Had the P3227 reprogram done today: interesting results.

[DaveinOlyWA]

I keep wondering if they robbed us on range with this update. I think they did, but likely overall it is not a lot of loss.

most feel the update simply gave us more accurate info. I can agree with that to a point as I had noticed loss of range without a drop in GIDs. This Spring I was still in the low to mid 270's which should have meant a range loss small enough to be hard to notice. But as Summer approached, I quickly dropped into the mid to upper 240's. I did the update and now I am just a bit lower than that

 

[Valdemar]

^^^ I meant because of less regen available. Also they never mentioned that regen algorithm was changed.

 

[DaveinOlyWA]

^^^ I meant because of less regen available. Also they never mentioned that regen algorithm was changed.

ya, at first I wondered if they felt higher regen was contributing to faster degradation but that does not explain why I see less regen when I have 5 TBs, have been driving 20 miles in late Fall, etc.

 

[EVerlasting]

I noticed this too after the update. Regen doesn't go more than three out of five bubbles until range on GOM is less than 40 miles. This doesn't make sense. Why did Nissan do this? What was the benefit of reducing regen? Maybe they did this by mistake. Maybe they don't even know about it.

 

[TomT]

After the update settled in for about a month and the BMS recalibrated itself, I noticed no appreciable range difference from that which I had prior to the update. Immediately after the update, I actually had a temporary increase in range and Gids (see my messages at the beginning of this thread for more particulars on this)...

I keep wondering if they robbed us on range with this update. I think they did, but likely overall it is not a lot of loss.

 

[TomT]

They are now aware of it and are looking in to it...

I noticed this too after the update. Regen doesn't go more than three out of five bubbles until range on GOM is less than 40 miles. This doesn't make sense. Why did Nissan do this? What was the benefit of reducing regen? Maybe they did this by mistake. Maybe they don't even know about it.

 

[abasile]

I'm wondering if this issue affects "instantaneous" regen more than "continuous" regen.

In any event, there's always been a speed-related regen "feature" (I call it a bug) that I'd love to see eliminated. While descending a mountain, I might be able to get, say, 8 kW of regen at 30 mph. Speed up to 55 mph, and regen drops markedly or disappears completely. Slow down again, and I get some regen back. As a result, I'm forced to descend more slowly than I should have to (unless I want to overheat my brakes).

I see the difference most in the 80% to 40% SOC range... Everything else being equal, there is less regen available now than before P3227... Temperature also seems to play a bigger part now as well.

Our regen hasn't been that great driving down the mountain we live on, but at a given SOC I'm not sure that it's any worse than last year.

 

[EVerlasting]

I'm wondering if this issue affects "instantaneous" regen more than "continuous" regen.

From what I see, both types of regen have been affected by the update.

In any event, there's always been a speed-related regen "feature" (I call it a bug) that I'd love to see eliminated. While descending a mountain, I might be able to get, say, 8 kW of regen at 30 mph. Speed up to 55 mph, and regen drops markedly or disappears completely. Slow down again, and I get some regen back. As a result, I'm forced to descend more slowly than I should have to (unless I want to overheat my brakes).

I think you make a good point but I don't think speed related regen should be eliminated. There is a missing ingredient in the LEAF that could eliminate this problem and increase range.

The LEAF coasts phenomenally in "N" Neutral. When I'm going downhill and if I'm not fast enough I switch to "N" Neutral. LEAF takes off and speeds up very quickly. When I notice that I am coming close to speed limit OR if I see cars getting close ahead of me, I switch to "D" Drive to slowdown with regen, and if I require to slow down more I switch to "Eco" and then finally brakes if required. I avoid using the brakes as much as possible. I have to be very attentive about what is going on far ahead of me and plan which mode I need to switch to before hand. It takes practise to get better at this. In any case, switching to any mode from Neutral is quick. This has helped me increase my range quite a bit. I live in a hilly area so I have to make best of going downhill.

Before I used to just use the "D" mode or "Eco" mode to go downhill and then regen when I was too fast, but I found this to be a little inefficient because I was still using some power even going downhill due to the LEAF not being able to speed up by itself with regen.

I think Nissan could have programed the LEAF in such a way that when going downhill if the grade is steep enough LEAF would automatically disengage the motor to allow the LEAF coast freely up to the speed desired by the driver through the accelerator and then intermittently engage regen when a particular speed has reached by driver input through accelerator. When the grade is not steep enough and the driver is still holding the same position on the accelerator pedal, LEAF would automatically engage the motor to maintain speed with power. When the driver wants to slow down, he/she reduces the accelerator pedal position or lets go the accelerator and again the motor gets engaged automatically to regen to slow down.

