Turtle riding (How far has the turtle brought you ?)

OK, completely unintentionally, I hit turtle last week. Had to make a trip that was approximately 75 miles in total(accumulation of miles, a few legs worth), and actually stopped at a Walgreens drugstore as a precaution. My Range inidicator showed 7 miles left, I had about 14 miles to travel, so after 45 minutes of charging I assumed I was safe. No, I miscalculated. Drove the last 2 miles with a flashing turtle. Car never slowed down, never noticed any reduction in motor capacity. In any event, I am going to be a little more careful next time I take a longer trip. I think that I misjudged how many miles a Level 2 charge would give me, I had figured about 17 miles per hour, I forget now what my range indicator said after charging but I thought I'd have an extra mile or so. Oh well, next time I'll sit for a full hour or more and I'll have no worries. Interesting that I then charged to 100% and the car was at 77 miles range the next day. That's the most range I have seen indicated, likely that the battery was depleted and I think I have read here that doing that occasionally can reset the battery cycle?

Lou

Lou, good for you for a lesson learned relatively painlessly and inexpensively. Your RR=77 is very good and reflects your conservative driving (at least for the last 15 miles). Your recharge rate depends on whether the L2 charging station is operating off 208vac (one leg of a three-phase system) or 240vac. Typically, I estimate an average of 12miles/recharge hour at 240vac based on my own overall wall-to-wheels energy consumption of 4.2miles/KWhr. When taking longer excursions with the iMiEV we try to plan around stopping for meals near a charging station or visiting friends and plugging in … so-called "opportunity charging".

Dear Joe:

(See my last post above). I got about 30 minutes on the dealer charger. They didn't seem to know much about their own charger. Couldn't tell me how much charge or just what type of charger it was. However, the RR went from 27 to 38. Interestingly, I only went from 7 to 8 bars. I would think 11 miles should be worth 2 bars. I also used up 36 miles on the RR going home even though its only a 30 mile trip but the car must have thought I did a good job because when I fully charged up the RR read 84 miles, thats my best. I think there's a lot of guess work here or unknown variables. Also, I never heard of a flashing turtle. Does the turtle always flash or is that some additional warning?

Joe:

Asa you said, lesson learned. At home I only use Level 1, but I suspect that some charging stations are better than others(ie:faster, even using 240V, there seem to be differences).

Lou

marion, I've never taken my fuel gauge nor RR down to zero (and plan on never going there!), so can't tell you what turtle does. From your earlier post where you measured 17kWh input energy into a fully-discharged battery - this is ok, because you need to account for the charger power conversion efficiency which I would guess to be around 90% at 120vac (it's slightly more efficient at 240vac). The fact that you got up to RR=84 after you fully charged is a testament to your efficient driving. My own rule of thumb is that at 120vac the fuel gauge goes up four bars for every five hours of charging and at 240vac it goes up around three bars/chargehour. RR recovery/depletion is very much dependent on how you were driving. If I'm in the mood to test myself as to how efficiently I'm driving, the game I play is to reset the GPS tripmeter (it's a stand-alone cheap Garmin) and then see if I can get my mileage driven + RR reading to be greater than the RR number I started with.

Thanks for the response. So if I'm losing 10% of my charge the imiev is more efficient than we give it credit for. On the other hand, the wall to wheels number is still the same. I haven't heard this mentioned before. Concerning my boost at the dealer, it may have been charging longer than they said. I agree with you on the charge times. The only thing I still can't explain is why the RR added 11 miles with only one bar. That would get me over a 160 miles on a full charge which certainly makes no sense. Perhaps it really went from .6 to 1.4 bars and the rounding gave me only 1. Even then, it seems a little high at 5 miles per bar.
Off topic, anyone else get hit with this brake system vacuum pump and "clipper charger" recall.

Marlon

marlon said:

The only thing I still can't explain is why the RR added 11 miles with only one bar. That would get me over a 160 miles on a full charge which certainly makes no sense

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The RR bases all of it's computations on what you've been doing for the last 15 miles. I'm guessing you were driving very efficiently on your way to the dealers - Probably 30 or 35 mph stop and go? You used very little juice in that 15 miles, so when you add some juice, it 'credits' you with range like you were getting during the last 15 miles

If you had driven those 15 miles to the dealers at 70 down the freeway, you would have been using more than twice the juice in THAT 15 miles, so when you recharged that same amount at the dealers, it would have only 'credited' you with 4 or 5 miles on the RR dial

If you leave home fully charged and drive very carefully at 30 or 35 mph, you CAN go 11 miles on the first bar on the fuel gauge - I keep an eye on mine often to see how far I can make it before it takes away that first bar . . . . 11 or 12 miles is about average if you're being really careful

Also - The fuel gauge doesn't interpolate very well - The one bar you saw may well have been actually 1.45 bars . . . . not enough to show 2, but still way more than 1

Joe measured the very small, actual amp draw at a steady 22 miles an hour and computed the theoretical maximum range and it was an incredible number - Something over 250 miles! Refresh my memory, Joe - How far was it?

