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Post by rusdy on Jul 15, 2019 12:06:57 GMT 11
Hi all, Does anyone have any details on how LeafSpy (I use LeafSpyPro) measure the Wh used in its app? My kWh/km figure from the LeafSpy is different from the one reported by the dashboard (I'm using 2012 Leaf). The difference is quite large, and I need the remaining kWh figure to be accurate so that I can predict remaining range accurately (as my 2012 Leaf battery degraded as expected). Every kWh is valuable (which worth 7 km per kWh!!). In the example I have from this morning, according to LeafSpy, I have 7.6kWh remaining on my battery (4.6kWh used). However, if I use the 0.15kWh/km figure from the dash (reset at the same time at the start of the trip with LeafSpy), I should've used merely 3.5kWh only, which means I should have 8.7kWh remaining instead. What I've found interesting from past experiments, as I deplete the battery further to empty (under 2kWh remaining, i.e. VLBW), the remaining kWh figure paused (but the used kWh still grows). As if it's playing catch up with the difference. Hmmm... :?: Figures that I've used:
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Post by johnmath on Jul 16, 2019 18:57:59 GMT 11
I have a 2016 Leaf which shows consumption as km/kWh, not kWh/km. We typically get between 7.2 and 7.5 km/kWh, which equates to between 0.14 and 0.13 kWh per km. The the consumption meter in the car shows the average consumption since last reset and in our car you reset the consumption meter by pressing and holding the button with the black dot on it for one second while the consumption meter is being displayed. Are you reseting the consumption meter and not just the trip meter? Personally I prefer to look at the battery charge % display to get an idea of the practical remaining range. I find the "Driving Range" number displayed on the dash rather waffly.
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Post by rusdy on Jul 17, 2019 11:49:18 GMT 11
Hi johnmath, yup, it was reset at the same time (so it shows --- in the beginning). My observation so far (which maybe incorrect): - The remaining kWh value (7.6kWh figure from my screenshot), as per LeafSpy manual says, calculated from GID (which is taken from Leaf's onboard computer), i.e. 98 * 77.5 = 7.6kWh. The '98' figure is also in my screenshot (top right);
- To get Wh used during the trip (i.e. the 4,691Wh figure from my screenshot), the LeafSpy calculated this, i.e. 12.3 - 7.6 = 4.7kWh (matching!). The '12.3' figure is taken at the start of the trip from LeafSpy, which I didn't upload;
- Leaf's dash Wh/km figure is taken directly from battery's current clamp, i.e. pure consumption figure (includes auxilaries).
Regarding point 2 above: This is where I'm not sure whether this figure is calculated or taken from Leaf's onboard computer, as LeafSpy also has a mode to calculate regen Wh, which means the figure should be taken from car's computer as well? Regarding point 3 above: I'm guessing this, as how come consumption figure (in Wh) is wildly different between LeafSpy and car's dash? For the same 24km trip, LeafSpy reported 4,691Wh, where as according to the dash, it's (0.15kWh/km)*(24km) = 3.6kWh. This is where my saga started (hence, this thread), i.e. which figure to take? As this effects the accuracy in calculating remaining energy in the Leaf's battery. Again, the only reason I do this is due to my dilapidated battery. Knowing accurately remaining kWh is so valuable to plan 'long' journey!
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Post by rusdy on Oct 4, 2019 15:06:59 GMT 11
Inspired by seb 's post here regarding measuring battery capacity at the wall, I've done mine trying to circumvent this differences in kWh measurement (in order to get accurate remaining charge). So, from 80% charge, my experiment data: - Travelled 65km;
- Dashboard indicated 0.11kWh/km at the end of the trip (after reset at the beginning of the trip);
- At the end of the trip, LeafSpyPro indicated 4.1kWh remaining (from 12.2kWh at the start);
- After charging it back to 80% overnight, consumption at the wall is roughly 8.5kWh (figure taken from my Tesla PW2 app)
From the above actual data, here are my total consumption (for the 65km trip): - According to dashboard: (65)(0.11) = 7.15kWh used.
- According to LeafSpyPro: 12.2 - 4.1 = 8.1kWh used.
- According to PW2: 8.5kWh used (to mention the obvious, this includes 'wall to wheel' inefficiency).
Long story cut short, the dashboard energy economy is more accurate than the data from LeafSpyPro. Note: - LeafSpy 'kWh' figure is taken from 'GID' data, from the onboard Leaf's computer;
- 7.15 / 8.5 = 84%, which is more realistic 'wall to wheel' efficiency.
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seb
Half Charge
Posts: 62
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Post by seb on Oct 23, 2019 11:10:50 GMT 11
I've inspired someone. Woohoo!
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Post by rusdy on Apr 9, 2021 18:33:09 GMT 11
For battery geeks out there, I've compiled all data I have so far in a single graph, i.e. comparing before and after battery replacement. The degradation path looks super bad at the moment, so I'm hoping it slows down eventually (as reported by other users such as Feng and other users from facebook that they have much better degradation compared to old battery): Also, continuing this thread, the difference between dash and LeafSpy reading is far less compared to before. More battery data: click here.
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