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

[jray3]

I'll accept PV1's defense this time, but my wife certainly has a much better lifetime efficiency average in MR BEAN. Unless circumstances are extenuating, I usually drive it like I stole it.

Sandange, my recalibration recharge was on L2 in freezing temperatures. I have't studied it, but have not noticed any long-lasting effect of recalibration, probably because we do it so often. This morning when I left home with the heater blasting, RR was 45, just like normal.

MR BEAN gets two deep L1 recharges per week during my wife's overnight shifts, and usually gets down to two bars or less for a recalibration recharge on L2 at least once per week. The main change in our usage pattern is that I now use DCFC pretty rarely. Due to the unreliability and cost of DCFC, I'm down to maybe one session per month rather than at least one per week, which was the rule from 2012-2015. We did this by having my wife keep the car on what used to be a double-electric commute day, but the net effect is only shifting about 15-20 more miles per week to our gasser.

 

[Don]

She was hypermiling pretty well . . . . :lol:

Don

Maybe, but the distance driven by Jay should've mostly overwritten the previous drive (16.4 miles total - 1.5 mile tow = 14.9 miles driven by Jay).

True, but the last 15 miles only serves to show you how far you can then go based on what's left - When you recharge and get 85 miles RR, that's based on how you drove for the entire charge used, not just the last 15 miles

Carolyn does really well when driving the car too, though I don't think she really tries hard . . . . she just has a light foot

Don

 

[barrylevine]

I just drove about the last 5 miles of a 61 mile trip with the turtle lit up (and was very glad to pull into my driveway.) My first instance of turtle riding. But I don't understand why this happened. I've driven this same route a few times previously with about 12 miles range remaining. It's a non-highway route done mostly at 35-45 mph. The car was fully charged (done overnight the previous day, then sat unused for 1 day). I wasn't using the heater. It's a 2016 iMiev, with less than 4k miles.

The only thing I can think is that I hadn't run the SOC gauge down to below 2 bars for a while. Is it possible to get a false empty reading due to lack of gauge recalibration? False turtle?

 

[JoeS]

The only thing I can think is that I hadn't run the SOC gauge down to below 2 bars for a while. Is it possible to get a false empty reading due to lack of gauge recalibration? False turtle?

Barrylevine, your trip could be classified as a bit of a nailbiter and glad you made it home without having to push the car. To answer your question, I don't think it' a gauge calibration issue, but perhaps others have some ideas...

How about some external factors:

1. Ambient temperature (even though you did not run the heater)
2. Headwind (this is often a sleeper)
3. Not paying attention during the first part of the trip and then very belatedly realizing that perhaps a bit of hypermiling was needed to get home
4. Rain or snow
5. Tire pressure

When you started your trip, do you remember your RR?
After your return, recharging gave you what RR?

In any case, if you fully fully recharged after that turtle experience then your system probably recalibrated itself. Always fun to check things with EVBatMon (capacity) and CaniOn (cell balance) when you're at extremes.

Good luck, and let us know how you do on this same trip in the future.

BTW, whereabouts are you located?
http://myimiev.com/forum/viewtopic.php?f=13&t=3196

 

[barrylevine]

Thanks for the feedback.
I'm located in a suburb of Boston.
When I started the trip, my RR was about 54 miles. Usually it's 70 or even 80 something after recharging, if I've been on non-highway roads, which is typical.
So I thought that was a little low, but thought maybe it reflected a recent stint on a highway. The SOC was full.
We've had some temperatures in the 20's - 30's (F). That's not really THAT cold.

I did have the windshield defroster set on the bottom dash dial, although no A/C or heat was selected, and no fan. That never seemed to much of a range depleter.

I was a little heavy footed on the way out on this trip, I'll admit.

Once I got home and recharged, RR was 58. That seemed pretty low after such a sedate drive home. Usually after this trip, the recharged RR is in the low 80's.

I may have to look into the diagnostic equipment (Canion), or see if the dealer can check the battery. The car is only 6 months old.

The only thing I can think is that I hadn't run the SOC gauge down to below 2 bars for a while. Is it possible to get a false empty reading due to lack of gauge recalibration? False turtle?

Barrylevine, your trip could be classified as a bit of a nailbiter and glad you made it home without having to push the car. To answer your question, I don't think it' a gauge calibration issue, but perhaps others have some ideas...

How about some external factors:

1. Ambient temperature (even though you did not run the heater)
2. Headwind (this is often a sleeper)
3. Not paying attention during the first part of the trip and then very belatedly realizing that perhaps a bit of hypermiling was needed to get home
4. Rain or snow
5. Tire pressure

When you started your trip, do you remember your RR?
After your return, recharging gave you what RR?

In any case, if you fully fully recharged after that turtle experience then your system probably recalibrated itself. Always fun to check things with EVBatMon (capacity) and CaniOn (cell balance) when you're at extremes.

