Max regen - at what point do mechanical brakes engage?

Only time I use brakes is to come to a complete stop, otherwise, B does the job.

That said, I would love much more regen, but from what I have heard so far, the regen in the 2013 is the same as in the 2011/2012 in ECO mode, they just separated the functions (so you can use B mode without having to activate Prius/ECO mode).

JPWhite said:

dgpcolorado said:

To me that's a big deal and a frustration with my 2012 model LEAF, which lacks B mode. For flatlanders it is irrelevant.

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I test drove a 2013 LEAF recently and was spectacularly unimpressed with the B mode in the LEAF. It is still quite insipid. Having experienced the B mode in the Misubishi I-Miev I do have a frame of reference. Shame Nissan couldn't come closer to how Mitsubishi implemented their 'B mode'. With the Mitsubishi single pedal driving is very easy, with the LEAF, you still need the brakes more than I'd like.

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but B mode is still better than Eco in the 2011/12's right? so its progress...i prefer a much heavier regen as well as i feel that moderating regen with "one pedal" driving is an easy thing to get used to...

DaveinOlyWA said:

JPWhite said:

dgpcolorado said:

To me that's a big deal and a frustration with my 2012 model LEAF, which lacks B mode. For flatlanders it is irrelevant.

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I test drove a 2013 LEAF recently and was spectacularly unimpressed with the B mode in the LEAF. It is still quite insipid. Having experienced the B mode in the Misubishi I-Miev I do have a frame of reference. Shame Nissan couldn't come closer to how Mitsubishi implemented their 'B mode'. With the Mitsubishi single pedal driving is very easy, with the LEAF, you still need the brakes more than I'd like.

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but B mode is still better than Eco in the 2011/12's right? so its progress...i prefer a much heavier regen as well as i feel that moderating regen with "one pedal" driving is an easy thing to get used to...

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Yes progress is progress. Now the car has three drive modes, one can assume a software update could adjust the characteristics and performance of those features should Nissan decide to change them

I think it is at least partially limited by the maximum power that Nissan feels the battery can accept in regen... With a much larger pack, the Telsa can handle much more regen, for example.

lion said:

That said, I would love much more regen, but from what I have heard so far, the regen in the 2013 is the same as in the 2011/2012 in ECO mode, they just separated the functions (so you can use B mode without having to activate Prius/ECO mode).

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TomT said:

I think it is at least partially limited by the maximum power that Nissan feels the battery can accept in regen... With a much larger pack, the Telsa can handle much more regen, for example.

lion said:

That said, I would love much more regen, but from what I have heard so far, the regen in the 2013 is the same as in the 2011/2012 in ECO mode, they just separated the functions (so you can use B mode without having to activate Prius/ECO mode).

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The regen is presently not pack restricted. All of this can be regulated in real time.

TomT said:

I think it is at least partially limited by the maximum power that Nissan feels the battery can accept in regen... With a much larger pack, the Telsa can handle much more regen, for example.

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In isolation that makes sense. How come the i-Miev can have more aggressive B mode regen with a 16kWh pack?

Maybe they are less concerned about the impact on the pack (cavalier), or the pack can take it (better tech). Or both.

TomT said:

I think it is at least partially limited by the maximum power that Nissan feels the battery can accept in regen... With a much larger pack, the Telsa can handle much more regen, for example.

lion said:

That said, I would love much more regen, but from what I have heard so far, the regen in the 2013 is the same as in the 2011/2012 in ECO mode, they just separated the functions (so you can use B mode without having to activate Prius/ECO mode).

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If the battery can accept a charge via CHAdeMO, shouldn't it be able to take more than 30kWh? I'd assume that the limitation is because of the rpm/gearing as others mentioned.

A lot of this is going over my head, so forgive me. My commute is 25 miles one way, mostly flat roads, very few traffic lights and light traffic. I stop once in a while (the last 2 miles for instance have several lights), but mostly cruise 40-55mph. I may not have to stop for 15-17 miles if I hit the few traffic lights just right. But I will slow/speed up between 40-55 depending on the few cars on the road. In that case, am I better off in ECO or B mode?

Klayfish said:

A lot of this is going over my head, so forgive me. My commute is 25 miles one way, mostly flat roads, very few traffic lights and light traffic. I stop once in a while (the last 2 miles for instance have several lights), but mostly cruise 40-55mph. I may not have to stop for 15-17 miles if I hit the few traffic lights just right. But I will slow/speed up between 40-55 depending on the few cars on the road. In that case, am I better off in ECO or B mode?

