Regenerative Braking Failing?

[Rktennis]

Hi,
2011 Leaf with 28000mi.

I've slowly noticed in the last 5000mi that the regenerative braking doesn't seem to work as much as earlier. The same hills that I'd go down and generate 4 circles on the dash are now only going to 2.

Any thoughts? Is this normal? Does this require maintenance?

 

[DNAinaGoodWay]

First guess: It's colder now.

 

[keydiver]

Besides the much colder weather, where the Leaf decreases the amount of regen when the battery is very cold, have you had the P3227 update done to your Leaf? One of the side effects to this update seems to be a loss of regen:
http://www.mynissanleaf.com/viewtopic.php?f=27&t=13273&p=332641" onclick="window.open(this.href);return false;

 

[Rktennis]

Besides the much colder weather, where the Leaf decreases the amount of regen when the battery is very cold, have you had the P3227 update done to your Leaf? One of the side effects to this update seems to be a loss of regen:
http://www.mynissanleaf.com/viewtopic.php?f=27&t=13273&p=332641" onclick="window.open(this.href);return false;

This is probably it. Thank you. I did get the update and it coincides with this behavior. I rarely used my brakes before this, but now have to rely on it more.

I was hoping that I could avoid changing brake pads for a long time!

 

[Stanton]

I was hoping that I could avoid changing brake pads for a long time!

Me too. Unfortunately, I don't think Nissan will ever return/restore the Leaf's original regen capability, even with a new battery pack

 

[Mottyski82]

Could it need a change of the brake fluid? Would older brake fluid cause the regen to act differently than when the car was newer?

 

[LeftieBiker]

Could it need a change of the brake fluid? Would older brake fluid cause the regen to act differently than when the car was newer?

No.

 

[Mottyski82]

LeftieBiker, could you elaborate a bit more than a simple "No"? Do you have anything to back that simple statement up?

 

[DNAinaGoodWay]

LeftieBiker, could you elaborate a bit more than a simple "No"? Do you have anything to back that simple statement up?

"No" was pretty eloquent, but basically, they are two separate systems. The physical brakes, including the fluid, have no effect on the regen. Regen is like motor braking in an ICEV. Instead of the electric motor powering the wheels, the kinetic energy of the car in motion is absorbed by that same motor, now converting it into electricity back to the pack, slowing the car without engaging the physical brakes.

That wasn't very eloquent at all, I'm sure someone else can say it better, but it was somewhat more elaborative.

 

[derkraut]

+2 What Leftie & DNA said is correct. There is nothing wrong with your car, re: brakes and re-generation. At any rate, your brake pads should last at least 100,000 miles anyway. And, they're relatively cheap to replace; you could do it yourself in an hour or so.

 

[TimLee]

... There is nothing wrong with your car, re: brakes and re-generation. ...

Nissan P3227 software change is defective.
It badly degrades the original regeneration capability of the LEAF.
They either don't know how to fix it or don't appear to plan to fix it.

Now part of the reduction is temperature.
With battery temperature below 50F regeneration has always been reduced.
But I have not had P3227 done and this winter with declining battery capacity I have noticed the temperature caused regeneration reduction is a bit more than before.

 

[Moof]

There is also a strong speed dependence for the regen. At 70 mph I get zero regen below 50F, but slow down to 20 and I show 4 bubbles and can get about 18 kW. I am wondering if they figured out some other reliability problem with the regen system that they are keeping quiet and software patching around.

 

[joebrod]

I noticed the same issue about 3 weeks ago when my capacity dashes dropped from 11 to 10 (out of 12). I posted on the forum and was told the same thing about the software update which I had gotten some time before - I guess it turns on at a certain point automatically activates (I have 22k on my 2011).

It does however go to the maximum regen when it is down to 3 bars.

Perhaps this isn't a mistake and they did it deliberately so the battery will make through the warranty period.

 

[DaveEV]

Does the '13+ LEAF also have a big reduction in regen at higher speeds?

 

[RegGuheert]

+2 What Leftie & DNA said is correct. There is nothing wrong with your car, re: brakes and re-generation. At any rate, your brake pads should last at least 100,000 miles anyway. And, they're relatively cheap to replace; you could do it yourself in an hour or so.

Sure they're cheap, but the energy used to wear them out is not so cheap and we paid for an advanced system to recover that energy.

At 16F the other night, there was very little regeneration available over nearly the entire range of SOC, making loss of regen yet another big impact on range that occurs at vey low temperatures. Now I will say that 50 miles is a stretch below 20F OAT if there is a mountain involved. Last winter, pre-P3227, I figured that range didn't go below about 50 miles until temperatures got down close to 0F.

Considering I was able to travel about 100 miles last summer on a charge (post-p3227, but only a couple of months after), I now feel that the difference in range between hot and cold is about 2:1, making our LEAF much less usable in the wintertime than it used to be.

By way of comparison, our almost-13-year-old Honda Civic Hybrid can still regenerate 10kW of electricity, even in the cold weather, so it can hold its speed better on the nearby mountain than the LEAF does. (The HCH uses 120 NiMH D-cell batteries in series for the traction battery.). Efficiency only drops about 10% in winter versus summer in that car, partly due to all the waste heat readily available for the cabin.

 

[Rktennis]

As an early adopter (purchased July 2011 in CA and shipped it to GA), I have been really excited about some things and really disappointed with some things about the LEAF...equals to a net slightly disappointed about the whole experience. Mostly the range, somewhat how Nissan handled the whole battery issue.

I purchased with the hopes that in 10 years, I could pass along to my son, who would be a new driver...giving me piece of mind that he wouldn't be able to sneak around and go that far...but with 28000mi and loss of 1 of 12 bars already, I'm not sure if he'll make it to school on what's left of the battery!

It's like investing in a bond, I guess...with the depreciation, this turned out to be a financial lemon...but if I can hold on to the bond until maturity (10 years in my case), I would have gotten what I initially thought was a good purchase. Probably doesn't make sense, but that is how i rationalize it!