Battery died, 1st time experience.

[garygid]

Just ONE cell-pair, not charged as much as the 95 other pairs, can bring about a "sudden" (unexpected) lack of power at the low end of the SOC range.

Unless you find a way to watch the voltage of the lowest cell-pair (instead of the Pack's voltage), "surprise" endings will remain un-anticipated. Thus, to avoid towing, Nissan apparently wants to encourage you to STAY AWAY from the UNCERTAIN "reserves" at the low end.

CAUTION: Since (I believe) the low-end SOC readings CAN easily BE misleading, there is NOT a dependable reserve, always available to use.

What we need is an SOC properly based on the lowest cell-pair.

Even with "apparent" remaining-SOC being reported, the car CAN "unexpextedly" slow and quit moving, leaving us (just sometimes) with VERY LITTLE dependable RANGE after the Low Battery Warning.

The question is, "Do you feel Lucky today?" ...

 

[TonyWilliams]

What we need is an SOC properly based on the lowest cell-pair.

Gary,

Why have you not invented this yet? Don't make me come up there with my Fluke!!!

 

[smkettner]

I prefer to focus on staying out of the low battery warnings and turtle mode rather than engineering a method to know if I have 2.23 miles or 0.621 miles left. No matter what the measure, at some point the car will stop. Additional information will not allow the car to proceed any further. If the tow truck picks you up five miles from home or one half mile does it matter?

BTW I love to hear these stories of just making it.... or not

 

[dznit]

It's summer, & it's HOT!

Has anyone correlated the: outside Temp & Battery Temp along with the Range?

Could it be that the Battery Temp could effect the range & account for some of
the variable Range data?

 

[leafme]

The remaining usable power at the low end of the battery
appears to be somewhat unpredictable at this point.
Likely, I think, that this is the reason for the "hidden" reserve.

Use Caution.

This is VERY troubling. This is the second time that I know of that this has happened. We absolutely need this to happen with an SOC meter hooked up to see what the heck is going on!!

Data Event #----A-----B-----C-----D----E-----F-----G---This Event
LowBattery----11.0---8.6---13.6---6.7---16---10---9.9----9.7
VeryLow-------6.7----5.5---8.4---5.2---10----7----8.0---0.5

Total2Turtle-17.7---14.1--22.0--11.9---26---17---17.9--10.2

VeryLow/Low--61%---64%----62%---77%----63%--70%--80%----5%

C = Me at about 38-45mph with lots of rolling downhill
E = Edmonds 132 mile run at 35mph on a track

Tony,

If I get this data right, worst case, I can expect 10.2 mi after I hit low battery before I get to turtle. Is this correct?

tx

Malcolm

 

[derkraut]

"Tony,

If I get this data right, worst case, I can expect 10.2 mi after I hit low battery before I get to turtle. Is this correct?

tx

Malcolm "

Depends on how fast you drive, uphill or downhill, or level ground, outside temperature, if you're using heat/AC. In other words, it will still be just a guess.

 

[Herm]

You cant avoid turtle range variability, it depends on each cell having the same exact capacity since the pack is top balanced (as should be)... if you want to extend turtle just slow down as much as you can, down to a walking pace if conditions allow.

 

[TonyWilliams]

I prefer to focus on staying out of the low battery warnings and turtle mode rather than engineering a method to know if I have 2.23 miles or 0.621 miles left. No matter what the measure, at some point the car will stop.

The amount of distance is a bit more than 2.23 miles, and yes, the car will stop when it runs out of power. But, some of us prefer to know WHEN that is, and not be left to guessing. I fully understand that there are those who do not.

Staying out of the Low Battery Warning is sage advice, but that also leaves a significant portion of the usable range of the car not used. For a car that might go 80-ish miles total, the 12-15-ish miles that remain at LBW are significant. Particularly for those of us, like myself, that have up to 140 mile days.

Additional information will not allow the car to proceed any further. If the tow truck picks you up five miles from home or one half mile does it matter?

Some of us actually make it home after LBW and even Very Low Battery. Data is good. No tow truck needed. I hope you never need one, either.

 

[TonyWilliams]

"Tony, If I get this data right, worst case, I can expect 10.2 mi after I hit low battery before I get to turtle. Is this correct?
Malcolm "

Depends on how fast you drive, uphill or downhill, or level ground, outside temperature, if you're using heat/AC. In other words, it will still be just a guess.

Data Event #----A-----B-----C-----D----E-----F-----G---This Event
LowBattery----11.0---8.6---13.6---6.7---16---10---9.9----9.7
VeryLow-------6.7----5.5---8.4---5.2---10----7----8.0---0.5

Total2Turtle-17.7---14.1--22.0--11.9---26---17---17.9--10.2

VeryLow/Low--61%---64%----62%---77%----63%--70%--80%----5%

C = Me at about 38-45mph with lots of rolling downhill
E = Edmonds 132 mile run at 35mph on a track

Malcolm,

The data that I presented above are not guesses, but ACTUAL data of events. Is 10.2 the worse case that I'm aware of ? Yes.

