Does battery need calibration?

[aibo]

2013 SL (13k miles)

Since the start of the summer, I found the battery % gauge reading is not very consistent. During the winter, it shows 80% when the charging is finished. It only shows 79%. Not sure if it's a common issue.

This morning I made a 29 mile round trip.

From Home to School:
79% -> 61% (net 18%)
CarWings 5.7 miles/kWh

If 100% is 21kWh, 18% is 3.78kWh. 14.5 miles / 3.78 = 3.8 miles/kWh

From School to Home:
61% -> 47% (net 14%)
CarWings 4.8 miles/kWh

If 100% is 21kWh, 14% is 2.94kWh. 14.5 miles / 2.94 = 4.9 miles/kWh

The return trip calculation is right on. I also found the SOC % drops much faster in the beginning (from 79% to 75%).

 

[Stoaty]

The battery gauge reads percent state of charge (SOC) which gives a rough guide to how much energy is stored in the battery when it is new, but is not the same thing. Minor variations such as you describe are normal.

 

[TomT]

Also remember that it is only showing how full the "tank" is, not the actual amount of fuel in the tank, and that the tank size and capacity can vary with changes in temperature and battery degradation. That is why many of prefer the various forms of Gid devices which can show the actual amount of energy available and the true battery capacity.

The battery gauge reads percent state of charge (SOC) which gives a rough guide to how much energy is stored in the battery when it is new, but is not the same thing. Minor variations such as you describe are normal.

 

[aibo]

CarWings shows 5.7 miles/kWh and the calculation done based on SOC is 3.8 miles/kWh. That's a pretty big difference to me. Is SOC something we can trust? To me the CarWings readings seem more accurate.

The battery gauge reads percent state of charge (SOC) which gives a rough guide to how much energy is stored in the battery when it is new, but is not the same thing. Minor variations such as you describe are normal.

 

[aibo]

I understand the SOC is not always 100% accurate. However, the car is less than 1 yr old with 13k miles. The temperature is around lower 70s (CC is off). I expect the readings would be more consistent. I made a round trip back to back. The first trip was 50% off and the second trip was right on. That's what puzzled me.

Also remember that it is only showing how full the "tank" is, not the actual amount of fuel in the tank, and that the tank size and capacity can vary with changes in temperature and battery degradation. That is why many of prefer the various forms of Gid devices which can show the actual amount of energy available and the true battery capacity.

 

[johnrhansen]

the battery stops charging the moment it hits 80 percent. Doesn't take a lot of time for the charge to bleed off when the car is just sitting there and it goes to 79 percent.

 

[LeafinThePark]

I am seeing very similar behavior. I have the charger set to charge to 80% and be done at 6:30am. I leave home at about 7:00am and the %charge is 79%. Within the first mile it will drop to about 76% and then down to 74% in the next mile. After this, the rate of drop is right about 1mi/1%. Yesterday I was running the AC to clear the windows...was warm, humid, and raining. Today was a perfect 61 deg so I had no climate control on. Behavior was the same in both cases.

This same thing happened this winter when it was very cold. I attributed it to the fact the garage would be around 20deg while it was -10 or colder outside, and I lost capacity when I started driving and the car+battery were cooled off. Now the garage is pretty much the same as outside so this does not seem to be the case.

Car is about 14 months old at is just under 15k miles. The battery check at 10k was all good.

I am going to try a 100% charge and see if the behavior is the same.

 

[TomT]

FYI: The battery check provides no useful information to us, the owner. (Nissan gets far more info but neither us nor the dealer have access to it.) It will almost always be 5 stars across the board...

The battery check at 10k was all good.

 

[DaveinOlyWA]

OP; where you live? what was temp during each trip? where you store car at night? what is temp there?

 

[cwerdna]

2013 SL (13k miles)

Since the start of the summer, I found the battery % gauge reading is not very consistent. During the winter, it shows 80% when the charging is finished. It only shows 79%. Not sure if it's a common issue.

FWIw, I've been frequently seeing similar behavior on my '13 SV (leased end of July 2013) w/a bit over 10K miles when I charge to 80%. I'm not worried about it.

See http://www.mynissanleaf.com/viewtopic.php?p=339977#p339977" onclick="window.open(this.href);return false; as to why.

