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Dala's Leaf buildthread (2015 Nissan Leaf)

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  • Dala
    started a topic Dala's Leaf buildthread (2015 Nissan Leaf)

    Dala's Leaf buildthread (2015 Nissan Leaf)

    So I thought I might start a project thread on this car, that wasn’t supposed to be a project.

    I recently picked up a commuter, 2015 ZE0 24kWh Nissan Leaf, with 5k km on it. It has extremely low range, the guess-o-meter(GOM) on the dash says 160km, but as soon as you start driving it you are lucky if you manage 20km. Pretty shite for 15 000€ (Yes these cars are extremely expensive in Finland!)

    Due to this being an USA model imported to Europe, so I apparently don’t have any battery warranties in place. I also wasn’t fully aware that the battery was this bad, so if I could go back in time I would have never bought this car.
    But nevertheless, let’s stay positive and start fixing this car up.
    Here’s a picture of the bog standard car. Not much to say really. Was a wet day.


    The car seems to deplete about 3-4kWh of battery, and then promptly report it as empty. This is strange, since it’s supposed to be a 24kWh battery! Charging it back up also goes suspiciously fast, so something is indicating that one or more cells are dragging the whole pack down.

    It also goes into turtle mode from time to time, and with a handful of dash warnings and load reductions.


    So next order of business is to start diagnosing the battery. The CAN communication needs to be forwarded to a phone running the LeafSpy Pro app. This is achieved with a bog standard v1.5 ELM327 Bluetooth OBD2 dongle. Note that it has to be v1.5, the cut down v2.1 won’t work.
    So here are some screenshots from a fully charged battery. Notice anything suspicious?


    So as you can see, the cellpair 57&58 are down 150mV from the rest of the cells. The Nissan battery management system utilizes passive balancing of the lithium cells using shunt resistors. Unfortunately, these are not very beefy, and can only bypass a few mA when charging. So if any cells have drifted far enough, and ESPECIALLY when replacing cells, you need to pre-balance them before you insert them into the pack.

    So a manual rebalance of 57&58 seems like the best way forward. Later down the line I can always replace them, but let’s start with a rebalance.

    First thing to do is disconnect the 12V battery in the front, or else the control system will freak out when I start disconnecting HW stuff


    Next thing to disconnect is the fuse from the HVDC pack. The fuse is located under the floor, and can be accessed via a panel in the backseat floor.


    After pulling the fuse, it is now safer to work under the car, and next step is to disconnect the high voltage cabling from the pack. Notice that I’m wearing Class 0 high voltage gloves each time I’m near anything labelled orange.


    Started propping up the car high with multiple failsafes.


    Removed splash plates. There are three of them.


    Here are the battery high voltage connections and CAN cabling, disconnected them. They were quite hard to figure out how to open.


    I then put pressure on battery with some wood and four jacks, started loosening bolts. There were 18mm, 8 in total.


    Built a dolly to be able to slide the pack around. The battery weighs circa 280kg!


    Lowered battery onto dolly


    Then it was very easy to slide the battery out


    For some reason they don’t want you to be able to open it easily. It was glued shut, but with the help of some prying and cutting tools, it eventually came apart


    Here is the battery exposed. Several stacks of modules, totalling at about 400V DC. Safety first, so gloves on at all times now!


    I then started to charging. Decided to take it slow due to not knowing much about the Li-MnO2 cells (I'm more of an 18650 guy ) Since the cellpair 57&58 was at the absolute bottom of the stack, they will be extremely hard to get to. I don't want to disassemble the pack, so I improvised some sticky leads with hard drive magnets inside alligator clips. That way I can just lower them down into the pack, and they will stick to the terminals.


    I then hooked up a bench supply, set it to 8.4V and connected it to the outer terminals of the 2S cell. I am lucky that the rest of the pack is at 4.00V cell average, so I won’t have to worry about CC/CV switchover, just CC charging up to 4V (8V effective due to 2S). As charge current limiter, I set it to 0.3Amps, to keep temps and everything nice and smooth.


    I also disconnected some of the BMS leads, don't know if this was necessary, and hope I don't break the BMS by piggyback charging this way.

    After 18h of charging, the cells are up from 3.60V -> 3.95V, so just a few more mV to go!

  • Kaktus
    replied
    Looks great with the debadged boot lid!

    As for the beaten up Norwegian LEAF, are you planning on getting the batteries or something from it? Or perhaps buy it outright and do it up?!?!

    Leave a comment:


  • Dala
    replied
    Something that has been bothering me is how the underside of the car looked. The front subframe had some damage that probably came from when it was shipped in a container and strapped down. Two sheetmetal holes on both sides were ripped, so I smacked the metal back into shape with a hammer, and painted over it with some paint so it wont rust prematurely.

