Level 1 vs Level 2 - Full Charge

[Pipcecil]

I am helping a friend troubleshoot a problem with his Leaf. Starting in a couple of months ago, his range on the leaf drop dramattically from a standard 80 miles per full charge to 65 miles per full charge. I would have attributed this to higher AC usage in the blearing Texas heat (I have noticed a drop in my range as well), but in comparsion to myself, I haven't experienced anything this dramatic and this quickly. My friend had his battery checked at the nissan dealership who reported no problems. But the nissan leaf tech recommended a Level 1 charger vs using his level 2 charger to get better range. This puzzles me as both pull the same amps, with the level 1 pulling ~2/3rds less wattage. I don't see how a level 1 trickle charge could get "fuller" charge on the battery. Is there anyone more tech minded than myself that could shed some light on this?

Regardless of the level 1 vs level 2, he still has the issue with the sudden decrease in battery power. Here are some potential identifications of the problem (some mine, some his)

1: Heat affecting the battery: Its been over 100+ for 40 someodd days here, and he chargers in an unisulated garage, reaching temps as high as 120 inside the garage. Despite this though, his battery temp gauge only registers 7 bars

2: Something wrong with his charge and the cell balancing. The level 2 is not providing an accurate cell balance when charging (the onboard charger is responsible for this regulation?)


3: Under representing the affect his AC is really having on his range. It really could just be that hot and its dragging his range down.

Any ideas or suggestions would be helpful. I know there are some engineering gurus who could trouble shoot something like this and give some ideas on the potential problem.

 

[smkettner]

Can you swap cars for a week to eliminate driving habits as the differential?
Or swap cars and follow the same route one day to compare.

 

[Stanton]

Can you swap cars for a week to eliminate driving habits as the differential?
Or swap cars and follow the same route one day to compare.

If possible, that's an excellent idea. However, the comment made by the Nissan tech about "L1 vs. L2 charging" concerns me, and would lead me to believe that he doesn't know what he's talking about. In other words, I wouldn't necessarily believe there WASN'T a problem with battery pack (whatever that may be--cell balancing, bad cell, etc.) and he just doesn't know how what he's doing. I would get a second (technical) opinion.

 

[TomT]

Another Leaf "tech" who does not know about what he is talking! I swear that Nissan's own people do more to spread mistruths than all the outsiders combined...

But the nissan leaf tech recommended a Level 1 charger vs using his level 2 charger to get better range.

 

[AndyH]

I am helping a friend troubleshoot a problem with his Leaf. Starting in a couple of months ago, his range on the leaf drop dramattically from a standard 80 miles per full charge to 65 miles per full charge.

Is the range drop actual range/range remaining according to the 'fuel gauge' or is it a drop in the range estimate display?

 

[Pipcecil]

The range is a drop in actual bars (not from the guess-o-meter). My friend is constantly getting less. Lately I have been trying to do some "testing" on my own. I know my friend most drives highway miles (I don't know what his speed is), but here in the texas heat I have been getting less on my full highway trips running at almost 70 miles on a "full tank". Considering if his highway speeds were greater than mine (it was mostly 60 with some 65) I can easily see a range drop to 65 miles of full range in his car now.

After looking at everything it has to be the heat and AC usage. I don't believe the car battery is high enough to cause range degridation (he registers 7 bars) and, as everyone has pointed out, the charging level (1 or 2) wouldn't affect his "full capacity". Finally even beyond the unintellegent Nissan worker, the battery diagnostic came back ok, which should have caught a cell imbalance.

39 days of over 100 can really make that AC unit work hard. After all is said and done, i think thats going to be the final answer, although he probably won't listen to me. I am assuming his "instant" drop in range one day was more gradual and he just finally paid attention to it. I will point out that the additional AC usage estimate on the screen (X miles if you turn climate control off) is TOTALLY WRONG for AC usage. I use 4 bars (pre-cooled, Auto AC set at 78) to get to work and 5-6 to get back home (no pre-cool, auto AC at 84) all the time the readout says I would only get back 2 or 3 miles if I turn off the AC. So, the working AC in 100 degree weather without pre-cool results in an easy 1-2 bars of loss (8-16 miles if we use the bar estimate).

 

[ralphmc]

L1 charge has the advantage of charging slower - so the battery management has an expanded window of time to equalize the SOC on all modules -

Out of past advanced battery experience I had my first 5 charges done to full 100% charges using the L1 charging process, and not regretted the 6+ m/kWh I am getting out each on about 50 mile round trip home to work and back.

Ralph

 

[EVDRIVER]

Something tells me this is all driver perception and the car is functioning fine.

 

[AndyH]

... After all is said and done, i think thats going to be the final answer, although he probably won't listen to me.

You may be able to 'confirm' the significance of driving style differences by comparing your guess-o-meters. Point out to your friend that their right foot is much more important to range than even the AC system.

My old VW diesel can deliver both 28mpg and 50mpg. Same thing for my electric motorcycle - I can ride for 38 miles or 65 miles on a full charge. It's all about how I choose to drive.

Good luck with your education attempts!

 

[Pipcecil]

I think, after everything, I finally figured out what the problem is/was. Everything seems to match dead on too. So here are the facts:

A very noticable drop in range
Happened abruptly around the beginning of June (I think he said the 5th or 3rd)
Does lots of highway driving

Yesterday morning, despite being a more near normal temperature for once, I wasn't really using my AC at all. This is the first in a long time, and I was excited to see if I couldn't pull more range out of the car today. My drive is very predictable and the guess-o-meter always comes up +-5 miles at the end. I also know when ear bar drops off my range. Despite the easy temp morning, my range was -10 miles on the guess-o-meter and, for the first time, I used 5 bars instead of 4 to get to work! I didn't understand it until I really thought about it. I had an easy drive in this morning, I hit every light green, no traffic on the majority of the route, and the portion that ALWAYS has stop and go traffic for about 5 miles, I was able to sail through at 60 for 90% of that stretch. Then I realized that the traffic (i.e. the stop and go, espcially on the highway) was maintaining my range versus me burning electrons going 60 mph. Then it all came to me to solve my friends problem:

My friend is experiencing less traffic. Around the beginning of June, school its out, supply a reduction in traffic, and in some areas, a siginificant reduction. Add that to highway driving, i.e. being able to go 60ish versus a normal stop and go (or even less stop and go where you can accelerate more) and it all fits. yes the heat plays a part but not that much, its the speed and the traffic. I think we all know, when planning a trip to give our range less if there are highways, but I guess we forget about it when our normal trip all of the sudden is using more battery power.