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The mode likely won't make much difference for your described route; depends on how you drive not what mode you are in. And, to that point, trying to max out regen isn't nearly as efficient as just driving gently, unless you really need to slow down quickly.

The exception is that in Eco the power to the climate control system should be limited (it is on 2011/2012 models, I presume that is the same for 2013 models). That might save a bit of power under some circumstances, at the cost of reduced heating speed. But that's pretty small stuff compared to how one drives in general.

How about this:

coasting > regen > friction brakes

Klayfish said:

A lot of this is going over my head, so forgive me. My commute is 25 miles one way, mostly flat roads, very few traffic lights and light traffic. I stop once in a while (the last 2 miles for instance have several lights), but mostly cruise 40-55mph. I may not have to stop for 15-17 miles if I hit the few traffic lights just right. But I will slow/speed up between 40-55 depending on the few cars on the road. In that case, am I better off in ECO or B mode?

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i would say B mode but its really up to your comfort level. B mode allows more regen in case you have to stop faster than anticipated and your speed can still be regulated pretty effectively with one pedal driving when anticipation of traffic speeds is easier.

in the grand scheme of things, you dont want to regen or burn power. the prime objective is to keep power usage at zero as much as possible. So using power or regen is inevitable but the closer you keep it to zero the better.

here, there are plenty of hills so i take advantage by letting my speed bleed off a bit just before the downhill or building up speed slightly just before the accent.

Considering how often I see less than a full compliment of regen circles these days, I'd question that... That MAY be true on a new pack but does not appear to be on a degraded one...

EVDRIVER said:

The regen is presently not pack restricted. All of this can be regulated in real time.

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TomT said:

Considering how often I see less than a full compliment of regen circles, I'd question that... THAT may be true on a new pack but does not appear to be on a degraded one...

EVDRIVER said:

The regen is presently not pack restricted. All of this can be regulated in real time.

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regen is pack restricted FREQUENTLY and can be due to cold, hot, SOC, speed, etc...

RPMs are part of the equation but not all of it.

TomT said:

EVDRIVER said:

The regen is presently not pack restricted. All of this can be regulated in real time.

Click to expand...

Considering how often I see less than a full compliment of regen circles, I'd question that... THAT may be true on a new pack but does not appear to be on a degraded one...

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Since taking my car in for the latest updates at the beginning of July, I now often see only 4 regen bubbles and regen limited to 20-25 kW despite battery temps 75F+ until SOC gets below 70-75%. Never used to see that before unless it was in the winter when I presume battery temps were in the 60-65F range.

The car is much more reluctant to max out regen at 30 kW+ until the SOC is much lower and it's more difficult to keep the mi/kWh gauge pegged at 8.0 mi/kWh the first couple miles of my commute unless I am much more careful driving those first couple miles.

Not sure if this was a result of the LBC update or the "low speed grabby brakes" update as I had both done at the same time. I kind of regret having the latter done at this point in time...

DaveinOlyWA said:

i think Nissan was using this fact when boasting a big range and also the reason why it did not show up in Tony's Range tests

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Interesting hypothesis. That would make sense since the EPA tests dictate being at a particular speed at a particular time. I don't think they dictate when to apply the brakes. And, since Tony's range test was a constant speed, there was likely very little regen.

dgpcolorado said:

Seems strange to be making suggestions to someone who has been "here" so long but here goes:

Use regen only when slowing is needed. Coasting is usually more efficient so max regen is to be avoided unless significant slowing is required.

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Heh. Well, there are certain things that I paid little/no attention to as I didn't have the car yet. The same goes for Gen 3 HSI related stuff (http://techno-fandom.org/~hobbit/cars/HSI/" onclick="window.open(this.href);return false. Gen 2 Prius has no such indicator and has a different engine than Gen 3, besides a significantly redesigned transaxle and very different circuitry inside the inverter box. So, I pay little attention to how best to drive a Gen 3 Prius and use its HSI since I don't have one.

Yes, I agree that it's best to not change your speed much at all, in either direction. The principles are the same when driving a Prius.

DaveinOlyWA said:

But you had a Z before so guessing it would be easy for you to get used to going from N to D to B, etc...

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It was an automatic. I can only drive stick very poorly. On the flip side, my Z's transmission had 0 problems, unlike the folks who went thru several manual transmissions.

