I want my 281!

[garygid]

WOW, sorry you got "exhausted" on the way home!

This morning, I found 100% (281 raw, 393.5 volts) on my "SOC-Meter" after my overnight charge "to 100%". I am using the Mod-L1 Nissan EVSE (12 amps) on two 120v sockets.

However, before I got done backing the 40 feet (out of the garage and slightly downhill) to the sidewalk, the reading dropped to 280 raw.

It seems that there is not much energy in the top few percent of the "faux-SOC" number that the car generates.

Also, one should not count on getting much usable energy after the last bar goes away (under about 16%, shortly after the LBW at about 17.5%).

 

[TonyWilliams]

I needed the whole 281 but only got 268 (95.3%)......

The wheels stopped turning at mile 102.9 after mostly freeway driving at a maximum of 55mph. Round trip elevation loss and gain of 1300 feet. The Dash showed 5 mile/kwh average.....

Very sorry I don't have more data points.

Excellent data points. Let's see, 5m/kWh * 21kWh = 105 miles... you did about 103. That, my friend, is a text book run.

You didn't mention how many miles you were short of completing the trip home. Obviously, the miles that you drove that weren't doing 55mph must have been slower to average 5.0m/kWh?

Finally, any chance you noticed how many miles in the 12th bar, and how many miles from the first Low Battery warning?

I'm starting to think that the very top of the charge offers us very little in terms of range (as Gary has suggested). You likely would have gotten the same 103 miles range, plus or minus a few miles, at 281 SOC.

 

[TonyWilliams]

Also, one should not count on getting much usable energy after the last bar goes away (under about 16%, shortly after the LBW at about 17.5%).

I have to admit, in the literally dozens and dozens of times that I've ventured down to single digit SOC numbers (many miles in Very Low Battery), I have never once been let down. It has been very predictable. My car has been to turtle 7 times, and each time was as predicted.

Also, I did check, exactly once, after several miles in Very Low Battery, whether the car still had the same power. It accelerated to 95 mph, just like has done any other time. (Note: I don't recommend this "test" of high power and low battery state... it doesn't do any favors to the battery).

Those instances were there is a problem with range below 17% are very, very rare, but admittedly, there can be a problem nonetheless. For the overwhelming majority of instances, the 17% of battery available at Low Battery warning will take you approximately the same distance as the 17% from 53% to 70%. You just don't have to worry about walking in the latter!

 

[91040]

Excellent data points. Let's see, 5m/kWh * 21kWh = 105 miles... you did about 103. That, my friend, is a text book run.

You didn't mention how many miles you were short of completing the trip home. Obviously, the miles that you drove that weren't doing 55mph must have been slower to average 5.0m/kWh?

Finally, any chance you noticed how many miles in the 12th bar, and how many miles from the first Low Battery warning?

I'm starting to think that the very top of the charge offers us very little in terms of range (as Gary has suggested). You likely would have gotten the same 103 miles range, plus or minus a few miles, at 281 SOC.

No complaints here regarding the car's performance. I knew I was pushing it beyond the limit especially since the last 5 miles included about a 1000' gain.

I ended about 2 miles from my destination and about 100 yards from a 1.5 mile downhill leg. I was only 2 miles from a dealer when I got VLB but I needed to be somewhere by a certain time. They picked me up and returned me later for the tow.

I probably did 11 miles on local roads around 35mph and used 0 power for 4 miles on the 1000' drop on the way down. Didn't note how many miles from the last bar and didn't set the trip meter until I got VLB. I will start setting the trip meter at LB warning since that is the data point you want.

In whining mode: if there hadn't been a 2 mile detour for a freeway transition closure or 8 extra freeway miles driven to avoid a freeway problem- I would have made it! Of course, having a place to plug in while at a 3 hour meeting or having the time to stop and charge on the way back would have solved the problem as well.

 

[ebill3]

This morning, I found 100% (281 raw, 393.5 volts) on my "SOC-Meter" after my overnight charge "to 100%". I am using the Mod-L1 Nissan EVSE (12 amps) on two 120v sockets.

This morning, after a 100% charge on L1, I saw 96.4%, 271 raw, and 392.5 volts.

As an aside, it looks like 100% charge yields right at 4.1 volts per cell, and 80% is just a bit over 4.0 volts per cell. I rather like those charge levels.

Bll

 

[TonyWilliams]

. Didn't note how many miles from the last bar and didn't set the trip meter until I got VLB. I will start setting the trip meter at LB warning since that is the data point you want.

On level ground (that you weren't on), you can generally count on half of the mileage in VLB that you had driven in LB.

At around the 5.0 miles/kWh you were operating, about 15 miles total to turtle. About 10 of those miles in LB, and about 5 miles in VLB. The ratio I use in the chart is 60%, so half is just easy and relatively safe to figure.

