Six miles, Low Battery Warning to Turtle (Sans Effect)

[evnow]

I can see quite a few different opinions here. I guess we each have our own philosophy. But my philosophy is that I won't plan to take a trip in the Leaf unless I know I have a good 20+ extra driving miles. I would never plan a journey knowing that I would be flirting with turtle mode in order to make it there. ...
I would feel very embarrassed to have my Leaf towed away from the side of a highway. ...

20 miles!! That's 20-30% of the total range and WAY too much to just give away. Seems way to self-conscious an attitude for me. I'm not in Tony's league, but I don't mind hitting LBW close to getting home.

Actually 20 miles isn't oo much to give away. If we think after low battery we get 15 to 17 miles - we can look at 20 miles extra as planning to come home by the time Low Battery appaears. Doesn't sound unreasonable to me.

 

[Herm]

So, exactly what usage do you suggest I'm doing that is contrary to the terms of the warranty ?
Let me suggest, "none".

Oh I agree, since there is no warranty on capacity

But you are right, its unlikely the BMS will glitch at that precise moment, after it was probably not designed by Clarion or built by the lowest bidder. Dont mind me, I appreciate your experiments.

 

[Caracalover]

am curious as to what Model S he will be ordering (40 / 60 / 85 kWh?).

He can take the cheapest variant, and then rent the longer range models when he needs them, or so I have heard. The model S will have Nissan and others upping the offerings, after all, they can't say it can't be done if someone has done it. I would wager they are well aware of what they need to do, and market share and charging infrastructure seems to be the roads Nissan is pushing hard to own.

I do have to wonder if Tony will take the 300 mile version and not charge it until he has gone 305 miles though...

 

[Caracalover]

Incidentally, we just charged at the Air Quality Management District office in Diamond Bar ... We left our mountain home with seven bars of charge, and a cold battery (four bars), and arrived in Diamond Bar, where we spent the day, with two bars... the 60 mile drive home, with 5300' of net elevation gain. We pulled into the driveway with barely two bars of charge indicated, which dropped to one bar after power cycling the car. Drove 125 miles total with a 4.6 mile/kWh average. Everything worked out exactly as planned.

So am I right that on just 5 bars you went 60+ miles?

 

[abasile]

Incidentally, we just charged at the Air Quality Management District office in Diamond Bar ... We left our mountain home with seven bars of charge, and a cold battery (four bars), and arrived in Diamond Bar, where we spent the day, with two bars... the 60 mile drive home, with 5300' of net elevation gain. We pulled into the driveway with barely two bars of charge indicated, which dropped to one bar after power cycling the car. Drove 125 miles total with a 4.6 mile/kWh average. Everything worked out exactly as planned.

So am I right that on just 5 bars you went 60+ miles?

Yes, just over 60 miles with 5300' of net elevation loss. The first 16 miles involved descending our mountain, after which we had eight bars. (Regen was marginal due to the cold battery but we still picked up a bar.) After that, we used six bars to drive 44 miles, all on freeways at about 55 mph.

 

[HighDesertDriver]

Twice we have received the first low battery warning as the GOM passed 8 miles within a couple miles of home [...] On a recent cold night, however, we again got the LB caution about 1.5 miles of the house, but pulled into the garage on turtle with only four power bubbles.

If I read that right, you got LB warning with 8 miles on the GOM, but only were able to go 1.5 ? That's scary.

You are generally correct, but since I'm not sure how much further we might have been able to go, it would be best to say that we only went 1.5 miles (additional info: that distance involves a 150' climb) after LBW and arrived in turtle with four power bubbles. I was truly surprised, and after reading this thread I wish I had turned the car back on after a few minutes to see if the GOM changed. We don't have one of Gary's SOC meters, however, and in 20/20 hindsight, I doubt we would have been able to quantify any changes; i.e., "---" before shutting down, and "---" after powering back up.

I think it is good to know the limits of our machines, not to regularly operate at those edges, but to know what we might reasonably count on if circumstances someday demand. The colder weather has now introduced a new variable requiring a more conservative approach when poking into these unknown corners.

 

[LEAFfan]

Unless you happen to be driving in flat terrain, gauging charge remaining by "miles" is an exercise in futility.

There are many more variables than just flat terrain for range. The ambient temp makes the most difference other than a head or crosswind. When the outside temps are below 60, there is a big drop in your m/kW h due to the much denser air. The battery temps don't really vary that much. I've yet to see 4 bars or 8 bars. So far, it's 5 in the fall/winter and 6-7 in spring/summer. In the summer, I can easily beat the chart at suggested speeds, but it is much closer with the cooler temps.

