2012 Gen 1. Range stated as 229km SOH at Zero percent and 10 bars goes up to 12

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martincanuk

Member
Joined
Aug 5, 2017
Messages
13
Hi all, I'm a newbie to any forum posting although I've had my 2012 LEAF for 7 years now. The Japanese made car was originally first sold/leased in Northern Washington, USA. I live in Sidney, BC, Canada which is a 'cool Mediterranean climate'. I've scanned forums for any reports of the strange behaviour that my car is displaying but didn't find anything similar. LEAFSPY indicates that I have one bad cell or battery indicated as short blue bar and the battery levels, tall red bars, look to be unbalanced. I tried the almost full discharge followed by a full charge plus wait three or more hours after the third charging lamp extinguishes. I have bought a used battery module which is in good health to replace the bad cell or battery module which is shown as being in position 79, wherever that is. I suppose I will check each module until I find the bad one. When I fully charge the battery it shows 10 bars but after driving for about 15km it goes up to 12 bars before it starts going down. I charged recently and the range shown afterwards was 229km which rose a few km while driving before falling. Turtle mode cuts in after a rapid range loss at about 25km but it varies. Could a computer problem or a battery management problem be part of the strange display behaviour? The car has almost 60,000km on the odometer of which I have done about 40000km since purchase. I have images of the LEAFSPY results and the instrument displays but I don't think that I'm allowed to post them here. I'd like to get some input from a person familiar with these strange manifestations before I open Pandora's battery box. Any light shed on this conundrum will be gratefully appreciated.
 
Welcome to the forum.

First thang to rule out is a weak or worn out 12V auxiliary battery, which can cause a multitude of faults.

If the aux is good, then what is the Min/Max/Avg cell voltage reading shown on laefspy?

You are allowed to post images, but you must put them on a hosting site such as imgur first, then use the link from imgur and it will show up here. This site can't host the images--too much bandwidth cost to do that on a free site.
 
Thanks for the quick responses, what with grandkids and working out how to post images on imagur it's taken me a while to learn stuff. The 12 aux. battery is new. I bought it from the Nissan main dealer. The leafspy readouts and a photo of the car dashboard should show more than I understand... I just have to find out how to post them here from imagur. Hopefully it won't take me too long.
 
martincanuk said:
I have images of the LEAFSPY results and the instrument displays but I don't think that I'm allowed to post them here.
Upload them to a hosting site and put the link to the image in a IMG tag in a post.

imgur.com is a popular one and it's easy to get your images inline in a post: upload the image, mouse over the uploaded image and click to the "..." in the upper right, select "Get share links" and copy the BBCode line (with IMG tags included). Paste that link into your post.

Definitely include the screenshots of LeafSpy output, as it will help to make the state of your battery clear.
 
Here are links to my images on imgur. I haven't worked out if I can display the actual images here yet. Got it now, thanks.
 
To display the image here, edit the post and highlight the links, one at a time. With the link highlighted in the editing window, select "Img" for it. That will display it here. Anyway, 126MV is high, but IIRC it's in the range that a dealership may find insufficient as evidence with their own equipment - and they don't use LeafSpy as evidence of anything. They need to see error codes that may only appear at extremely low states of charge (SOC) or even not at all.
 
LeftieBiker said:
To display the image here, edit the post and highlight the links, one at a time. With the link highlighted in the editing window, select "Img" for it. That will display it here. Anyway, 126MV is high, but IIRC it's in the range that a dealership may find insufficient as evidence with their own equipment - and they don't use LeafSpy as evidence of anything. They need to see error codes that may only appear at extremely low states of charge (SOC) or even not at all.
OP is past warranty

The 120 mv delta is at 80% SoC. It is entirely consistent with the car crapping out after 25 km. In any case, OP was wondering if he should bother swapping out the weak cell given the inaccurate and fluctuating display readings. I say yes, and if the goofy readings continue it means the pack in its current state is killing a new 12v battery.
 
Thanks for the 'walktru' jlv, Here are the links, the chart shown on my phone is the most recent, the others were taken in Feb 2021 when I laid the car up until June 2021... I've made the images much smaller c. 640x480 but they still appear very large... sorry.

NHbUOkZ.jpg
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Ok, seems that replacing the #79 might make things much better. Should I disconnect my new 12v battery as SageBrush suggests the traction battery might be killing it... until I can change the problem #79 cell/module/battery? Does anyone know where I can find a diagram of the physical location of #79 so that I don't have to disconnect more than I have to?
 