Instead what happens is that the motor is always engaged allowing either to use the power or regen but does not allow to coast freely unless done manually with Neutral as I do. (Others do this too according to another thread.)

So I think Nissan could improve this feature. Regen is not the only way to increase range especially going downhill, I think. Allowing the vehicle to intelligently coast when it can and then regen when the driver lets go the accelerator pedal would use less power and increase range. I have been doing exactly this but manually which takes a lot of attention and switching of the mode selector constantly.

BTW: I do this when I am approaching red traffic lights from far away. When I see a red light far away and cars beginning to slow down and stop. Even in the "D' drive mode, if I let go the accelerator, my LEAF begin to slow down a little faster than other cars. In order to stay with the traffic we have to continue using a little accelerator. Instead, I switch to Neutral for a short moment to allow my LEAF to maintain speed (sometimes with other vehicles). If I feel I am going too fast, I switch to "D" or "Eco" to slow down with regen. But if I feel I slowed down too early, I switch back to Neutral again until I feel I can comfortably slow down using regen and use the brake only to stop. I know that if I was just driving regularly, I would use some power all the way to the point when I can regen to the stopping point. Instead I don't use any power AT ALL from the point I see the red light ahead of me. If Neutral was integrated in between drive and regen, I wouldn't have to do all this. The vehicle could maintain speed without power by just coasting and then regen as I let go the pedal further to slow down.

 

[planet4ever]

Instead what happens is that the motor is always engaged allowing either to use the power or regen but does not allow to roll freely unless done manually with Neutral as I do.

Just as a point of fact, putting the car in Neutral does not disengage the motor. The LEAF has no clutch and no gears that are ever disengaged. Putting the car in Neutral only tells the inverter not to either apply energy to the motor or attempt to extract energy (regen) from it. And while we are on the subject, putting the car in Reverse doesn't shift any gears, either. The motor just spins backward.

It takes a whole different mindset. We are used to 4-cycle engines that can't run backward, so we need a reverse gear. They can't be stopped and restarted without using a starter, so we need an out-of-gear condition for when the car is not moving. All that logic no longer applies.

Ray

 

[abasile]

I'm wondering if this issue affects "instantaneous" regen more than "continuous" regen.

From what I see, both types of regen have been affected by the update.

Try it on a 2000+ foot mountain descent and get back to me.

 

[dgpcolorado]

Try it on a 2000+ foot mountain descent and get back to me.

Hah! You beat me to it. I have to use brakes to make my hairpin turns on the mountain descent. Although I do shift to neutral at the bottom of the hill for the rollout because there is another small rise to get over. The LEAF accelerates very quickly in neutral on a steep hill. When I shift to neutral in my ICE car, a '96 Jeep Cherokee with "barn door" aerodynamics, the feeling is completely different and the acceleration and rollout speed is much slower.

I have been noticing the lack of regen bubbles after the update. At a battery temp of 11ºC I am down one bubble at 30%-40% SOC. When I drive at speeds of 45 mph or more I am down two bubbles. And I also see what you first noticed long ago: higher regen at lower speeds.

So far as the bubbles and software update go, I wonder if the scale is not fixed but speed dependent? That is, four bubbles means more kW at higher speed than lower. But the energy meter does show the curious speed difference in regen energy and that predates the update, as you well know.

 

[TomT]

Of course, by simply feathering the accelerator pedal to the zero point you effectively accomplish the same thing as switching to N, but with a lot less machinations (a power meter of whatever kind makes this somewhat easier, of course)... I've become quite adept at this over the years and now only use neutral if it is a long hill and/or I am feeling lazy... I believe that any energy loss this way is negligible at worst. The salient point is that switching to N does nothing over than preventing power flow in to or out of the motor - the exact same thing that holding the accelerator at the zero point does.

When I see a red light far away and cars beginning to slow down and stop. Even in the "D' drive mode, if I let go the accelerator, my LEAF begin to slow down a little faster than other cars. In order to stay with the traffic we have to continue using a little accelerator. Instead, I switch to Neutral for a short moment to allow my LEAF to maintain speed (sometimes with other vehicles). If I feel I am going too fast, I switch to "D" or "Eco" to slow down with regen. But if I feel I slowed down too early, I switch back to Neutral again until I feel I can comfortably slow down using regen and use the brake only to stop.

 

[DaveinOlyWA]

Try it on a 2000+ foot mountain descent and get back to me.