Don

Don't forget on round trips like to the store and back. It may be downhill to the store, and maybe you used 10 miles of RR, but coming back it might be uphill and you might use 20 RR. When you got to the store, you thought you only needed 10 to get back, but you really need 20. Careful.

It's just a hunch, but I feel the last quarter of the pack goes faster than the first.

Don said:

Joe measured the very small, actual amp draw at a steady 22 miles an hour and computed the theoretical maximum range and it was an incredible number - Something over 250 miles! Refresh my memory, Joe - How far was it?

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Well, that was a theoretical number of 533 miles on a single charge, but that was only if one considered energy used for propulsion and ignored all other vehicle energy consumers (which are significant). Here's the link: http://myimiev.com/forum/viewtopic.php?p=2857#p2857

The key point is that if you're running on 'empty', then SLOW WAY DOWN (like 20-25mph), don't accelerate or decelerate, be sure all loads are off (heating, aircon, headlights if possible, etc.), and you will be able to dramatically extend the distance you travel.

Just got my meter this week and found out 1 bar is almost exactly 1 kilowatt hour charging. I have got the 16 kWh battery.

Then calculated a bit, 1 kilowatt hour (charged) gets me some 7.5 kilometers or 4.66 miles. That should give me a total of 120 kilometers or 75 miles. The turtle wants 2 bars or 15 kilometers to visit her friends so I should rather expect 105 kilometers or 65 miles. I have actually driven some 111 kilometers once with the turtle giving me a fit.

Depending on where I come home from, I see some 72 to 164 kilometers of range after fully charging, centering about 110 to 120 recently.

Weather has changed here. It is still below zero at night but can reach some 10 Celsius during daylight. (below 32F up to 50F) I hope when temperature is up to 30C (86F) again I see 145 kilometers or 90 miles again. I am quite sure our Lithium Cobalt batteries behave better with high temperatures than Nissan's Lithium Manganese do.

Seeing amperes going down with the final two bars, charging more often but not up to the rim can reduce time. Charging earlier than reaching the bottom keeps the turtle from waking up and can reduce stomach aches.

Remember, remember, 16 bars is a virtual gauge, what the turtle wants us to see. So you can actually charge 16 kWh out of the mains but that does not mean you have put 16 kWh into the battery nor does it mean you can put 16 kWh out of the battery into the motor. It is still nice to play with 16 bars/kWhs as if that was the real thing.

Update -- the other side of the hill and driving home with full heater:

29.7 kilometers, 6.987 kWh that is 4.2 kilometers or 2.6 miles in a bad winter night. It should give me 68 kilometers or 42 miles. Global warming has hit us again. Spring is over. The Ice Ages are back :shock:

Today was an interesting one. My wife, daughter, and I took my wife's ICE to our friend's house for a party. I was driving and noticed the temperature gauge rising... rising... oh crap! Thankfully, I noticed it before the engine had any permanent damage. I limped it back home (including some coasting with the engine off!) and we got in the i-MiEV.

Now you have to understand: Our friends live 35 miles away, and their house is only accessible by expressway. I considered this in the past and knew this would be nearly impossible on one charge. Oh, and it's mostly uphill. I kept the speed down to the speed limit (you have to understand -- in Texas, speed limits are merely a guideline :lol and drafted a large semi truck most of the way at around 60MPH.

We arrived with 7/16 bars available. For once, I displayed the guess-o-meter. It read 32 miles left. That's cutting it too close. Being the nice friends they are, they allowed me to L1 charge at their house using the stock EVSE (8A @ 120VAC). We were there for around 3 hours. The guess-o-meter showed 35 miles, but I knew that was understated. That was just enough to get us home with 3 bars left.

After dropping the wife and kid off, I ran an errand and used a lot of battery going fast. Got it down to 2 bars, just like the manual says to do occasionally. This is the first time I've ever driven so far in my car and the first time I've seen 2 bars.

I'll post what my kill-a-watt meter shows for my power usage later.

After you fully charge, your RR will tell the world just how efficiently you'd been driving the last 15 miles or so...

As you saw, there was no reason not to take the iMiEV on a 35-mile (one-way) trip, even with L1 opportunity charging. If you had done the EVSEUpgrade (or had a portable L2 EVSE), with a simple adapter you could have plugged into your friends' dryer outlet and been fully charged before setting off for home. Saves getting ICE anxiety.

Agreed. I just ordered one of the Clipper Creek L2 EVSEs on their March Madness deal, and I plan to put a standard 240V plug on the end for use as a portable EVSE as I need it.

