Strange readings - GOM more accurate than SOC bars.

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adric22

Well-known member
Joined
Apr 23, 2010
Messages
2,488
Location
Fort Worth, TX
I know there have been endless discussions on this forum about the GOM. But I've had my Leaf for over 3 years and 30,000 miles and this is the first time I've seen this.

I'll start out by saying I lost my second capacity bar a week or two ago. I only lost the first bar a few months before that. So it is weird that I went over 2 years with 12 bars and now I've lost 2 rather suddenly.

However, here's the weird thing. I drive the car mostly to work and back and other short trips, usually less than 10 miles before a recharge. It's pretty rare I take the car out on a longer trip, especially since the weather got cold. But I needed to go to my brother's house yesterday which is about 25 miles one direction, almost all of the way is freeway. I have made this trip many times before, just not recently. Add to that, I have made the trip in our Volt one time and managed the entire trip on battery power.

So I arrived at his house yesterday and the battery SOC bars had dropped to 4, suggesting I had less than half of my range still available. However, it showed on the GOM that I could go 37 more miles, which is more than the 25 I needed to go. I could have charged at a nearby station, but I wanted to see if my capacity was really that low. So I decided to drive on home. I figured if it didn't make it, I'd call Nissan roadside assistance and have it towed. I really needed to know if the car had lost that much capacity that I could no longer make a 50 mile trip in good weather conditions.

So, to end the story, I arrived home with 1 bar remaining on the SOC bars and the GOM still reading 23 miles remaining. There had been no battery low warnings or anything. In the past when I've seen just 1 bar left I usually have less than 10 miles remaining and would have gotten a battery low warning. It is strange that I consumed 8 bars on the trip there, and only 3 on the trip back.

I'm wondering if my car just needed to get a deeper cycle to get things calibrated again. I noticed when I got into my car this morning the GOM showed 85 miles of range, which is the highest I've seen in ages. Normally it shows around 65 miles in the morning on a full charge.
 
Hmm 23 miles with one bar seems way off. The most I have ever seen (when car was new) at one bar was maybe 10 or 11, there could have been a 12 there at one point. I have notice sometimes a phantom bar dissaperance - i.e. I am driving and 2 bars go away at once (ek!). Its quite startling. My first guess is that

A) for some reason you did (or the car thinks you did) drive at like 5 miles an hour for a long enough time to change the GOM that much - but I seriously doubt it
B) cells could be out of balance
C) one of your cells could be going out - i.e. like a bad connection you lost it and then it reconnected and you gained it back at the end
D) a werid software annomally/fluke

Either way I would let the car rest and charge to 100% to recalibrate (and sit there for awhile) and just watch for future behavior like this. This should take car of all but C. If there is an actual problem, a battery test should find it (yours is up in a couple of months, right?)
 
Oh.. I also forgot to mention that when I plugged the car in, it had regained some 35+ miles of range in just two hours of charging. And the SOC meter was around 8 bars, I think. This should be impossible for my 3.3Kw charger. Again, suggesting there was more power there than what the car was reporting.

I am actually going to be meeting up with somebody tomorrow morning in Grapevine who will be hooking up their Leafspy to have a look at my car. I'll report back what was found. However, yesterday's experience makes me a little more comfortable about the long drive from Kennedale to Grapevine in the morning.
 
planet4ever said:
[*]Any change in elevation between your house and your brother's house?
[*]Was the wind blowing?[/list]
That thought had already occurred to me, and there may be some elevation change, but it wouldn't be much. I've made this trip many times before and usually consume the same amount going both directions. Wind was blowing, but not a whole lot. Maybe 5 to 10 mph, intermittently.
 
Adric, I'm interested in what you find out since our driving styles/distances are similar. Last month when the Leaf experienced the coldest temps (5-15 F), I had a situation where I lost THREE bars essentially sitting in the driveway (eventually one came back, but still it was weird). I had moved the car into the sun to see if I could warm it a bit more for a long drive. I charged up on L1 then was pre-heating for about 15 min before leaving. As for the GOM accuracy, it's really only suited for flat, in-town driving.
 
Reddy said:
Adric, I'm interested in what you find out since our driving styles/distances are similar. Last month when the Leaf experienced the coldest temps (5-15 F), I had a situation where I lost THREE bars essentially sitting in the driveway (eventually one came back, but still it was weird). I had moved the car into the sun to see if I could warm it a bit more for a long drive. I charged up on L1 then was pre-heating for about 15 min before leaving. As for the GOM accuracy, it's really only suited for flat, in-town driving.

OK, so I saw my Leaf hooked to a Leafspy yesterday. Sorry I don't have the screenshots (VRWL was supposed to email them, but I haven't seen them yet). But all of my cells were balanced. And the battery capacity was at 78% of original.

I have just a few months left on the lease and I keep wondering if I should buy it out. One thought that occurred to me: If I've lost 2 bars already at 30,000 miles. Then I'm bound to lose 2 more before 60,000 miles, which means Nissan will have to replace my battery. Which means sticking it out might be the best option for me, long term.
 
adric22 said:
I know there have been endless discussions on this forum about the GOM. But I've had my Leaf for over 3 years and 30,000 miles and this is the first time I've seen this.

and you still question it?

one thing; your first CP represents almost 3X the capacity of your 2nd CP but you already knew that.

2nd thing; driving the same course but in different directions?? I am willing to bet I know which way the wind was blowing.
 
I have what may be a similar problem, in that I can charge to 80% and get 10 bars or charge to 100% and see 12 bars, but about a week ago the GOM showed a big hit in driving range.
And my average miles/KWH dropped from 4.1 to 3.1

I'm in the Portland, Oregon area, so our temperatures are pretty moderate. The car is #847, I took delivery on April 9, 2011, and I'm just over 25K miles. I tried disconnecting the 12 volt battery for a few minutes, and checked the voltage during that time (12.56 V). Didn't help.

I don't have access to a GID meter or any other way to check the traction battery. Any suggestions will be appreciated.
 
jfsquires said:
about a week ago the GOM showed a big hit in driving range. And my average miles/KWH dropped from 4.1 to 3.1
A drop in m/kWh does not indicate a battery problem. In fact people with battery problems are more likely to see an increase in m/kWh as they try to compensate for reduced range. As I'm sure you know by now, m/kWh is sensitive to speed, speed changes in traffic, wind direction, and heater usage. If you have ruled those out, you might have low tire pressure or some friction such as a dragging brake pad. Or it could be the four bags of cement mix you put in the back a week ago. :lol:

Ray
 
jfsquires said:
I don't have access to a GID meter or any other way to check the traction battery. Any suggestions will be appreciated.
Get the LeafDD (search the forum) or Leaf Spy application (link to manual in my signature) so you can check your traction battery.
 
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