My analysis of the firmware update to my Leaf

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.

TomT

Well-known member
Joined
Aug 8, 2010
Messages
10,656
Location
California, now Georgia
Note: There are numerous updates toward the end of this post...

Today I finally broke down and had the software update done to my Leaf. Below are a few observations of the process and result:

The dealership had a large glass window overlooking the service bays from the waiting room and as luck would have it, the Leaf bay was directly behind it so I had a ring-side seat of the whole process.

After they drove my Leaf in, the tech plugged the computer in to the interior datalink connector (he had not opened the hood or charge port at this juncture.) At that point I am not sure what he was doing but it took about 15 minutes before there was any additional progress and he appeared to be consulting with some other folks in the shop... He apparently was either through or not that familiar with the process as he had about a dozen page manual that he was going though page by page as the process continued.

At this point he opened the hood and hooked a battery charger to the 12 volt battery. This is apparently to insure sufficient voltage during the flash, much as one does when flashing the bios on your laptop computer. He then started the actual update process which appears to have taken about 15 minutes.

When he was done, he unplugged the computer from the interior connector and went for a test drive (about 1.5 miles on the odometer as it turned out). He then came back to the bay, opened the charge port and plugged the car in to charge. About 15 minutes later he unplugged it and sent it off to be washed. Why he plugged it in I'm not sure since 15 minutes of charge would make no real difference but perhaps it was just to insure that it WOULD still charge... Time from when I drove in to when I drove out was two hours.

What I noticed before and after the update:

I had charged to 100 percent the night before. The trip to the dealer is about 3.6 miles and is all downhill so I arrived with an essentially full battery (I had only one circle of regen available which tended to confirm this.) When I pulled in I was showing 92 miles of range in D and 102 in ECO, and 12 bars.

After the update, I had 11 bars showing and 86 miles in D and 96 miles in Eco (the range may have changed partially due to the way the tech drove during the test drive and not been a result of the update - I have no way to know). So, it appears that I lost one bar when I got the car back bar and about 10 miles of range. What was also interesting was that it was showing that I could gain 24 miles by turning off the climate control even though only the fan was on and it was showing no power usage at all on the energy display. This, of course, was bogus and, in fact, turning off the CC completely did NOT give the promised 24 mile increase on the range display.

As I headed off to work, the range started to climb up and the miles gained by turning off Climate dropped. At ten miles from the dealer I was up to 105 miles and 12 miles to be gained. This is all in ECO mode. At 15 miles I was up to 108 range and 8 miles to be gained. By the time I pulled in to work, I was at 111 miles and +1 mile to be gained. This is about 10 miles less range than I am used to seeing under this same conditions to work. So, it is clear to me that the system had to relearn the driving and climate control characteristics after the upgrade, and recalibrate itself. It appears that its data was scrubbed by the upgrade. It also appears that I have "lost" about 1 bar and 10 miles of range with the new software under identical conditions.

One interesting phenomena that I observed, which I have never seen before, occurred on the downhill side of the one big hill I have to climb and then descend. As I was descending and regenerating (about 10KW worth) I went from 8 bars to 9 bars of SOC. I have never before gained a bar when regenerating down this hill (or any other, for that matter)...

As other reported, my timer had been turned off and I had to re-enable it. This may be done on purpose by the upgrade process to facilitate the charging of the car and checking of the charging system by the tech after the upgrade.

Looking at the diagnostic display, I see no change in any of the version numbers before and after. I was at part number A before and I continue to be afterward. Thus, it appears that there is no way to really tell what software version your car has from that display.

I have a lot of driving to do today and expect to arrive home with a pretty much exhausted battery so it will be interesting to observe the behavior at the lower end of the SOC compared to what I am used to, and where the warning(s) come on...

Update at 9:30pm: I drove a total of 90 miles today and arrived home with 6 miles range showing and 1 bar (I circled the neighborhood a while to get to this point). The low battery warning came on about half way between the point when the range changed from 9 to 8 miles and then changed from 8 to 7 miles. Previously it came on at about 18 miles. I'm not going to charge it tonight and will circle a bit later this weekend to see where Turtle Mode now kicks in...

Update the next day: I had 5 miles range remaining when I turned the car on (down from 6 when I turned it off the night before). I drove in D in a loop of flat, uphill and downhill terrain near my home. After 6.9 miles, it went to dashes and I got a very low battery warning. The last bar also extinguished shortly before this point. I drove to the top of my cul-de-sac and drove for another 7.3 miles before it went in to turtle mode. I continued to drive the circle for another 2.1 miles before it shutdown at which point I coasted back down the hill and in to my garage. So, clearly they have built a lot more hidden reserve in to the system to preclude all but the most adamant from running out of battery. It would appear that they have shifted everything down about 10 miles. Armed with this information, I can now recalibrate my own mental SOC and range to empty calculations and know that I can safely drive much further in to the lower limits of battery charge than before. I will charge to 100 percent tonight and report the power used to do so tomorrow.

Final update the day after: I charged to 100 percent last night. TED showed that I used 26.37 KwH to do so. Assuming a 90 percent efficiency, this is pretty close to the claimed 24 Kw battery capacity.
 
Yep, I noticed the same behavior in low battery conditions. Several other LEAFers reported similar results.

http://www.mynissanleaf.com/viewtopic.php?f=31&t=3473

On my side, before the update I was trying to estimate the usable battery capacity by using the miles driven, estimated remaining and mileage and averaging the results. After the updated it looks to me that they moved about 1.5KWh of energy to a "hidden reserve" area below the last SOC segment. I think they didn't change the threshold of the first low battery warning which is why it now comes out at 8 miles instead of 13-14 before the update.
 
It was an interesting and fun experiment, and definitely gave me a much better idea of exactly what I have to work with in terms of usable range. What we need now is to redo the SOC versus bars graph that was done sometime ago to represent the new firmware calibration... And of course, we still need a REAL SOC meter!

ericsf said:
On my side, before the update I was trying to estimate the usable battery capacity by using the miles driven, estimated remaining and mileage and averaging the results. After the updated it looks to me that they moved about 1.5KWh of energy to a "hidden reserve" area below the last SOC segment. I think they didn't change the threshold of the first low battery warning which is why it now comes out at 8 miles instead of 13-14 before the update.
 
you recharged at 26.3 Kwh, i would take 85% as your efficiency which gives you 22.3 Kwh which is more in line with what others have seen
 
mogur said:
Final update the day after: I charged to 100 percent last night. TED showed that I used 26.67 KwH to do so. Assuming a 90 percent efficiency, this is pretty close to the claimed 24 Kw battery capacity.
Nice. @85% we get 22.7 kwh.

Did you note the m/kwh that Leaf showed ?
 
Just a comment to the OP, I'm not sure if anyone posted the PDF to NTB11-038 yet since I haven't read all the other threads, but you can should be able get TSBs for the Leaf at http://x.nissanhelp.com/forums/Knowledgebase.html?catid=652 instead of paying for a subscription on nissan-techinfo.com. Unfortunately, NTB11-038 isn't up yet.

Also, http://x.nissanhelp.com/forums/leaf/18915-nissan-leaf-technical-information-manuals-bulletins-recalls-campaigns.html might prove semi-useful.

I've gone to Nissanhelp.com or a few other sites for Nissan TSBs in the past.
 
Back
Top