Had the P3227 reprogram done today: interesting results.

[TickTock]

for those who had it done and don't like the change in regen, if you had to do it over it again, would you delay having it done as long as possible?

No. I've never been happy about the reduced regen at freeway speeds and am disappointed that this appears to have been made worse. However, I generally try to avoid it anyway so I don't think it impacts my overall efficiency. I'm not too worried about my efficiency during an emergency stop. If you like to ride the tail of the car in front of you or you have a hill that is too steep to hold speed with regen alone you may see a reduction in efficiency, otherwise it should be minor and the improved accuracy of the capacity readings is a good trade IMO.

 

[ampitupco]

I'm extremely concerned about the loss of regen in colder temperatures after the update. The one cold spell we've had this fall, where my battery temperature was 45F, I had two regen bubbles at 50% SOC. What happens when my battery is 35F? 30F? No regen at all?

I guess I can only speculate for now.

 

[essaunders]

Interesting reports about regen. I'm in no hurry to get my 2012 reprogrammed - but I probably won't get by my year 2 battery check (and tire rotation) in January. So perhaps I'll have a direct cold-weather comparison. anybody got a link to a specific P3227-regen test I should perform? (got lots of time here to get baselines...)

 

[Valdemar]

What happens when my battery is 35F? 30F? No regen at all?

Worse, the heater will automatically turn on

 

[abasile]

What happens when my battery is 35F? 30F? No regen at all?

Worse, the heater will automatically turn on

In my case, while descending the mountain, I sometimes run the heater full blast to increase available, sustained regen. I can always open the windows, and it beats overheating the brakes.

 

[Valdemar]

In my case, while descending the mountain, I sometimes run the heater full blast to increase available, sustained regen. I can always open the windows, and it beats overheating the brakes.

I understand your logic, but are you sure running the heater actually helps to boost regen?

 

[DaveinOlyWA]

In my case, while descending the mountain, I sometimes run the heater full blast to increase available, sustained regen. I can always open the windows, and it beats overheating the brakes.

I understand your logic, but are you sure running the heater actually helps to boost regen?

it is not directly benefiting regen to run the heater but if its cold, why not enjoy the warmth from power that would normally be wasted? that is all he is saying here

 

[TickTock]

In my case, while descending the mountain, I sometimes run the heater full blast to increase available, sustained regen. I can always open the windows, and it beats overheating the brakes.

I understand your logic, but are you sure running the heater actually helps to boost regen?

it is not directly benefiting regen to run the heater but if its cold, why not enjoy the warmth from power that would normally be wasted? that is all he is saying here

That, and it will reduce wear on the brake pads. I am trying to see if I can go >100,000 on mine.

 

[TickTock]

It still isn't clear to me if the update indeed reduces the max regen during a long, steep, downhill run at freeway speed. Can someone testify to this? This would be a key distinction. It is clear to me and others that when decelerating at freeway speeds the amount available is definitely reduced with the update but I can forgive that if we are still able to get max regen on long downhill runs. I almost (almost) agree with a position to reduce instantaneous regen on the freeway since there is a lot of power on tap and a poor driver sitting less than 2 seconds behind the car in front of them could cycle a lot of energy back and forth adding undue wear and tear on the battery. One could argue that someone who drives like that is not particularly concerned about their efficiency so why not curtail it and save the battery. However, if I lived near large hills, I would be upset if I had to use friction brakes to keep from over-speeding.

 

[Valdemar]

...but I can forgive that if we are still able to get max regen on long downhill runs...

What is your definition of "max regen"? Is it peak regen kW, number of available regen bubbles, or total kWh you can put back into the battery on a particular descent?

 

[abasile]

I really haven't noticed a reduction in regen on long mountain descents that could be attributable to P3227. That's not to say I'm happy with the regen algorithms, however!

 

[Valdemar]

I really haven't noticed a reduction in regen on long mountain descents that could be attributable to P3227.

At what speeds? Do you have any scientific data to back that up?

 

[abasile]

I really haven't noticed a reduction in regen on long mountain descents that could be attributable to P3227.

At what speeds? Do you have any scientific data to back that up?

No carefully collected "scientific" data, just lots of casual observations. If there's no one approaching from behind me, I often descend at 30-35 mph to maximize regen. Otherwise, 40-55 mph. If I start the descent with not too high an SOC (say, 60%) and not too cold a battery (maybe 60 degrees), then picking up more than 10-12% charge by regen is still possible on the full 4900' descent. The sustainable regen level tends to drop the longer one has been descending. It might start out around 20 kW and end up around 5-8 kW (again, with a not-cold battery and SOC not high) by the time I reach the bottom.