Good luck, and let us know how you do on this same trip in the future.

BTW, whereabouts are you located?
http://myimiev.com/forum/viewtopic.php?f=13&t=3196

 

[kiev]

32F = 0C which is considered very low by the batteries

 

[JoeS]

...I did have the windshield defroster set on the bottom dash dial, although no A/C or heat was selected, and no fan. That never seemed to much of a range depleter....

Hmm, that setting automatically turns on A/C (the light comes on) and I can't help wonder if the heater is not simultaneously engaged (despite the top knob being horizontal) - there's a discussion of this somewhere on this forum. A few weeks ago I engaged that rare (for me) setting and was surprised to see both the fuel gauge and RR drop quickly.

 

[Don]

On my cars, it doesn't turn on the A/C *if* the fan is set to OFF like he said his was

Don

 

[JoeS]

On my cars, it doesn't turn on the A/C *if* the fan is set to OFF like he said his was

Good point, and I failed to take that into account. I invariably have the fan going and the external air flowing through. Will check it when I get home (I'm still in OZ and saw my second EV, a Tesla).

 

[barrylevine]

The only thing I can think is that I hadn't run the SOC gauge down to below 2 bars for a while. Is it possible to get a false empty reading due to lack of gauge recalibration? False turtle?

Barrylevine, your trip could be classified as a bit of a nailbiter and glad you made it home without having to push the car. To answer your question, I don't think it' a gauge calibration issue, but perhaps others have some ideas...

How about some external factors:

1. Ambient temperature (even though you did not run the heater)
2. Headwind (this is often a sleeper)
3. Not paying attention during the first part of the trip and then very belatedly realizing that perhaps a bit of hypermiling was needed to get home
4. Rain or snow
5. Tire pressure

It's looking like ambient temperature does take a nice bite out of the range, irrespective of other sources of battery drain.

During summer and spring, RR after various non-highway 40-60 mile runs followed by overnight recharge (always at 12A, 120V) was 80-90 mi.
During 20-30F weather I started getting RR values after recharge around 60.
Since my first post on this topic I did a non-highway run of about 40 miles (with a starting RR in the 60's) during a warm spell around 50F.
Overnight recharge ran the RR back to 87. (sigh of relief, battery is OK).
Next day colder (about 30 F) , did a run of about 40 miles easy-going on back roads. Charged overnight, during which the temperature dropped into the 20's. And the RR = 64 in the morning.

 

[JoeS]

barrylevine, thanks for the feedback. I wouldn't read too much into the RR reading, as it is sooo dependent on the conditions under which/how the last 15 miles were driven. I wager that no one on this forum can predict exactly what their own exact full-charge RR number will be. :roll:

 

[jray3]

The return of 50 degree mornings near Seattle is starting to affect my morning RR readings, which have stayed above 62 this summer despite over 90k miles on the odometer. Well, I pushed my limits once last week and confirmed that I'm down to about 2 miles left in the turtle, with 33.2 Ah reported capacity. This is the second time ever that MR BEAN has been driven to the point of shutdown (1.5 miles short of home). The battery resting voltage was 306.5V at 40 degrees C (104 F), and a wide disparity of 0.63 Volts between the highest and lowest cell surfaced. Cell #8 was 3.70V and cell #19 was 3.07V. State of charge in this condition was reported at 4%. Contributing factors were leaving home with a partial charge and being only a week into a new set of tires (Continentals up front and Don's $45 specials out back), with tire pressures still down low at the installer's 32 psi.
After a full recharge and overnight balancing, the high and low cells were within a coupla hundredths of a volt, RR was 54 miles, and then I aired 'em up to 42 psi.

I'm noticing after some testing that the displayed penalty for heater use is growing proportionately higher, with the RR settling down at 34 after a minute of full heat. I presume the software is applying a fixed heat load to the smaller battery capacity, yielding a proportionately larger range impact (37%).

I was hoping to push this battery to 100,000 miles of service (there's always hope for a sick cell to win a warrantied pack replacement), but after I get a few other round tuits cleared away, the time may come to replace this battery with the low mileage junkyard spare I picked up early this year. Then the original pack could be used as a range trailer or the cells parted out for use in a conversion and i-MiEV spares for other high-mileage pack rebuilds as they fall out of warranty.

As I drove the hobby cars more during the dry season, MR BEAN's annual mileage rate fell from 19k to 17k, but the return of rainy weather will crank that back up, and with any luck (and judicious heater use), MR BEAN will achieve 100k miles by the end of February.

I've updated my entry on the i-MiEV mileage spreadsheet and encourage others to do the same.
https://docs.google.com/spreadsheets/d/1OeAzxJnJbTmGhS2hcnjazD7-60J4AXtlJdPeCQ8R2Zc/edit#gid=0
-Jay