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

[marlon]

This is just fantastic, thanks for all the stats and links above. It's going to take me a while to figure this out. I'm sure I'll be back with questions. Is there an English translation for some of those links?
In the meantime, for all of you, my experiences so far: When I got down to 2 bars, the gas pump started flashing, the RR said about 9 miles. Turning on the heat lowered it to about 7. Then, with the RR at about 5 without heat (4 with), I got the last bar flashing alternately with the gas pump. However, no turtle. That was as far as I went. So I assume the turtle will show up after I hit 0 on the RR and I'm down to 5% of charge. Low power would hit at 3% and then the car would truly go dead at the true 0.

Also, I'm trying to make a charging graph. After the above trip, I'm measuring charging time at 120 v level one against the charge with a kill a watt. Unfortunitly, it doesn't record data, so its limited to each time i go look at it. I'm trying to watch it every hour but I have to go to sleep so my data won't be complete. Anyone know where I can get a recording electric meter that will graph charge vs. time automatically? It should be an exponential.
More power to all of us. We'll figure this out. Why doesn't Mitsubishi just make this stuff available? It could only encourage interest and sales.

In any event, I'll post my data, the best I can get, after I charge.

 

[Don]

Marlon,

There's a wealth of information here about how the car works, specifics of recharging and energy consumption and so on. Most of what it sounds like you want to do has been done several times and the results posted here

Joe's detailed charge logs may be of interest to you
http://myimiev.com/forum/viewtopic.php?f=9&t=403&hilit=wall+to+wheels&start=0

Don

 

[MLucas]

Nice set of information, makes things a lot clearer.

 

[marlon]

Question for Blue Lighting concerning the graph of bars vs. charge. You were ambiguous about the car "going dead." In the graph, I assume the x intercept is the "true zero charge." (or is there additional reserve not shown?)
Does the car stop moving (as in that now famous youtube video) when the battery is down to the true zero charge? I assume the x intercept. Looks like somewhere around negative 2 bars on the graph. Or does it stop moving at some higher point to protect the battery?
On the high end, I assume the car prevents charging up to the 17th bar to protect the battery from overcharging. Please clarify and correct anything I said wrong.

Also, where would the turtle come in on the graph? Different people seem to have slightly different experiences. I got down to the last bar flashing with RR of 5 and no turtle. (I don't plan to do that again in the near future.)

 

[BlueLightning]

Question for Blue Lighting concerning the graph of bars vs. charge. You were ambiguous about the car "going dead." In the graph, I assume the x intercept is the "true zero charge."

The x represent the charge the computer will allow you to use, not the entire charge of the battery. x in other words is what you see, (partially), and what the computer will let you use.
The y represent the State of Charge of the entire battery. At y = 0% the battery would be dead, but the computer will not allow it.

The 16th barre is overloaded, may be to hide later on a lost of capacity, over charge is impossible, the end of charge is like a soft landing with a decreasing amperage.

Also, where would the turtle come in on the graph? Different people seem to have slightly different experiences. I got down to the last bar flashing with RR of 5 and no turtle. (I don't plan to do that again in the near future.)

Yes, Mitsubishi and Peugeot have a different approach and there is evolutions, by exemple it might be different for me next thursday, Peugeot call my car for an update of the software "for emergency", this will be done next thursday, and I am not enthusiastic about it because the result is, for some folks, a lost of range.

I am confident with the batteries and the software management, the only serious problem to avoid for me is to have the batteries at full charge a long time in hot weather. Temperature and time, at 100 % SOC is a slow but real killer. In other words in hot weather, no problem to fully charge the batteries, but use straight away the car to decrease the charge. If the car stay idle, the battery would be better below 80 % State of Charge.
Li batteries are losing capacity at a higher rate in the southern States of the US than in the Northen ones.

 

[marlon]

to Blue Lighting (and anyone else interested)

I think I've got it.
Does this sound right? The turtle should come on at about the right end of the zero bar on teh graph when the RR shows --. The power down stage probably hits about the middle of the zero bar and the car goes dead at the left side of the zero bar on the graph when there is still about 8% charge in the battery.
Also, when I got down to the last bar, it was flashing along with the fuel pump. Does this fit with your experience?