DaveinOlyWA said:

congrats on finally getting one! any details (or link) to share?

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Sorry, not many details. I posted about getting it at http://www.mynissanleaf.com/viewtopic.php?p=313898#p313898" onclick="window.open(this.href);return false;.

Work and other things have been keeping me busy.

Starting to get a better grip on this, thanks for the replies. I used the energy screen this morning to try to monitor what I was doing. I typically try to maintain constant speed anyway, even when I was driving my ICE cars. Doing that always let me beat the mpg ratings for the car, and always above what most others report...for instance I can get 35mpg out of my '90 Miata. I wasn't at complete zero on the long stretches of flat, open road, but fairly close. My dash currently says 3.8 miles/kwh average, so I'm getting the hang of it.

Klayfish said:

Starting to get a better grip on this, thanks for the replies. I used the energy screen this morning to try to monitor what I was doing. I typically try to maintain constant speed anyway, even when I was driving my ICE cars. Doing that always let me beat the mpg ratings for the car, and always above what most others report...for instance I can get 35mpg out of my '90 Miata. I wasn't at complete zero on the long stretches of flat, open road, but fairly close. My dash currently says 3.8 miles/kwh average, so I'm getting the hang of it.

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In that case you should do well with LEAF mileage.

You have two mileage meters, the one on the dash and one on the console (you can get to it with a button on the energy screen). I suggest that you reset one daily and you can leave the other for longer periods (I reset mine monthly). That way you can get an idea of how you are doing each day, as opposed to averaging in daily trips since you got your car. I would guess, from your description of your route, speeds, and driving style, that you are probably doing better than 3.8 miles/kWh now.

My experience exactly, drees. P3227 definitely has taken away some of my maximum available regen under numerous conditions... How much of this is due to how P3227 interacts with my degradation is unknown...

drees said:

TomT said:

EVDRIVER said:

The regen is presently not pack restricted. All of this can be regulated in real time.

Click to expand...

Considering how often I see less than a full compliment of regen circles these days, I'd question that... That MAY be true on a new pack but does not appear to be on a degraded one...

Click to expand...

Since taking my car in for the latest updates at the beginning of July, I now often see only 4 regen bubbles and regen limited to 20-25 kW despite battery temps 75F+ until SOC gets below 70-75%. Never used to see that before unless it was in the winter when I presume battery temps were in the 60-65F range.

The car is much more reluctant to max out regen at 30 kW+ until the SOC is much lower and it's more difficult to keep the mi/kWh gauge pegged at 8.0 mi/kWh the first couple miles of my commute unless I am much more careful driving those first couple miles.

Click to expand...

Adding to what Drees mentioned. since the update, my LEAF "seems" to be somewhat different.

**GOM is much more pessimistic (still overestimates but not so much)

** lost about 22 GID (265ish to 243)

** regen bubbles "occasionally" slow in appearing. Yesterday, was done two full bars and only had access to 3 circles. TB's at 6 so no extremes here to mention...

** A/C seems to not settle in the "quarter KW" range as much. Now this is a huge variance due to heat, A/C setting etc. but before it would start high about 1.5-2.5 Kw for about 2 mins then drop fast to under a half Kw more often than not a bare sliver. this is not happening. now, this Summer has been one of the hottest in recent memory (we were actually a bit below average during the Scorcher of 2012) so that might be playing a part but things like moving the temp setting from 68º (my norm) to as high as 75 has not helped...

This I haven't seen on mine... It appears to be behaving as it always has in the hot weather here...

DaveinOlyWA said:

A/C seems to not settle in the "quarter KW" range as much. Now this is a huge variance due to heat, A/C setting etc. but before it would start high about 1.5-2.5 Kw for about 2 mins then drop fast to under a half Kw more often than not a bare sliver. this is not happening. now, this Summer has been one of the hottest in recent memory (we were actually a bit below average during the Scorcher of 2012) so that might be playing a part but things like moving the temp setting from 68º (my norm) to as high as 75 has not helped...

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TomT said:

My experience exactly, drees. P3227 definitely has taken away some of my maximum available regen under numerous conditions... How much of this is due to how P3227 interacts with my degradation is unknown...

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OK, good to know at least that at least it appears to be due to the P3227 update and not due to the grabby brake update (NTB12-086).

Also seeing the same A/C power draw as usual on my car.

Not seeing max-regen very frequently is highly annoying, though.