Sponsor Banner Go Fast Bits Castrol Edge Super Cheap Auto Haltech Bridgestone RE003 Ryobi Tools Century Batteries

Announcement

Collapse
No announcement yet.

Dala's Leaf buildthread (2015 Nissan Leaf)

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • 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!

  • MHR1294
    replied
    I didn't know there was only 3% between A and B! That's useful info for me The winter tyres on my Alto are B rated I'm sure of it.

    I drove an electric car for the first time at work the other week, it was a Renault ZOE. it's actually not weird to drive at all. I really liked it.

    That's good to make a charging point public! Nobody would ever do that here in the UK, they're all so selfish. lol

    Leave a comment:


  • Dala
    replied
    Originally posted by MHR1294 View Post
    So Italy cells are better? Maybe they've been subject to the Italian equivalent of the Italian Tune-up!

    I guess untested cells is too risky - they might be better but it's the "what if it isn't" that will be eating you?
    Yes, most likely gonna chuck in the Italy cell any day now, just waiting for the weather to turn completely.

    Status update on the Leaf. It's been cold here...

    I assembled the OpenEVSE unit. Now I need to decide where I mount it. I will most likely make it open to the public on all charging apps, since it probably goes in the middle of nowhere


    We have also had a fair bit of snow


    Due to all the cold and snow, I decided to get some proper snowtires instead of the all-season ones that came with the car.

    I settled on "Nokian Hakkapeliitta R3"
    in the format: 205/55 R 16 94 R XL


    This is the tyre that Nokian primarily recommends for electric cars, since it's a low rolling resistance and wont impact the range. On the sticker they are branded as B on the economy gauge. The efficiency step between A - B - C goes something like 100% - 97% - 90%, so there is a huge benefit from stepping up from C to B. From B to A the 3% efficiency step is not as noticeable.

    Leave a comment:


  • MHR1294
    replied
    it was only -5 here yesterday and we had some frozen rain. My mirrors nearly didn't fold out so I've left them out so they don't jam in the morning.

    So Italy cells are better? Maybe they've been subject to the Italian equivalent of the Italian Tune-up!

    I guess untested cells is too risky - they might be better but it's the "what if it isn't" that will be eating you?

    Leave a comment:


  • Dala
    replied
    Car is working fine in -21*C Hope it doesn't go towards -30 this winter...
    I now have some capacity numbers to share, and time to make a decision.
    Test, 5Amp discharge, from 4.1V -> 3.3V
    USA cell: 39,77Ah
    Italy cell: 43,30Ah

    So presuming I have an USA cell from the same batch, If I upgrade to the Italy cell, I'd get a 9% range increase! I could also try looking for better cells, but most people just sell untested cells :/ Hmm...

    Leave a comment:


  • MHR1294
    replied
    that looks like an excellent tool!

    It's going to get you exactly the results you want, which is ideal

    Leave a comment:


  • Dala
    replied
    This showed up in the mail.



    Now I can start capacity testing the big Leaf cells! I settled on the reasonably priced Antimatter charger/discharger. It can do 10A charge and 7A discharge. I started it a bit more gently, and the test is going to take some time. I set the upper voltage to 4.1V, and discharge down to 3.0V. If I had set the upper voltage to 4.2, it would ofcourse net more capacity, but as long as I do the same for each cell I test, I will come to a conclusion what cell would be best to use in the car.

    Leave a comment:


  • Dala
    replied
    Thanks
    The LED was bright enough for pitch dark Finland atm

    I finally caved in, and started renting a garage space 200m from the apartment. It costs 50€ per month, with unlimited electricity. This solved my range anxiety issues permanently. I am limited to 8Amp charging, but that is OK, I only need this space once or twice a week. I should have just done this from the start


    Now I can start to experiment with the timers properly before going on a long trip!

    Oh, and here is a snip of a LeafSpy screenshot, showing the consumption during prewarming.


    On 21*C, with fanspeed on 2, it makes the cabin nice and warm in a matter of minutes. Consumption hovers between 1500-1800W in this state. Green is going in, red out.