As derkraut aptly points out, it could be worse!! But, if you are driving to your significant life event, and Low Battery pops up, and you have 10.1 miles to go, do you:

A. Drive 5 or more miles out of your way to a charger that may or may not be available (and if not working/available, you absolutely will not make your life event)?

B. Slow down to something below 60mph and go for it, knowing that 12-16 miles is likely based on many other documented experiences?

C. Pull off the road, call a tow truck, and write an Edmonds article (ok, that one is already taken)?

For me, having the experience of six turtle events and the confidence in the shared data of others like me, I'd absolutely choose B, and have done so many times.

But, let's say you had that same 10.1 to go to your life event, and you know that there is a charger along your route at about the time you expect to hit Very Low Battery. Absolutely, hedge your bets. Stop and get that L2 charge, for 5 minutes for every mile remaining in your trip.

Worry about how you'll get home later !!!

Let me add a somewhat related thought. Today, I drove to Balboa Park, 20 miles from my house. I've begun accumulating data to generate data to adjust our mileage estimates for elevation/grade changes (which is the second biggest impact to range after speed).

I got on the freeway at 60mph on cruise control, and immediately reset the miles/kWh data on the dash. Then put the GPS data on the Navigation screen for altitude information. About 600 feet.

I drove the 20 miles until about 100 feet elevation in downtown San Diego. The difference of about 500 feet of those 20 miles. Difficult to judge that loss of elevation without actually looking. I did coast (in neutral) a few of the hills, and ended up with over 5.0 miles/kWh.

I knew I wouldn't get that going home, but I was surprised that is was 3.8.

My point; the almost unnoticed environment has a significant impact on your range. Now, add in the fact that the very bottom of these batteries has left a few folks significantly short of the expected range, well, like many things in life, you bet on the PROBABLE and accept the POSSIBLE.

Hope this helps.

Tony

 

[jason98]

What? I've never heard of anyone getting turtle at the same time as VLB. I see from the delivery chart that you got your car in early March. It sounds to me as if you have never gotten the firmware upgrade. True?

Ray

I had the upgrade. And yes, turtle happened immediately after the "very low" warning.

 

[LEAFfan]

Hmm, I didn't realize you were doing that. When you charge to 80%, is the 10th bar full or 30% full? If it was partially charged, then the 17kWh would make sense. Otherwise, it should be 18kWh.

Every time after charging to 10 bars (83% SOC), the first bar (3rd) always disappears after just a few miles so I know it isn't nearly full. Sometimes after charging to 83% SOC, I lose the first bar (3rd) before leaving the garage.

 

[Stunt822]

ran out of juice experimenting too. after long trip arrived home with dashes, and was able to get another 7 miles at 20-30mph around neighbourhood. after turtle kicked in I berely made 1/2 mile, and rolled to my driveway, but not on to it. My L2 can't reach that far!!! Took around 2 hours on L1 with extention cord to get car to get in gear so I can reach L2 charger.

with couple of trickle charges and 90% of charge in the morning - make 120 miles total with AC, but can't calculate exect numbers due to unknown charage from trickles.

 

[surfingslovak]

Every time after charging to 10 bars (83% SOC), the first bar (3rd) always disappears after just a few miles so I know it isn't nearly full. Sometimes after charging to 83% SOC, I lose the first bar (3rd) before leaving the garage.

Hmm, interesting, thank you for that data. I think that settles it then, 80% charge most likely corresponds to 17kWh of available capacity.

 

[jason98]

Average efficiency: 5.2 mpkwh
Total distance: 85.2 miles
Effective 80% capacity: ~16.4 kwh
Effective 100% capacity (x 1.25): ~20.5 kwh
Freeway miles: 15 (top speed 59 mph)
Express ways miles: 60 (top speed 50 mph)
Almost no AC
Low battery level warning: 75 miles (4 miles remaining)
Very low battery level warning and turtle mode: 84.7 miles
Turtle distance: 0.5 miles

I had a chance to reach the turtle mode driving around neighborhood.
So I have a kind of update almost a year after my previous experience of fully used battery.
After the "Limited engine power" message I had to drive only a quarter of a mile to my house, so no service was needed.

So this time:

Average efficiency: 5.6 mpkwh
Total distance: 90.0 miles
Effective 80% capacity: ~16.1 kwh
Effective 100% capacity (x 1.25): ~20.1 kwh

Compared to a year and 12000 miles ago, my battery capacity reduced from 20.5 to 20.1 which indicates about 2% degradation.
Note that I charge to 80% every night, except rare weekends (once a month in average) when we plan longer trips within Leaf's reach.