    Second annoying thing is the ripped splashshield. This is an important piece, both for aerodynamic reasons, but it also prevents dirt and slush from being slinged up into the engine bay, and back to the battery pack.


    I fashioned a temporary fix made out of some leftover plastic, tied it togheter with zipties. I will try to source a proper replacement piece later on, preferably from a used car, since they charge $$$ for a new OEM one.


    The zero emissions rear badge also went. Looks soo much cleaner!


    Oh, and someone had a bit of a tumble in Norway last week. You know what this implies...

    Leave a comment:


  • Kaktus
    replied
    Originally posted by Dala View Post
    Maybe I should remove the 'zero emission' badge aswell?
    Yes, looks good without the LEAF badge, and I agree it would look even better if you also remove the 'zero emission' badge. it looks a little lopsided now, unfortunately... And perhaps remove the same badges from the doors as well while you're at it?

    It would give the car an overall cleaner look.
    Last edited by Kaktus; 10-07-2019, 07:51 PM.

    Leave a comment:


  • Dala
    replied
    I have been thinking about shedding some weight of the car. Preferably in places that you won't notice (unless reading it here). The fuse cover is beefy on the leaf, and weighs more than you'd think. You can see in this picture that the casting material is very thick, so I dremeled off half of it. Didn't bother with an after picture, it was quite messy...


    Speaking about removing stuff, I decided to de-badge the LEAF emblem in the rear


    Maybe I should remove the 'zero emission' badge aswell?


    Here's another interesting thing, look at how the Ahr,SOH and HX(internal resistance) has changed over just a few days


    The LBC is quickly sensing that the new battery is performing great!

    Leave a comment:


  • Dala
    replied
    I now have some data! Did a lot of driving over the past days to get a feel for the new pack. I managed a comfortable 205km at 15-13*C with no AC or heat. I averaged 7.3km/kWh, due to me slowing down after going past 0.0% SOC.

    The first 100km I drove 85-100km/h. The second 100km I drove between 70-85km/h. Here is what the 24 LBC instrumentation said:

    16% dash, 114km travelled. Low battery warning!
    8% dash, 135km travelled. - - - km remaining
    - - -% dash, 142km travelled, - - - 3.66V min cell voltage (Leafspy 12.3% SOC)
    150km travelled, 3.64V min voltage (3.61V under load), (Leafspy 7.6% SOC)
    165km travelled, 3.58V min voltage (3.53V under load), (Leafspy 0.0% SOC)
    205km travelled, 3.37V min voltage (3.30V under load) (Leafspy gave up a long time ago...)

    I could probably have kept driving until turtle, and waited for the contactors to open, but I really didn't want to strand myself. Taking it slow, it would probably been possible to drive 220-230km on a single charge. I love the 30kWh battery, but the instrumentation needs fixing asap, Half of the range is left after it indicates the first low battery voltage lol!

    Leave a comment:


  • Dala
    replied
    After completing the pilot project upgrade on my personal car, here are some random thoughts and info for the bruteforce 24-30kWh upgrade.


    Here are the two battery management systems. Nissan refers to these boxes as LBCs, (Lithium Battery Controller) The top is from the 24, bottom 30.

    Serial 24: 293A09RB3A
    Serial 30: 293A04NR5B

    They are mechanically very similar, but you cannot use the 24 LBC with a 30 Busbar. There are people on the forums who tried this, and supposedly it will short the module, since a pin or two are not the same. It would be good to document this later on, since it takes quite some time to do a busbar swap, but I am playing it safe this time.

    Oh, and the 30 box speaks kind of the same language, but pairing it with an 24 vehicle control module will result in a whole can of worms in the form of DTCs and turtle mode, since the bootup handshake afaik is different. This is being worked on by multiple people, so this will change soon.

    Speaking about busbars, here is the rear stack of modules.


    These are 30kWh modules, identified as "16B70 04###". You can also see the busbars, along with the tiny sensoring and balancing leads. These will only shunt 9mA, so it is OK for them to be such a tiny diameter. I am pairing the 30 cells with the 24 busbars.

    Funfact, the 24 pack has 2/3 temperature measurements on the outside edge of the cells, but the 30 pack has temperature measurements directly on the busbars. Measuring it directly on the busbars will for sure result in higher and more responsive temperature measurements, so I guess that is why the 24 pack also "measures" colder than 30/40 packs.

    Another thing I dediced to play safe was the contactors


    The contactors had slightly different serial numbers, but they probably would have been interchangable. Didn't feel like this was the correct time to gamble

    Getting the 30kWh cells to fit presented a few minor problems. First, the rear stack's support beams wouldn't fit onto the cells. The cutouts at the end had to be made oval instead of round to fit the stack. Nothing a saw can't fix.


    Then, the mounting holes for the rear stack did not align properly with the bottom shell


    So I had to lift out the rear stack again (heavy!) and carefully file the holes to the proper shape. After that the bolts could be installed.