You REALLY DON'T want to mess with working on the traction battery - leave that to someone experienced with them. As for the 12 volt battery, I think you misunderstood: the Leaf just isn't good at charging the 12 volt accessory battery, and a chronically undercharged 12 volt battery can cause weird issues with the car. I don't think that that is the case here, but just in case, check the rest voltage (car off for 20+ minutes, hood left open so you can leave the doors shut) of the 12 volt battery with a multimeter. If it's at least 12.5 volts then that likely isn't an issue.
 
Hi LeftieBiker, Thanks for your concern, it's much appreciated. I am a qualified electronics/electrical tech and also have an experienced friend to help me. He has worked on the LEAF traction battery packs before and is currently converting his ScoobyDoo van with a pack and motor etc. He is also scratch-building a truck rolling chassis to accept LEAF batteries. Luckily, i also have the use of a four-poster lift. I have watched a few videos of how/where to pull the plugs and how the pack is released from the car, as well as some excellent videos on disassembly and reassembly.
 
Good! You actually have a better problem than most, as Leaf pack problems go, because it looks like replacing one module will give you good range. Usually the older packs are degraded enough that it's barely worth replacing a bad cell or two.
 
FWIW, this video shows the approximate location of your bad cell:

https://m.youtube.com/watch?v=mBBk1ABKftg

Hope you make a video to document the repair and upload it to YouTube.
 
Cell 79 is in Module MD40 along with Cell 80. MD40 is a Type A module that you would swap out to replace both Cells. A Cell consists of two of the flat polymer cells in parallel; a Module has 2 Cells in series for a total of 4 cells.

MD40 is in the right front module stack.

All of these details with diagrams plus the steps necessary to remove and replace a module are in the EVB section of the Factory Service Manual.

i don't know if the counting scheme used by laef spy is the same as used in the FSM, so more study may be needed. i don't have much confidence in an app that makes up units of measure such as Gids.
 
The only thing I would add is to try to find a module that matches the state of the other ones. All the cells should be roughly at the same state of degradation to keep the balance even.

Edit to add ^: I've read of other folks who have swapped out modules to replace bad cells and I think the data output by LSP is identical to what is in the FSM. LeafSpy just echoes what is on the CAN bus and while I don't know the details, I'd guess each cell reports its voltage along with its cell number so the numbering is setup by the cars firmware, not LeafSpy.
 
Thanks for the info guys or maybe there are gals posting as well, my apologies if there is... the video is interesting but it looks like it was an expensive project. I hope not to 'fry' anything, especially myself. I'll try to document the job but I don't want to dismantle more than is necessary. 'MD40 is in the right front module stack' is a good start made better if I get to glance at the relevant parts of the Factory Service Manual...Is there anywhere that a part of the FSM can be downloaded? In particular the EVBattery section. I believe a module has four cells which is two batteries, two cells in series and two in parallel. Please correct me if I'm wrong. The module I bought is exactly 4-0-4v but I don't know its SOH and I'm hoping I'm not SOOL... I have watched two video's of cutting open a module with a can opener and then separating cells... I certainly won't be getting in that deep! A friend bought a G2 battery pack but it was hard work separating the lid from the box... fortunately the G1 battery lid isn't glued to the box, I hope. In my post heading I say 10 bars goes to 12, It starts at 10bars from fully charged and climbs up to 12 bars and stays for quite a few km before going back down to 10. Strange eh? That makes me think that the computer needs to be reset whatever. That was the reason that I put a new 12v battery under the hood but it didn't clear the problem.
 
nlspace said:
i don't know if the counting scheme used by laef spy is the same as used in the FSM, so more study may be needed. i don't have much confidence in an app that makes up units of measure such as Gids.
Gid was named after user garygid (https://mynissanleaf.com/viewtopic.php?p=412073#p412073).

Prior to Leaf Spy, people built the original SOC meter (https://saxton.org/tom_saxton/2012/01/leaf-soc-meter-build.html) to have a better sense of SoC then the crap 12 fuel bars and GOM. '11 and '12 Leaf didn't have 1% increment SoC display.

Prior to Leaf Spy but after the above, Turbo3 was building https://www.mynissanleaf.com/viewtopic.php?t=8527. He had done some reverse engineering of the BMS back in 2014: https://www.mynissanleaf.com/viewtopic.php?t=17470.
 
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