 

[TonyWilliams]

I do have to wonder if Tony will take the 300 mile version and not charge it until he has gone 305 miles though...

Well, my LONGEST drive is 100 miles.... EXACTLY. Just what Nissan says it will do. Every other time I ran it out of "gas" was well short of 100 miles.

So, your analogy is a bit flippant. What I would do is drive a Tesla for 215.6 miles, and then run out of power, and then learn I got the usual smoke blown up my six o'clock. And then have Tesla apologists suggest I've done something improper on their internet forum.

 

[TonyWilliams]

It could be potentially dangerous if the BMS glitches at that point and allows a cell to be reverse charged below 0V.. but I'm sure the warranty would cover the damage... until Nissan pulls Tony's battery report and sees his history :shock:

So, exactly what usage do you suggest I'm doing that is contrary to the terms of the warranty ?
Let me suggest, "none".

Oh I agree, since there is no warranty on capacity

But you are right, its unlikely the BMS will glitch at that precise moment, after it was probably not designed by Clarion or built by the lowest bidder. Dont mind me, I appreciate your experiments.

So, which is it? Nissan won't cover any battery damage if they see my history, or they don't cover capacity? We, of course, know the answer to the latter.

If the battery is truly going to be damaged from operating within it's limits, then that's a problem. We don't actually know if there's a problem, and going to the dealer for a battery check would get me nothing but a piece of paper with 5 stars and no information (except to Nissan for their studies).

But, if I've permanently lost 5% of my battery capacity at less than 15,000 miles, that's a problem. You can belly ache about how it's not.

 

[GaslessInSeattle]

On my 58.8 mile loop around lake washington I have been essentially isolating for increased wind drag with colder air and some for the effect of cold on the battery and so far I've seen very little difference, though prewarming from 80% does appear to warm the battery too. I've managed to maintain a MPkW remarkably close to late summer, 4.2 vs 4.6 with a drop from 70 degrees to 39, If I turn on CC it goes down to 3.3. I'm looking forward to some colder nights to see if this continues to hold true.

g

Unless you happen to be driving in flat terrain, gauging charge remaining by "miles" is an exercise in futility.

There are many more variables than just flat terrain for range. The ambient temp makes the most difference other than a head or crosswind. When the outside temps are below 60, there is a big drop in your m/kW h due to the much denser air. The battery temps don't really vary that much. I've yet to see 4 bars or 8 bars. So far, it's 5 in the fall/winter and 6-7 in spring/summer. In the summer, I can easily beat the chart at suggested speeds, but it is much closer with the cooler temps.

 

[GaslessInSeattle]

I suspect that if all the cells degrade at about the same rate, they aren't going to cover loss but if a few fall outside the curve, they will cover them under warranty. One of the Tesla folks around here told me to expect a good chunk of degradation to happen in the first year or so and then level off, for whatever that's worth.

It could be potentially dangerous if the BMS glitches at that point and allows a cell to be reverse charged below 0V.. but I'm sure the warranty would cover the damage... until Nissan pulls Tony's battery report and sees his history :shock:

So, exactly what usage do you suggest I'm doing that is contrary to the terms of the warranty ?
Let me suggest, "none".

Oh I agree, since there is no warranty on capacity

But you are right, its unlikely the BMS will glitch at that precise moment, after it was probably not designed by Clarion or built by the lowest bidder. Dont mind me, I appreciate your experiments.

So, which is it? Nissan won't cover any battery damage if they see my history, or they don't cover capacity? We, of course, know the answer to the latter.

If the battery is truly going to be damaged from operating within it's limits, then that's a problem. We don't actually know if there's a problem, and going to the dealer for a battery check would get me nothing but a piece of paper with 5 stars and no information (except to Nissan for their studies).

But, if I've permanently lost 5% of my battery capacity at less than 15,000 miles, that's a problem. You can belly ache about how it's not.

 

[TangoKilo]

Tony... You sound a little irritated at being one of the ones that has...


At least running outta juice isn't as costly as gearing up...

 

[Herm]

So, which is it? Nissan won't cover any battery damage if they see my history, or they don't cover capacity? We, of course, know the answer to the latter.

I think they wont cover any capacity degradation because they dont want to set any precedents.. but they will cover any damaged cells no matter what you do to the car.. then again they may cover battery degradation on these early cars just for the good publicity. A BMS glitch is still an equipment failure.