    After everything was swapped over, I installed the hybrid 24/30 pack into the car, and it happily booted up with the lovely startup sound. After having the 12V battery disconnected the car always goes into miles/Fahrenheit mode, minor annoyance :P


    I will now do a shakedown of the car before diving into correcting the instrument-cluser with the CAN-bridge.
    Last edited by Dala; 05-07-2019, 06:00 PM.

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  • Dala
    replied
    So, I've run some capacity tests on a few cells, here are the results


    Antimatter Test, 5Amp discharge, from 4.1V -> 3.3V
    USA 24kWh cell: 39,77Ah
    Italy 24kWh cell: 43,30Ah
    30kWh cell: 59,0Ah

    So if I have a USA cell in my pack now, I would get a 48% capacity increase by installing the 30kWh cells. My summer vacation starts on Friday, so then I can start working on this fulltime!

    Sideproject, printed grocery bag hooks for the luggage space. Makes the car a better grocery-hauler!


    Worked really well! Found them on thingiverse: https://www.thingiverse.com/thing:361948

    Oh, and I started modeling my own creation for another sideproject on the Leaf More on that later!

    Leave a comment:


  • Kaktus
    replied
    Very good point Dala re safety when working with electrics, one can never be too careful about that sort of black magic!!

    Leave a comment:


  • Dala
    replied
    Thanks Now here's some progress,

    I took delivery of the first battery-pack from Norway! It was dusty, came from a crashed 30kWh Leaf. Shipping from Norway->Finland was only 200€!


    After getting it home and cleaning it up, the label identifies it as a 30kWh pack made in the UK.


    After splitting the case open. You can already spot the big double-stacked modules! The complete battery weighs roughly 20-30kg more than a 24kWh battery!


    Next on the agenda is to extract all the modules! NOTE, I am not going into detail on the safety aspects since they will differ from country to country. 400VDC can kill, always get certified (SFS 6002 in Finland), attend safety trainings and use the correct safety gear when dealing with high voltages.

    Leave a comment:


  • eTiMaGo
    replied
    I used to spend a lot of time racing electric RC cars, and this thread somehow brought a lot of memories! Fascinating how many of the concepts are the same, just on a WAY bigger scale!

    Leave a comment:


  • Kaktus
    replied
    Neat wheels, suits it really well! The wheel centre cap is also a neat touch, will be interesting to see the finished product.

    Must say it is rather fascinating to see you resolve various issues with your Leaf, you do make it look very easy!

    Leave a comment:


  • Dala
    replied
    So let's talk wheels. Winter is long over and it's time for summer tires. This is the first car I've owned with a Tire Pressure Monitoring System (TPMS). I got a new to me set of alloys, and naturally wanted to keep the TPMS functioning. First order of business was to order another set of pressure sensors, but the local Nissan dealership had these for 100€/sensor! So ebay was naturally the next place to look, and for 17€/sensor I won't complain.

    Here are the wheels fitted, stock Bridgestone Ecopias, 16", 17.1kg rims. The exact same weight as the OEM steelwheels, so not very high quality rims these. But they look better than the steelies


    So, let's tackle the TPMS warnings. The Leaf warns you about the TPMS on both the lower and upper instrument cluster. It also flashes them for a solid few minutes, so you'll definitely notice it and want to fix it asap!


    The solution is LeafSpy Pro. The instructions are so simple that anyone can remap the sensors. It took me 10 minutes!


    After getting the car to accept the new sensors I let it cool down for 30mins. Then I filled the tires up to the eco-miling spec of 3.1bar front, 3.0 bar rear. Instrument cluster is happy again!


    My 3d-priting obsession continues, I wanted to personalize the wheels, so 3d printing center caps seemed like a perfect tiny project.

    Started by modelling this "Toyota Prius Wheel Center Cap - Power Symbol" https://www.thingiverse.com/thing:44003 to fit my wheels, made new hooks. It's so easy to model, using sketchup since it's free.


    Printed a prototype, worked almost too good, now to print more in higher quality and paint them


    I promise I'll get back to the CAN stuff soon, just wait

    Leave a comment:


  • Dala
    replied
    Thanks guys! And now for something completely different.

    My friend Johan was bitten by the 3d-printing bug, and I am so intrigued! I searched thingiverse for a J1772 holder, and found this simple design:
    https://www.thingiverse.com/thing:2481870

    So I sent him a message, and little over an hour later, a prototype was printed.

    Started


    Finished


    I was told this was a really fast prototype (Layer-height was 0.3mm), and if I wanted a better looking one it would take roughly 4.5h to print one. I am so excited by such a small piece of plastic Thanks Johan

    Leave a comment:


  • ewat
    replied
    This has been a rollercoaster Dala, I love this thread!

    Leave a comment:

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