 

[LeftieBiker]

Mine now reads 79% more often than 80%, at 7800 miles.

 

[aibo]

I am in Ontario, Canada. The temperature was around 65F on both trips. The car was stored in garage and the temperature was about the same. The battery temperature gauge showed 5 bars.

OP; where you live? what was temp during each trip? where you store car at night? what is temp there?

 

[aibo]

I am not worried about 79% vs 80% at all. I am more concerned why the SOC % drops so fast in the beginning of the trip (or when the battery is close to 80%).

2013 SL (13k miles)

Since the start of the summer, I found the battery % gauge reading is not very consistent. During the winter, it shows 80% when the charging is finished. It only shows 79%. Not sure if it's a common issue.

FWIw, I've been frequently seeing similar behavior on my '13 SV (leased end of July 2013) w/a bit over 10K miles when I charge to 80%. I'm not worried about it.

See http://www.mynissanleaf.com/viewtopic.php?p=339977#p339977" onclick="window.open(this.href);return false; as to why.

 

[DaveinOlyWA]

I am not worried about 79% vs 80% at all. I am more concerned why the SOC % drops so fast in the beginning of the trip (or when the battery is close to 80%).

2013 SL (13k miles)

Since the start of the summer, I found the battery % gauge reading is not very consistent. During the winter, it shows 80% when the charging is finished. It only shows 79%. Not sure if it's a common issue.

FWIw, I've been frequently seeing similar behavior on my '13 SV (leased end of July 2013) w/a bit over 10K miles when I charge to 80%. I'm not worried about it.

See http://www.mynissanleaf.com/viewtopic.php?p=339977#p339977" onclick="window.open(this.href);return false; as to why.

single trips should not be used as a gauge for anything, especially one way trips done at different times of the day. do several round trips recordings, vary the route. do at least 5, preferably 10 trips per route. use at least 3-4 routes if possible. tough challenge, but only way to get a real handle on what you can expect.

 

[johnrhansen]

I really notice the drop you speak of when I am charged to 100 percent. I always reset the energy economy indicator, and find for the first 5 miles of the trip, I only get 3 or so. The charge drops off to match. The last time I did this was when I was commuting to everett. I had preheated the car, so it was not the heat that did it. All I could figure is that 100 percent was really 97 or something,

 

[LeafinThePark]

I really thought it was interesting that on Tuesday I really saw a strange drop at the beginning of my day, and when I can in here to post there was another poster that had the same thing happen. On that day, I dropped from 79% down to 59% (20% drop) in my first 13 miles. Since then I have taken careful note of the first 10 miles or so each day and I have not noticed this at all since. On Wednesday I saw a 9% drop in my 8 mile trip to work. Thursday I charged to 100% and on the first trip I only dropped 13% during the first 13 miles. Today it was another 80% day, and I again dropped 9% in 8 miles.

So since Tuesday I have been almost right at 1%=1mi, while on Tuesday I think my SOC dropped from 79% to 74% in the first mile of my drive.

Any insight? Weather has been quite consistent all week....mornings have been between 60 and 65F with highs right around 80. Our detached garage is just slightly warmer that the outside each morning. My 2013 SV was leased in March 2013 and just hi 15k miles.

 

[LeftieBiker]

What about wind? A stiff headwind could do that.

 

[DaveinOlyWA]

I really notice the drop you speak of when I am charged to 100 percent. I always reset the energy economy indicator, and find for the first 5 miles of the trip, I only get 3 or so. The charge drops off to match. The last time I did this was when I was commuting to everett. I had preheated the car, so it was not the heat that did it. All I could figure is that 100 percent was really 97 or something,

i suggested that the LEAF has a bit of a warm up cycle as well along with shaky instrumentation and and bit of "float" charge. Float charge is a slightly higher than actual voltage reading on the battery and is accentuated when the pack has recently finished a charge which seems to be common here especially in warmer climates.

I take another view of this practice thinking I prefer the charge be completed just before the coolest part of the day so it has more of a chance to cool down before driving and adding more heat.

but like you, I start out very low in the 2-2.5 miles/kwh range for the first 2-3 miles then work up from there.