 

[Valdemar]

Regen is dumbed down a lot starting from ~55mph and up, that's why you don't see much of a difference. My take on it is that for most owners the effect of the reduced regen at high speeds will be negligible, however those who drive on freeways above 55mph with lots of steep downhill sections may now have to use brakes more often which will cut into the energy that used to be put back into the battery, so reduced range may be more obvious for them.

I just wish the change in the way regen works by P3227 was clearly communicated to us by Mr. Brockman, instead the update was (purposely ?) pictured as simply an instrumentation precision improvement (good for owners) when in fact it included a change that at least in theory helps to slow down battery degradation at the cost of some range as an extra measure to avoid at least some 4CB warranty claims (good for Nissan).

 

[mwalsh]

I just wish the change in the way regen works by P3227 was clearly communicated to us by Mr. Brockman, instead the update was (purposely ?) pictured as simply an instrumentation precision improvement (good for owners) when in fact it included a change that at least in theory helps to slow down battery degradation at the cost of some range as an extra measure to avoid at least some 4CB warranty claims (good for Nissan).

I don't remember there being a time-frame for getting the update, just that you had to have the update to satisfy the requirement under the warranty. Because there is no way I'm decreasing the performance of my car right now...I can't afford to loose the miles.

So if I come to making a warranty claim down the road and Nissan denies it, then it's probably just as well I opted-out from the Klee lawsuit. Because I will "lawyer up" if I have to! :x

 

[Valdemar]

I don't remember there being a time-frame for getting the update, just that you had to have the update to satisfy the requirement under the warranty. Because there is no way I'm decreasing the performance of my car right now...I can't afford to loose the miles.

True, but most people will have it done anyway. If you don't do it, steer away from those WattStations as who knows if they will fix your fried OBC for free w/o the P3227 applied

 

[Stoaty]

Regen is dumbed down a lot starting from ~55mph and up, that's why you don't see much of a difference. My take on it is that for most owners the effect of the reduced regen at high speeds will be negligible, however those who drive on freeways above 55mph with lots of steep downhill sections may now have to use brakes more often which will cut into the energy that used to be put back into the battery, so reduced range may be more obvious for them.

I drive over the Sepulveda Pass on the 405 freeway in L.A. twice a day when working. I haven't noticed any difference in the regen if I set cruise control for 55 or even 65 MPH. Works just fine to keep me at a constant speed, no braking needed.

 

[Valdemar]

Regen is dumbed down a lot starting from ~55mph and up, that's why you don't see much of a difference. My take on it is that for most owners the effect of the reduced regen at high speeds will be negligible, however those who drive on freeways above 55mph with lots of steep downhill sections may now have to use brakes more often which will cut into the energy that used to be put back into the battery, so reduced range may be more obvious for them.

I drive over the Sepulveda Pass on the 405 freeway in L.A. twice a day when working. I haven't noticed any difference in the regen if I set cruise control for 55 or even 65 MPH. Works just fine to keep me at a constant speed, no braking needed.

Then the Sepulveda Pass is not steep enough Like I said most will never see the difference. Do you find you have to use the brakes more when you actually need to slow down, whereas before you could just let go off the accelerator pedal and the car would slow down faster so you didn't even have to use the brakes until may be the last moment? I certainly do.

 

[dgpcolorado]

Then the Sepulveda Pass is not steep enough Like I said most will never see the difference. Do you find you have to use the brakes more when you actually need to slow down, whereas before you could just let go off the accelerator pedal and the car would slow down faster so you didn't even have to use the brakes until may be the last moment? I certainly do.

My hills are steep* and the regen drops with temperatures. I lose one regen circle at a battery temp of 11ºC, 40% SOC, at slow speeds of 30 mph or so, and two circles at highway speeds.

Can't wait to see what it will be like at battery temperatures of 4ºC, never mind -10ºC (there wasn't much regen then even before the update). It isn't as if we had enough regen on our 2011/2012 models to begin with!

I am less than pleased with this change.


* My personal definition of a "steep" hill is one that requires 18 kW or more to maintain a constant velocity of 25 mph going uphill.

 

[Stoaty]

Then the Sepulveda Pass is not steep enough Like I said most will never see the difference. Do you find you have to use the brakes more when you actually need to slow down, whereas before you could just let go off the accelerator pedal and the car would slow down faster so you didn't even have to use the brakes until may be the last moment?

No, but that may be because I drive like a grandma (that's a good thing!), otherwise I wouldn't have a lifetime average of 5.6 miles/kwh. I like to do most of my slowing down by coasting to a stop, since regen is not that efficient. Sometimes I have to use a little regen if I don't time the lights on the surface streets quite right.