rajthehippiecar
Posts: 1
Joined: Wed Sep 12, 2018 11:54 am
Delivery Date: 12 Sep 2012

Regen always on

Wed Sep 12, 2018 11:58 am

Hi, I’m new here so I don’t know if I’m doing this right. I have a question about my Leaf and I can’t find any answers on google.

My dad bought a 2012 Nissan Leaf in ~2014. He drove it 40 miles a day for two years. When he sold it to me last year, the range indicator had lost two bars.

I’ve done mostly city driving, about a total of 20-ish miles a day, and I charge my car when it shows anywhere from 20-40 miles. Until two weeks ago, the regenerative braking wouldn’t kick in until there were about 65 miles left. My range indicator says anywhere from 70 to 90 miles when fully charged. I’d tell my battery capacity but I don’t remember it.

Recently, regen has stayed on. My dad doesn’t know why, and he knows a lot about EVs, so I’m totally lost. The regen is on as soon as I start driving when it’s fully charged. Now I can usually squeeze in 5 or 10 more miles than I could before since the regen is always going. I rarely use eco mode.

Is this supposed to happen when the battery degrades to a certain capacity, and has anyone here had experience with this?

Reddy
Posts: 1539
Joined: Fri Feb 11, 2011 3:09 pm
Delivery Date: 18 Aug 2011
Leaf Number: 006828
Location: Pasco, WA

Re: Regen always on

Wed Sep 12, 2018 12:42 pm

rajthehippiecar wrote:Hi, I’m new here so I don’t know if I’m doing this right. I have a question about my Leaf and I can’t find any answers on google.

My dad bought a 2012 Nissan Leaf in ~2014. He drove it 40 miles a day for two years. When he sold it to me last year, the range indicator had lost two bars.

I’ve done mostly city driving, about a total of 20-ish miles a day, and I charge my car when it shows anywhere from 20-40 miles. Until two weeks ago, the regenerative braking wouldn’t kick in until there were about 65 miles left. My range indicator says anywhere from 70 to 90 miles when fully charged. I’d tell my battery capacity but I don’t remember it.

Recently, regen has stayed on. My dad doesn’t know why, and he knows a lot about EVs, so I’m totally lost. The regen is on as soon as I start driving when it’s fully charged. Now I can usually squeeze in 5 or 10 more miles than I could before since the regen is always going. I rarely use eco mode.

Is this supposed to happen when the battery degrades to a certain capacity, and has anyone here had experience with this?
Great questions. You can more closely follow how much regen is available by looking at the circles (bubbles), regen to the left, acceleration to the right. You need two concentric circles to indicate that regen is available, the more the better. More below:

You can only regen when the battery isn't fully charged. You can't put energy in, if there's no place to put it. You would be best suited to charge to 80% (or less) everyday. Then you get regen to start immediately, Also, regen decreases with 1) battery age (yours is very old so you should expect reduced regen, maybe even zero at times), 2) temperature (you don't list your area, but it's starting to cool off in most of the US so you should expect reduced regen, especially in winter below 50 F), 3) type of battery (unfortunately, the 2012's have the old, crappy battery which has degraded more quickly than others). 4) Speed, which is very infuriating, because for some reason Nissan limits regen at highway speeds, sometimes to zero, 5) State of Charge (again, you can't add more to a battery that's already full), but this is somewhat tricky because Nissan, and all other cars, hide a small amount that the user cannot access, both on the top and bottom of the battery. How much is really unknown only to Nissan, but it is thought to be 5-10%. Thus, a 24 KWh battery might only have 21 KWh actually accessible to the user, some of which is at the top and some at the bottom. This helps reduce battery degradation because fully charging and discharging is more damaging to a lithium ion battery than only charging from 20% to 80% (which you should try to do since you only drive 20 mi/day). Unfortunately, the amount hidden at the bottom, below low and very low battery warnings (LBW, VLBW) is actually quite significant and thus you aren't really charging where you might think. Most people incorrectly charge to full, even if they don't need the range, and might discharge to only 6-7 bars. These batteries are best stored around 20-40%, which is actually only 2-4 bars. 4-5 bars is right around 50%. I typically drive 10 mi daily and charge for about an hour, trying to keep the battery around 3-5 bars. This gives me the maximum amount of regen, reduces battery degradation (for my conditions), and still meets my driving needs. Absolutely, I will charge to 100% when needed and then do my drive, usually once or twice a month, and I don't worry about it at all.