The best run that I'm aware of was Edmund's of 26 miles from LB to dead, and 16 of those miles were in LB, and 10 in VLB, exactly 10/16 ratio of 62.5%.

I've done 22 miles from LB to dead, with a very similar 62%-ish ratio of LB to VLB. In virtually every scenario that I've encountered, I can count on that half ratio:

************** 21July11**22July11
Low Battery-----8.6-----13.6--
Very Low-------5.5------8.4--
Total to Turtle--14.1----22.0--
Ratio of VLB/LB..63.9%.....61.7%

On the 22 July miles, I was trying REALLY hard to extend it as far as I could. I was knocking out 5.7miles/kW, with lots of hypermiling in Neutral on the downhills, and 38-43 mph on the uphills. I did run the AC the whole time, however.

 

[kg4bec]

On the 22 July miles, I was trying REALLY hard to extend it as far as I could. I was knocking out 5.7miles/kW, with lots of hypermiling in Neutral on the downhills, and 38-43 mph on the uphills. I did run the AC the whole time, however.

I've seen references to dropping the car into neutral for hypermiling, but I don't understand how it would do any good? Neutral would cause the car to free-wheel but you don't get to regen. Yes, I know regen slows the car, but if you feathered the throttle so the ball was in the middle would you not have the same effect? It just seems to me to be safer to leave the car in drive...

Cheers, Bert

 

[Stoaty]

I've seen references to dropping the car into neutral for hypermiling, but I don't understand how it would do any good? Neutral would cause the car to free-wheel but you don't get to regen. Yes, I know regen slows the car, but if you feathered the throttle so the ball was in the middle would you not have the same effect? It just seems to me to be safer to leave the car in drive...

Safer to leave the car in drive, plus if the downhill gets you going too fast (> 50 MPH for me), it is better to use regen to get some of the energy back. See this thread: http://www.mynissanleaf.com/viewtopic.php?f=27&t=5508" onclick="window.open(this.href);return false;

 

[TonyWilliams]

Safer to leave the car in drive, plus if the downhill gets you going too fast (> 50 MPH for me), it is better to use regen to get some of the energy back. See this thread: http://www.mynissanleaf.com/viewtopic.php?f=27&t=5508" onclick="window.open(this.href);return false;

I not sure how it's "unsafe" to not be in drive, but yes, if the car is going too fast, you need to slow it down. The best way is, of course, with regenerative braking, which means putting the car back in D or ECO.

Neutral does NOT mean that you're not in control of the car. By the way, what do you do when going down a hill with a 100% charge?

 

[TonyWilliams]

if you feathered the throttle so the ball was in the middle would you not have the same effect?

If you have safety concerns, please don't do it. Also, if you're able to "feather" the throttle successfully (I'm not, by the way), then sure, do that. I don't know how it can get much easier than pushing the gear selector over to the left for a couple seconds and letting gravity do it's job.

If the car slows down, put it in D or ECO and speed up.

If the car speeds up, put it in D or ECO and slow down.

Rolling in neutral is no different than rolling down a hill in D or ECO with 100% charge. You won't have regenerative braking. What's different is that no matter what you do, with 100% charge, you'll have no regen braking.

With neutral, below 100% charge, you have control of regen.

I'm sure there's a discussion in the forum about the efficiencies of the various techniques.

 

[lincomatic]

It was 60F this morning. Last night, charged to 100% starting @ midnight.
Didn't check SOC until 11:20 tonight... car sat all day unplugged. 277# 393.5V.
Tonight is already 60F. It was overcast today, high 74F. Cool night/day/night.
I'm sure any heat in the batts was radiated off hours ago. Forced charger on and
ran until it stopped automatically 3x in a row. SOC was 276# 394.0V.
The cool temps aren't increasing my SOC#.

 

[LEAFfan]

I've seen references to dropping the car into neutral for hypermiling, but I don't understand how it would do any good? Neutral would cause the car to free-wheel but you don't get to regen.
Cheers, Bert

Actually, thanks to someone on here, when I want 'N', instead of holding to the left for a few secs, I just put it in 'R' which will put it in 'N' really fast. I wouldn't use 'N' down a hill, but I can tell you that it will boost your m/kW h really quickly on flat streets. For instance, I hypermiled the last mile home in 'N' and it boosted my 5.8 to 6.3m/kW h. I've never had a car that would coast that far and maintain a fairly good speed. I had to put it in ECO to make the right turn on our street so as not to use the brakes. I've used the regen during the same distance, but it never boosts my m/kW h like it does in 'N'. If you time your lights right, you can really use 'N' effectively.

 

[garygid]

Modest temperatures, High Battery voltage (I recently saw 281 100.0% [at 393.5 volts, as I recall]), but still SLIGHTLY (almost insignificantly less usable energy, it appears) lower SOC number suggests:

1. SOC is not just a function of Pack Voltage (and temperature), but might actually use all the cell-pair voltages.
2. the battery cells might not be fully equalized.

