cool overnight;

EdmondLeaf
Posts: 1500
Joined: Tue Jan 18, 2011 2:18 pm
Location: Edmond, OK

Re: Frequent charging when battery SOC is already high.

Tue Jul 24, 2012 10:24 am

Exactly, this seems like charging directly to 100% is good, but charging to 100% after stopping at 80% is bad. This make no sense, what about if I need to charge to 100% and there is power failure. Do I need to drive car around in order to go below 80% and than charge to 100%? What about people that charge to 80 all the time and need more range?

DaveinOlyWA
Posts: 15145
Joined: Sat Apr 24, 2010 7:43 pm
Delivery Date: 16 Nov 2019
Leaf Number: 319862
Location: Olympia, WA
Contact: Website

Re: Frequent charging when battery SOC is already high.

Tue Jul 24, 2012 10:33 am

LEAFer wrote:SO ... am I interpreting this correctly ? It means you are also being dinged when you try to do the right thing: charge on End-Only-Timer to 80%, and 90 minutes before you leave hit the timer override to get to 100%.
dinged is not a word i would use. like any "rule" there are usually circumstances that applies to the rule that do not apply to you and this is one of them.

once again, i also got 4 stars on this and i can tell you why. in winter, i made it a habit of starting my climate control to heat up the car so i plugged in to heat on someone else's range so to speak. it did not hurt me and i feel confident in saying that what you are doing does not hurt you.

after all its just a "guideline" kinda like the speed limit. so just treat it as that
2011 SL; 44,598 mi, 87% SOH. 2013 S; 44,840 mi, 91% SOH. 2016 S30; 29,413 mi, 99% SOH. 2018 S; 25,185 mi, SOH 92.23%. 2019 S Plus; 14,342.8 mi, 93.16% SOH
My Blog; http://daveinolywa.blogspot.com" onclick="window.open(this.href);return false;

grommet
Posts: 349
Joined: Wed Aug 11, 2010 9:57 am
Delivery Date: 03 Jun 2011
Leaf Number: 3612
Location: Silicon Valley

Re: Frequent charging when battery SOC is already high.

Tue Jul 24, 2012 10:45 am

I don't believe charging to 100% when you are sitting at LEAF 80% is reported as less than optimal behavior. I've done this dozens of times (when I need the range, via timer override)... and I still received 5 stars for that category.

The other behaviors Nissan cares about:
Time car is sitting idle over 80% after charging. (Try to use the energy over 80% within a day.)
Time car is sitting idle over 80% after driving. (If you log a lot of time here, you really shouldn't be charging to 100%.)

--Ron

Return to “Batteries & Charging”