## OK To Short Charge (30 min) To Assure Range

DaveinOlyWA
Posts: 13199
Joined: Sat Apr 24, 2010 7:43 pm
Delivery Date: 16 Feb 2018
Leaf Number: 314199
Location: Olympia, WA
Contact: Website

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

alozzy wrote: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

the cycling chart is not valid unless a "heat" factor is applied. The issue we have (that most here seem to ignore) is that there is a degradation curve that varies with temperature and that curve starts at a shockingly low temperature.

The other question is what 40% DoD means? Is that 40-80% SOC? Because if it is, that only means that issues with heat are magnified.

Finally I love Battery U for the legwork they have done but they have only recently started concentrating on the specific issues EVs face. So a realistic picture requires stitching several studies together with leaps of logic to make sense of them.

This last part is something that most refuse to accept.
2011 SL; 44,598 miles. 2013 S; 44,840 miles.2016 S30 deceased. 29,413 miles. 2018 S40; 11,987 miles, 485 GIDs, 37.6 kwh 110.89 Ahr , SOH 96.00, Hx 115.22
My Blog; http://daveinolywa.blogspot.com" onclick="window.open(this.href);return false;

alozzy
Posts: 1106
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

The takeaway is the relative comparison between different depths of discharge (DoD) for charge cycling, and how that impacts battery degredation.

Limiting the DoD to less than 50% makes intuitive sense to me, assuming it does in turn slow down battery degredation. I choose to believe that it does, based on several sources of "evidence". Of course, that doesn't mean I obsess about it and never discharge more than 50%, but I do try to "top up" when the opportunity arises.
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

LeftieBiker
Posts: 9368
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

Limiting the DoD to less than 50% makes intuitive sense to me, assuming it does in turn slow down battery degredation. I choose to believe that it does, based on several sources of "evidence". Of course, that doesn't mean I obsess about it and never discharge more than 50%, but I do try to "top up" when the opportunity arises.posting.php?mode=reply&f=9&t=25002

It seems to me, based on experiences by many, many people with lithium batteries, that 20% is the best "floor" for DOD, with 50% being more like a compromise storage charge, and 30% or so being optimum. "Top up" implies charging to full, and that definitely isn't the way to maximize lithium pack longevity, as lithium batteries don't seem to "like" being at 100%.
Scarlet Ember 2018 Leaf SL W/ Pro Pilot
2009 Vectrix VX-1 W/18 Leaf modules, & 3 EZIP E-bicycles.
PLEASE don't PM me with Leaf questions. Just post in the topic that seems most appropriate.