 

[TonyWilliams]

Tony... You sound a little irritated at being one of the ones that has...


At least running outta juice isn't as costly as gearing up...

What are you talking about? Running out of juice costs nothing; gear up costs the insurance deductible ;-)

 

[surfingslovak]

I suspect that if all the cells degrade at about the same rate, they aren't going to cover loss but if a few fall outside the curve, they will cover them under warranty. One of the Tesla folks around here told me to expect a good chunk of degradation to happen in the first year or so and then level off, for whatever that's worth.

These are all valid points, and given the amount and type of information we have received from Nissan, it's no wonder that everyone is looking for the first sign of battery degradation practically on a daily basis. Based on what I have seen elsewhere, I would like to assure you that the cells Nissan used in the Leaf will very likely perform well. Not only that, they will likely exceed your expectations, especially if you live in a temperate climate, and go by the initial estimate of 30% capacity loss in 10 years.

That being said, I saw somewhat diminished performance yesterday as well. Typically, I can get at least 15 miles between LBW and turtle, but I only managed to get 10 the other night. My commute is fairly short, and I usually don't explore the lower reaches of the SOC range if I don't have to.

 

[91040]

My question is what would happen if, before the car completely dies, you pulled over and shut it off for, say, 15 minutes, then turned it on and kept going. My hypothesis is that you would gain at least a few miles over driving it to the bitter end. Or, after it did die, and sit for 15 minutes, would you suddenly have a few miles?

The reason I suggest this is that several times, I've drained the lead-acid battery in my ICE car, by leaving a light on overnight, for example, so it wouldn't turn over. When you turn off the light and let the car sit for 10, 15, 20 minutes, you suddenly have enough charge to turn it over a couple of times. Also, with my electric lawn mower, which has two lead acid batteries, when it runs out (always with just a few more feet of lawn to cut ) I'll let it sit for 10 minutes, and presto, I've got a few more minutes of run time.

Both of these examples are with lead-acid batteries, so maybe Li-ion doesn't behave like this, but I think the effect is just due to the internal chemical reactions in the battery, and if you give the battery some time not under load, it seems to recover a bit of charge.

Has anybody tried this with their Leaf?

BTW, I'm picking mine up tomorrow in Rockville, MD

I drove my car once until it was dead. Had to leave it over an hour with the emergency flashers on. When I returned, the car still would not shift into drive. Don't expect any recovery!

 

[DaveEV]

My question is what would happen if, before the car completely dies, you pulled over and shut it off for, say, 15 minutes, then turned it on and kept going.

I drove my car once until it was dead. Had to leave it over an hour with the emergency flashers on. When I returned, the car still would not shift into drive. Don't expect any recovery!

You missed an important word there - and the previous discussion of the car going into turtle much sooner than normal....

If you drive it until it won't move, it is well known that it won't let you start it back up again.

 

[DaveinOlyWA]

now i have done two "degradation" tests weakly disguised as "Winter Range tests"

one hypermile challenge, one freeway test. in both tests, i calculated a usable battery capacity of 17½ KW based on odo reading and Miles/kw reading after going to "near" turtle mode.

temps were mid to low 30's dipping into the 20's here and there. i choose to do that because we normally dont have weather that cold around here. i plan to run the same tests again but with temps in low to mid 40's (which is common here) to see if i can access more pack. unfortunately, i did not try this last winter so dont have a baseline from last year (which is a bummer, since i wanted to not stress my pack which seemed like a good idea at the time...why didnt anyone here try to talk me out of that!!)

 

[LTLFTcomposite]

I did push it to the low battery warning last night. For the benefit of those like me whose best laid plans are never to have this happen, can those who have been to the abyss confirm the sequence of events...

1) Battery level is low warning, both dash display and audio alert, vehicle still performs as expected
2) "a few" miles later, Battery is very low warning (also dash display and audio? and does the car slow down at all at this point?)
3) soon after that, "turtle mode", more visual and audible warnings, max speed like 20mph, maybe you get another mile
4) Complete immobilization, but the lights and flashers (and anything else on the 12 volt system) still work at least until the 12v battery dies

Also I assume somewhere in this sequence climate control is shut off

If you do take it to the bitter end, can it still be revived by charging, or is dealer service intervention required at that point?

Has anyone rescued a dead leaf with a generator?

 

[Herm]

If you do take it to the bitter end, can it still be revived by charging, or is dealer service intervention required at that point?

Its the dealer then, and they swap in a new set of Duracell batteries..