Hah! You beat me to it. I have to use brakes to make my hairpin turns on the mountain descent. Although I do shift to neutral at the bottom of the hill for the rollout because there is another small rise to get over. The LEAF accelerates very quickly in neutral on a steep hill. When I shift to neutral in my ICE car, a '96 Jeep Cherokee with "barn door" aerodynamics, the feeling is completely different and the acceleration and rollout speed is much slower.

I have been noticing the lack of regen bubbles after the update. At a battery temp of 11ºC I am down one bubble at 30%-40% SOC. When I drive at speeds of 45 mph or more I am down two bubbles. And I also see what you first noticed long ago: higher regen at lower speeds.

So far as the bubbles and software update go, I wonder if the scale is not fixed but speed dependent? That is, four bubbles means more kW at higher speed than lower. But the energy meter does show the curious speed difference in regen energy and that predates the update, as you well know.

LEAF is the "neutral" champ for sure. I actually hit 80+ MPH (and would have been more but there is a curve at the bottom of the hill and I chickened out around 85... :shock: ) But could only get to about 80 in the Prius, 73 in the Yaris. Pretty sure I could probably hit near 90 in the LEAF as it was still accelerating pretty good when I shifted into Eco so much that I also had to apply some brake pedal. (this is the Puyallup Hill on 512 freeway for anyone who knows the area)

 

[TomT]

I've never seen any indication of that on my meter... A given number of regen bubbles has always produced the same amount of energy regardless of speed...

So far as the bubbles and software update go, I wonder if the scale is not fixed but speed dependent?

 

[EVerlasting]

Of course, by simply feathering the accelerator pedal to the zero point you effectively accomplish the same thing as switching to N

I have tried feathering the accelerator pedal to the zero point and compared it to going Neutral. There is a big difference. Even with the accelerator pedal feathered to zero point, the LEAF does not coast as freely as in Neutral. The best way to prove this is when you have feathered the accelerator pedal to zero point, go neutral and you will notice that the LEAF actually coasts faster.

 

[EVerlasting]

This discussion about automatic neutral idea is also going on here: http://www.mynissanleaf.com/viewtopic.php?f=34&t=14729

 

[TomT]

I have a gentle but long downhill run I frequent. I note the same terminal speed at the bottom in both cases...

Of course, by simply feathering the accelerator pedal to the zero point you effectively accomplish the same thing as switching to N

I have tried feathering the accelerator pedal to the zero point and compared it to going Neutral. There is a big difference. Even with the accelerator pedal feathered to zero point, the LEAF does not coast as freely as in Neutral. The best way to prove this is when you have feathered the accelerator pedal to zero point, go neutral and you will notice that the LEAF actually coasts faster.

 

[DaveEV]

So far as the bubbles and software update go, I wonder if the scale is not fixed but speed dependent? That is, four bubbles means more kW at higher speed than lower. But the energy meter does show the curious speed difference in regen energy and that predates the update, as you well know.

I don't see any relation between bubbles/speed and kW on the energy meter. Fewer bubbles mean less kW on the energy meter and the P3227 seems to knock off about 5 kW of regen compared to before the update.

I really wonder why they taper off regen at higher speeds, it seems counter intuitive. There's no reason to allow 20 kW of regen at 25 mph, but only allow 15 kW of regen at 55 mph. The battery care how fast the car is going.

Really makes me wish we had Tesla style regen - let off the accelerator and you get maximum regen regardless of the speed of the vehicle.

 

[cwerdna]

Really makes me wish we had Tesla style regen - let off the accelerator and you get maximum regen regardless of the speed of the vehicle.

B-mode on the '13 Leafs is partway there. I usually drive around in that and when I need to slow down, I try to let it slow via that and avoid using the brake pedal much (since I don't know when the friction brakes kick in).

 

[TickTock]

Of course, by simply feathering the accelerator pedal to the zero point you effectively accomplish the same thing as switching to N

I have tried feathering the accelerator pedal to the zero point and compared it to going Neutral. There is a big difference. Even with the accelerator pedal feathered to zero point, the LEAF does not coast as freely as in Neutral. The best way to prove this is when you have feathered the accelerator pedal to zero point, go neutral and you will notice that the LEAF actually coasts faster.

This is expected since the Leaf continues to draw 1-2kW of energy when moving *even if no traction power is applied*. Putting the car into neutral sets the traction power to zero so you end up pulling this overhead power from the battery. Whereas, if you feather the throttle to get to zero power to/from the battery, then regen is providing this overhead power and therefore you will decelerate faster. Which one is best for efficiency really depends on other factors but in general whichever one allows you to maintain the most constant speed is best (assuming the same average speed - if one of these techniques causes you to go slower then obviously that will be the best ).