Unfortunately, I cannot report my power consumption numbers as my car was still charging this morning! I saw 10.74kWh on my kill-a-watt meter after being plugged in around 8pm. That left me three bars short of a full charge. :evil:

Fjpod,
For the first time in this forum, I see someone reporting on what I have observed, too. That is, the last quarter of the charge gives less range. When I was on my mission to drive some 90 miles to visit a friend, I had a passenger recording everything. It turnes out, that the sum of miles driven plus RR increases as we used up first half of the battery, actually reflecting extremely efficient driving style as the last 15 miles for RR calculation at the beginning are not the same as RR after hypermiling. Conversely, the last four bars, no matter how hard I tried, slipped on this figure.

My hypothesis is that the calculation of RR uses 330V fixed voltage while the battery voltage actually decreases as the SOC lowers.
This effect is rather very small and difficult to notice. However, if you typically drive with over 8 bars and need to strech your trip down to the last bar, you may get into unpleasant surprise that those last bars are worth less range. The good thing is that the turtle provides good compensation for it as you can continue driving in turtle mode for maybe 5 miles with no bar (?) - don't take it for granted. At any rate, depleting battery that low is not good for it.

jaracz, I like your hypothesis and will try to post some of my own logging, but my gut is in full support!

I recently had my first encounter with the turtle.

My girlfriend and I took a 66 mile round trip with a two more passengers in the back. We were going from Salt Lake City to a small town in Utah called Tooele.

There wasn't really a route I could take that had no freeway driving, but I picked the road that I could drive a bit slower on (and that was a couple miles more direct). I put the car in eco to curb my over-eager acceleration, and tried to drive between 45 and 60 the whole time. (After driving 65-70 on the freeway to work and back most days, my RR is usually between 62 and 66, so I thought I'd be in good shape. Granted, there were three more people in the car so that might have weighed me down.)

One thing the i-MiEV made clear is that there's at least a slight incline on the way there. There weren't a lot of real steep hills, but the incline that was there definitely sucked some energy. By the time we arrived, I'd lost two bars past the halfway point. I knew I'd get some help coming back, but with the range estimate giving me 10 miles less than I needed, I was pretty worried.

After an initial failure to find a place to charge, I went back outside and found a wall outlet to plug into for an hour of 110v/12a charging, which still didn't get me back to the halfway point or to a 33 miles range estimate. I went up from 24 to 27.

Luckily, the incline made a huge difference. After getting over a couple small hills, I was able to drive the first 10 miles coasting or just poking into the green, and my RR was at 28 when I got to the freeway entrance 10 miles later. The rest of the drive was less consistently downhill, however, and I still ended up seeing the turtle with 2 or 3 miles to go. I made it home before it went to slow down mode or anything, but it was still a little worrying.

It all worked out OK, but after this experience, I'm not sure I'd attempt going more than 60 miles round trip without assured access to L2 charging or a few hours at L1.

nsps said:

I recently had my first encounter with the turtle.

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Your story reminds us of how we need more charging stations.
If Tooele had a DC Fast Charge station, say at the local shopping center, you could have made a quick 15 minute stop and had plenty of charge to make a convenient round trip.
When I have to make a longer trip I also map it out and am disappointed when I can't take my i-MiEV simply because there are no charging stations.
I feel that a network of DC Fast Charge stations will lead to greater acceptability of electric vehicles.
The sales pitch for DC Fast Charge stations is "50 miles range in 15 minutes." Who doesn't have 15 minutes?

RobertC said:

Who doesn't have 15 minutes?

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Do you work for Geico? :lol:
(Apologies to US visitors for the joke; apologies to non-US visitors for not understanding the reference.)

jaraczs said:

Fjpod,
For the first time in this forum, I see someone reporting on what I have observed, too. That is, the last quarter of the charge gives less range. The good thing is that the turtle provides good compensation for it as you can continue driving in turtle mode for maybe 5 miles with no bar (?) - don't take it for granted. At any rate, depleting battery that low is not good for it.

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Maybe the turtle is why the last few bars disappear so quickly, which would then beg the question, why weren't the rest of the bars shifted so all are equal? I noticed this with my car, too. Quite a cold chill when you're 8 miles out and suddenly go from 4 to 2 bars over 3 miles. Although I have noticed 3 miles RR with no bars and no turtle.

RobertC said:

nsps said:

I recently had my first encounter with the turtle.

Click to expand...

Your story reminds us of how we need more charging stations.
If Tooele had a DC Fast Charge station, say at the local shopping center, you could have made a quick 15 minute stop and had plenty of charge to make a convenient round trip.
When I have to make a longer trip I also map it out and am disappointed when I can't take my i-MiEV simply because there are no charging stations.
I feel that a network of DC Fast Charge stations will lead to greater acceptability of electric vehicles.
The sales pitch for DC Fast Charge stations is "50 miles range in 15 minutes." Who doesn't have 15 minutes?

Click to expand...

Definitely. Even if the Walgreens there had an L2 charger, I could have taken my folding bike, dropped my passengers off, dropped the car there and rode my bike to meet them. Unfortunately there were zero charging options of any kind, and I only lucked out that there was an empty parking space by the 110v power outlet at the hotel next door.