    With the 16A charger (3300W), you can charge the battery and still preheat the cabin. Awesome!
    With a 8A charger (1600W), if you preheat, all electricity will be pulled from the battery, and the charger barely keeps up replenishing it.

    Some people on the nissanleaf forums have even reported SoC dropping a few % when preheating, this is probably only in USA where they have only 110V, and a normal L1 charger would only output 1000W+-200W. Thanks EU for 240V

    Leave a comment:


  • cubic_nz
    replied
    I found this type of LED was not bright enough, so I built a custom upgrade using a paperclip and some solder
    20181224_142820.jpg

    Leave a comment:


  • SBC
    replied


    I will just leave this here.

    Yesterday we managed to burn a battery-body ground wire from 1970 cadillac (It was literally in flames), so I don't see myself working on cars which works only with electrics.

    Leave a comment:


  • Dala
    replied
    Happy holidays! The Leaf is happily churning out spruces as I drive, very festive


    I am continuing the LED upgrade, here is the boot space lamp


    And here is the dome light. Both got 31mm wedge LEDs.


    I need all the range I can get now. When the cold hits this hard -12*C, the effective range falls down to 60km-ish. It is such a shame that I cannot prewarm it anywhere, if I could the range would be so much better. I noticed that if I prewarm it and charge right before leaving, the range is the same as autumn.

    It is also quite hard to wash the car at -12, here is what happened when I started the pressure washer :P


    But after heating it in the garage, I could wash and wax it properly


    Oh, and this came in the mail. More on this later

    Leave a comment:


  • MHR1294
    replied
    half a meter more!?

    Nah, I think you'll go 3/4 of a meter! hahaha

    This is when you find out the disappointment that the 30 means it was his 30th battery or something. I hope not though.

    Leave a comment:


  • Dala
    replied
    So Christmas came early, and the previous owner sent me an identical cell from the batch he used to 'fix' the car. It is from USA and has 30 written on it. If I were a betting man, I'd say that the 30 stands for 30Ah measured on one 4V cell. That would be a 33Ah->30Ah, 90.1% degraded cell, which makes sense. I will have to measure it myself to make sure. But at least now I can take a rough reference without taking the car out of service, and compare it against the Italian cell.


    What a complicated origin story, kudos if you are still following the thread

    On a more interesting note, I did another tweak. I intend to switch all incandescent bulbs over to LED to save some electricity. The 10W license plate bulbs got swapped over to Osram 2W LEDs.


    Yellow incandescent on left (although my phone made it way whiter that it actually was), LED on the right

    Doubt I actually get any more range with this mod, maybe half a meter more?

    Leave a comment:


  • MHR1294
    replied
    Charging infrastructure here is going crazy! we're putting chargers in the middle of nowhere hahaha

    Leave a comment:


  • Dala
    replied
    So I've now driven 600km with the leaf, might give you guys a status update.

    The charging situation is not ideal to say the least. Neither my apartment complex nor workplace wants to let me charge. So this leaves me with only public charging places (3x in my city) and the occasional visits to parents. Sometimes the public ones are temporarily unavailable (broken/occupied), so I am certainly paying the early adoptor tax. Not impossible to live with, but if you don't have home or workplace charging, I don't reccomend getting an electric car frankly.

    So let's improve the situation. The Nissan branded charging cable that came with the car charges at a measly 8Amp. This roughly translates into 8km per hour added to the battery. This makes family visits long, since I need to spend ca 3-6h charging when visiting. Since that is way too much family time, I purchased the chinese Duosida 16A EVSE. It costs 200€, so quite cheap! (Original Nissan charger costs 800€!)


    It works in exactly the same way as the stock one, but instead it draws 16Amps when charging. 16A is quite a lot from 240V AC, so you need to be careful where you plug this charger in, if it's a 10A outlet for instance you will trip the fuse. This cuts the charging time in half, so now I only need to spend 2-3h charging!


    I haven't had time to measure the capacity of the Italy cell, so I just put a small load on it to make it closer to 7V resting voltage, which is way better than the 8.2V it shipped with.


    So to summarize, love the car, hate the charging infrastructure. Man I would like a parking spot somewhere!

    Leave a comment:

Working...
X