I typically finish charging and:
1. my EVSE stays plugged into the LEAF for many hours ... so my LEAF might do several/many equalizing cycles, if needed.
2. my Mod-L1 (240v, 12a) Nissan EVSE can turn back ON again (to top-up after each equalizing session) without needing to be un-plugged from the LEAF.

Apparently, there are/were reports of some EVSEs which had trouble "turning ON" a second time. Is that still an issue?

It was 60F this morning. Last night, charged to 100% starting @ midnight.
Didn't check SOC until 11:20 tonight... car sat all day unplugged. 277# 393.5V.
Tonight is already 60F. It was overcast today, high 74F. Cool night/day/night.
I'm sure any heat in the batts was radiated off hours ago. Forced charger on and
ran until it stopped automatically 3x in a row. SOC was 276# 394.0V.
The cool temps aren't increasing my SOC#.

 

[lincomatic]

I typically finish charging and:
1. my EVSE stays plugged into the LEAF for many hours ... so my LEAF might do several/many equalizing cycles, if needed.
2. my Mod-L1 (240v, 12a) Nissan EVSE can turn back ON again (to top-up after each equalizing session) without needing to be un-plugged from the LEAF.

Apparently, there are/were reports of some EVSEs which had trouble "turning ON" a second time. Is that still an issue?

My EVSE definitely doesn't have the bug of not being able to turn on multiple times w/o being unplugged.
It stayed plugged in on Fri night at least 4 hrs after it was done charging. Is that long enough to finish the equalization cycles?
Does having the timer on interfere w/ equalization?

 

[91040]

Last night, charged to 100% starting @ midnight.
Didn't check SOC until 11:20 tonight... car sat all day unplugged. 277# 393.5V.
...Forced charger on and ran until it stopped automatically 3x in a row. SOC was 276# 394.0V.

Saw similar behavior yesterday. Charged to 100% overnight with the meter reading 95%/267. Restarted charging and saw the number increase to 95.4%/268. When I returned, after charging stopped, the meter was lower at 94.3/265.

Wonder whether this is due to variation in the battery or...?

 

[garygid]

So far we do not know when, under what conditions, etc. the LEAF will try to equalize. We do not yet have any EV-CAN logs showing enough time after charging is "finished". It is even POSSIBLE that the EV-CAN bus is not active during the equalization.

Hopefully, getting some more Logs will help us to discover answers to these questions.

One owner was told by the dealer that the LEAF only does equalization when told to do so by a Nissan Service person.

Personally, I suspect that is incorrect, ... but ... who knows?

 

[garygid]

Has anybody with NEW firmware (the April 2011 A/C fix, including the New-Bars with a hidden Reserve) gotten 281 (mine still has old firmware)?

 

[Herm]

The best SOC info you can ever have is coulomb counting, just keep track of the amp-hours used from a 100% charge down to turtle and assign a 0-100% scale to that.. all the information should be in the can-bus data, all you need to do is integrate the amps. Google it and see how it works.

http://www.mpoweruk.com/soc.htm" onclick="window.open(this.href);return false;

 

[Boomer23]

Has anybody with NEW firmware (the April 2011 A/C fix, including the New-Bars with a hidden Reserve) gotten 281 (mine still has old firmware)?

I've gotten 281 several times, Gary, with my new firmware.

Also interesting, I ran the car down to 13% charge the other day and only got 272 on a full charge that night. The day before (charging last Wednesday night), I had gotten the full 281.

 

[garygid]

It looks like we need more Logs to help determine what is going on during charging.

Most likely, the highest cell-pair voltage is what actually stops the charging.

The exact voltage value used might vary with battery (or other) temperature.
Of course, it varies substantially with the charge-to percentage.
It MIGHT even vary with the type of charging and the charge-from level.

Since the cell voltage is probably only read to something like 0.01 volts,
there could be some "granularity" in the stopping condition.

Even if the cell voltage is read to 1 mv (0.001 volt), there will be noise,
averaging, modeling, and estimations in getting usable values.

These "uncertanties" will tend to make each charge-session stop
at a slightly different point, even if temperature, charge-to goal, etc.
are all the same.

Usually, the actual differences in usable energy is almost insignificant.
But, keep in mind that a small (1% or 2%) difference, perhaps due to temperature
(or noise), WILL give you SIGNIFICANTLY different range, if you are trying
to use the "last mile" to get home.

It may be BETTER to learn WHEN to get a bit extra "padding" charge
rather than to see how often one has to push, or get towed home.

The wiser and more skillful use, that "appears" better to the rest of
the "unconverted" ICE drivers is NEVER needing a tow, ...
NOT the eeking out of another 1231 feet before it "died", ... again.