New to me low mile 2017 with poor range?

My Nissan Leaf Forum

Help Support My Nissan Leaf Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
LeftieBiker said:
If he wants to see Turtle without risking bricking the car, any high battery load at low SOC should cause a DTC event. I suggest driving under full power up a substantial hill - carefully. IIRC, these kinds of events cause a warning message but don't strand the car, once the extra load is removed...

Exactly. OP should be able to find a hill around Boulder :)
 
A further realization about leafspy showing 37% vs car showing 7% is that explains the missing energy - I was earlier doing math showing the 4miles per kwh didnt line up with a 25kwh battery and the miles to low % - but if car saying 10% means there is really 40% the missing power is still in the battery. It also implies if I look at charging Im probably only putting in 16-18kwh in a full charge or so
 
By "bricking" the car I just mean leaving it in a state where it needs a charge to move again, as opposed to 'dead as a doornail'. Turtle mode reduces power drastically, but the car will still drive - at very low speeds unless you are going downhill. It's just that how long Turtle stays, before giving way to Stopped can be hard to predict - the state of charge display changes to "---" when you get to the mid single digits. LeafSpy can keep giving you state of charge in "Gids" (very small units of charge) but without that you don't want to be turtling around far from home.
 
derbartman said:
A further realization about leafspy showing 37% vs car showing 7%
The cell voltage histogram can kinda sorta be thought of as a proxy for a cell energy histogram

A fully charged, healthy pack is ~ 4.1 volts * 96

LeafSpy is adding up the voltages of 96 cells;
The car is multiplying the voltage of the weakest cell * 96

---
Load causes a voltage sag, and this effect is all the more pronounced as the cell SoC is lowered. If the voltage delta between the weak cell and an average healthy cell is 280 mV *at rest*, the delta is much greater under load. Thus the advice to expose the weak cell by using a hill. You can also park the car in a quiet place, put one foot firmly on the brake and progressively press down on the go pedal with the other foot. Virtual hill, at your service. Do it with a low pack SoC of 10 - 20% until the car complains with alerts and amber lights. Then you have your DTC.

The Nissan dealership will 'understand' you better when you can say "this car loses power and goes into Turtle Mode when it goes up a hill when the starting SoC is under X%. It is UNSAFE to drive."

---
Turtle mode is the car restricting power to protect the battery, AKA not letting the driver induce additional voltage sag in an energy depleted cell.
 
You can also park the car in a quiet place, put one foot firmly on the brake and progressively press down on the go pedal with the other foot. Virtual hill, at your service.

Virtually all EVs - and I believe this includes the Leaf - cut off motor power when/while the brake is activated, and usually switch the circuit to regeneration. However, it may well be possible to do the above using the foot-operated parking brake only. The electronic parking brake, if so equipped, releases automatically, at least in the 2018+ cars.
 
On a recent drive nearing my house with a lowish SoC I accelerated strong and saw leafspy report a delta of something like 440mv - but no code or shut down yet
 
derbartman said:
On a recent drive nearing my house with a lowish SoC I accelerated strong and say leafspy report a delta of something like 440mv - but no code or shut down yet

Give it another nudge. ;)
Either a bit lower SoC, harder throttle, or longer test.

Or:

I mentioned earlier that the BMS enters Turtle Mode when any cell reaches ~ 2.6V
So once you are at ~ 3.1V in the weak cell during normal driving, your above stress test should turn your car into a turtle
 
I think I got a semi straight answer from the dealer that they needed the code to happen but the head tech implied he expected it to happen soonish given our info.
Wife has been commuting with it - suffering through not using much heat for fear of not making it home even though I have encouraged her to just use it.
So far no code..
 
Last night the car started with full charge and the yellow warning light - and then turtled still with > 96 predicted miles -

Leafspy shows one cell ~3.83 and all the rest around 4.03 : 213mV

The leaf sure isn't very clear about what is the problem and my blue tooth OBD reader and app seem to not be able to get a regular reading and the device turns off too..

I guess I will get to take it in to dealer - too bad I came to that conclusion after service closed on Sat..
 
In dealer today - they also see the bad cell - they say they need to do a more complex battery test - drain it 0% then charge 100% - so Im out a car for tonight. They also claim that even if its a warranty replacement Nissan only pays for 3 days of loaner - so if the part is going to take a week Ill have to choose when I want my 3 days..
but apparently we will know for sure the plan tomorrow
 
Ok - Boulder Nissan today told me that they are replacing the module so unlike other stories of the past and in the UK this dealer at least is authorized to replace modules inside the battery pack and that is what Nissan US told them to do. New module in 2-4 days and then work is 3 days or so ? IDK why replacing one of those is so long - I sure wish we were getting the 40kwh - but either way this should make a huge difference for the car and having it work like we thought it would to start with will be a big win. Being without a car for 6 days not so great. Apparently Nissan will only do 3 day rental for warranty regardless of length of time waiting for part and work - then today they said 4. Im not sure how that is - it could take them a month to do it, but they give 4 day loaner - but Im going to try an not bother with the hassle.
 
Us too for sure. I guess I wonder if a consumer in my situation would have been more likely to get a new battery pack if one were to locate a dealer which was not certified for module/cell replacement..
oh well - will be pretty dang happy if it works as well as should have all along
 
Possibly but I'd guess that most replacements packs are replaced since all the cells are bad. The cells probably all come from the same manufacturing batch so that they age equally. If that batch is bad then all the cells are bad and the pack needs to be replaced. If just one module is bad, then it's obviously cheaper for Nissan to just replace that module. The balancing system will need to keep the new cells within the voltage range of the older cells but so far that hasn't come up as an issue yet, AFAIK.
 
well - IDK if its obvious its cheaper - ya it generally makes sense - there are fairly convincing posts on various boards of people with singular or small number of bad cells receiving new complete batteries - in fact the 40kwh -- but I hear y - makes sense to me - if a you tuber can replace a single module then surely the techs at nissan should be able to. but if it takes a tech 3 days to do it - what is shop time? x24 maybe $150?
but then again maybe a big chunk of that is getting to the battery at all. Also there are quality and such issues -
Also - cheaper isnt the whole picture for all this stuff - maybe there is work hazards - maybe risk to building etc..
 
derbartman said:
Us too for sure. I guess I wonder if a consumer in my situation would have been more likely to get a new battery pack if one were to locate a dealer which was not certified for module/cell replacement.
That would be my thought, but the flip side might be even more difficulty getting the dealership to understand the problem.

Congrats on getting this repair
 
Ok - after Boulder Nissan having the car for 8 days we picked it up today. I asked if they had done the deep battery test like the one which allowed them to trigger the replacement and they didn't know. Already we know from the return drive and battery use it is way better. Once I was home I took this shot from leaf spy:
IMG-6430.png


Also this link in case someone wants to support them by going to their page and getting ads: https://ibb.co/dBNWctq

I guess Im sort of bummed my brand new module seems to be worse/weaker than my 17k mile 3 year old rest of battery.. but glad we have a real battery now.
 
If they didn't properly charge the new module before installing it, then it may just take a while to get up there with the rest of them. The BMS can't move large amperages.
 
I would run the battery down to 5% SOC or so, then do a full L2 charge overnight to get the BMS to balance the cells a bit more. However, a 26 mV imbalance isn't that bad anyways.
 
Back
Top