I would guess that you Dad's 40 mi RT was perfect for the Leaf. Your use is better for the older Leaf, so a perfect hand-me-down. Thank you, to both of you, for driving electric! You may have jumped on and off of the freeway, so are now seeing differences in regen. Or changing fall temperatures are the driving factor. In any case, you will see varying levels of regen throughout the year and as the battery ages. Try your best to keep the charge level around 50% and you will stress the brakes less and enjoy your driving experience more. Oh, and winter just sucks, trust me.
Reddy
2011 SL; 9 bar, 45.80 AHr; 45,000 mi; rcv'd Aug 18, 2011
Long: http://www.mynissanleaf.com/viewtopic.p ... al#p226115"
Cold: http://www.mynissanleaf.com/viewtopic.p ... 60#p243033"

damo56
Posts: 4
Joined: Wed Jan 24, 2018 2:49 am
Delivery Date: 24 Jan 2018
Leaf Number: 045445

Re: Regen always on

Mon Nov 05, 2018 6:08 am

thanks for a very interesting & informative article. I have one follow up question if I may. when I bought the leaf the salesman told me not to put regen braking on over 50mph. was he correct? if he just said that because there is no increase in battery power when going over 50mph then I might as well leave it on all the time if it does no harm? I hope this question hasn't been covered before as I did try to look through the 995 posts on the topic! kind regards damian

Levenkay
Posts: 491
Joined: Mon Sep 26, 2011 10:01 pm
Delivery Date: 11 Aug 2018
Leaf Number: 308382
Location: Portland, OR

Re: Regen always on

Mon Nov 05, 2018 11:38 am

damo56 wrote:thanks for a very interesting & informative article. I have one follow up question if I may. when I bought the leaf the salesman told me not to put regen braking on over 50mph. was he correct? if he just said that because there is no increase in battery power when going over 50mph then I might as well leave it on all the time if it does no harm? I hope this question hasn't been covered before as I did try to look through the 995 posts on the topic! kind regards damian
Are you sure he wasn't just speaking of the "e-Pedal" feature? I think that the concern has more to do with traffic safety (and maybe energy efficiency) than avoiding harm to the vehicle; my understanding is that the e-pedal is limited to 0.2g, so it's not like there'll be huge regen even at highway speed. But in 60+mph highway traffic, other drivers aren't going to expect the abrupt decelerations that the e-pedal will produce.

User avatar
Stanton
Posts: 2105
Joined: Thu Feb 03, 2011 10:56 am
Delivery Date: 01 Sep 2011
Leaf Number: 7458
Location: Plano, TX
Contact: Website Twitter

Re: Regen always on

Mon Nov 05, 2018 3:23 pm

rajthehippiecar wrote:Is this supposed to happen when the battery degrades to a certain capacity, and has anyone here had experience with this?


Definitely not: regen essentially disappears as the battery pack degrades. I was experiencing this by the time I was down 2 bars. Not only that, cold reduces regen as well. I think there's something else going on either with the controller or the brakes themselves.
2011 Blue Ocean SV w/floor mats & window tint
12v LiFePO4 battery & FIAMM 74100 horns
Wet Okole seat covers (front)
Tor's low-power heater mod
2013 sun visor
3G modem upgrade
L2 EVSE Upgrade
Battery Pack replaced (Rev E) @51 months and 41k miles

damo56
Posts: 4
Joined: Wed Jan 24, 2018 2:49 am
Delivery Date: 24 Jan 2018
Leaf Number: 045445

Re: Regen always on

Tue Nov 06, 2018 12:55 am

thanks for reply. Mine is 2017 leaf so doesn't have epedal but I can take confidence from your reply that I can leave it on more than I have been doing. I'll switch it off at 55mph+

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