 

[BlueLightning]

For y = 5% State of Charge, for iOn (Peugeot car) the car goes "dead" but the battery is still alive with 5% of electricity load.

The number for i-miev might be 8% SOC for the car to be "dead"

I will make the graph clearer when I will have time

 

[leec]

5.2 miles is my maximum run with the turtle light lit. I was able to climb some steep grades towards the end which I was sure would kill power to the car, but getting a run on level ground kept the amps low enough to avoid a shutdown. The AeroVironment meter indicated 1% as reported by the car when it was plugged in.

 

[marlon]

Thanks for the input on the turtle light.
Do you remember when it came on? When I had the last bar flashing, there was still no turtle light. Was there a reduction in power? You said you kept the amps down. Was that intentional or forced?
Also, I don't have an AeroViornmental charger (I use standard plug) so I'm not familiar with it other than its 240v. It sounds like it tells you the state of charge of the battery. Do you know if that's a true 1% or if the car is still hiding the 8% reserve it doesn't let us use (as per blue lightning)?

Marlon

 

[JoeS]

leec, congratulations on your long-distance trip and thank you for posting that AeroVironment photo. I didn't realize that there was any data fed back to the EVSE back through the J1772 connector. Wow, a whole new subject to explore...

Back on topic, all this micro-analysis as to what really happens when the car goes turtle is fine from an academic perspective, but perhaps a reminder that this happens in a battery region that none of us should ever be venturing into. Under normal circumstances, there's no excuse for going there. It's sort of like asking how far and for how long can you keep an internal combustion engine above its red line (before they had rev limiters). Thankfully, the iMiEV BMS is there for protection.

 

[Don]

leec, congratulations on your long-distance trip and thank you for posting that AeroVironment photo. I didn't realize that there was any data fed back to the EVSE back through the J1772 connector.

I didn't either. From what I understand of the J1772 standard, there's no path for such information exchange. If you know something we don't leec, please enlighten us as to the electrical path for such info

Back on topic, all this micro-analysis as to what really happens when the car goes turtle is fine from an academic perspective, but perhaps a reminder that this happens in a battery region that none of us should ever be venturing into. Under normal circumstances, there's no excuse for going there.

I agree. In 6500 miles of driving the car, we got back home one time with 4 miles RR showing on the clock . . . . and we got busy recalculating exactly where we went wrong to ensure that never happens again, and it hasn't

Don

 

[marlon]

Dear All:

Yes, I agree. No one should get the turtle. I never have and don't plan to. However, yes, it is an interesting academic point. After all, anyone who drives an i miev has to have some interest in batteries and how the charge works. That's part of the fun. In any event, I've been reading about batteries and the best way to preserve them. Now, I know why different people say different things. It's apparently somewhat controversal. Some say you need to cycle the battery a few times to get the full capacity but others say not with Li ion.
I'm always interested in any new input.
On a related topic (I probably should post this elsewhere), it looks like turning on the heat drops the RR between 1/3 and 1/4. That seems to actually approximate what I read on this forum from John Annen that 40 min of heat takes one bar. Occassionally even more than a third. I still love the car and this isn't a problem for me, but no one ever told me it could be so dramatic. Maybe that's one reason they aren't selling well.
It'll be interesting when it gets warm and I hit the air conditioning.

 

[Don]

We drove all summer in temps of 85 to 95 degrees using the A/C. It's not the big 'range killer' that the heater is in our experience - A/C usage usually reduced our range by about 10 to 15%. The EPA rated the car's range at 62 miles and we get every bit of that and usually a little more driving with the A/C on. Staying off the freeways and keeping speeds at 45 or less, we typically got 70 to 75 miles

If the car does what you need it to do using the heater this winter, you'll be pleasantly surprised with your experiences next summer, IMO

Don

 

[fjpod]

Hit turtle mode today. Nt on purpose mind you. But I ran for about two miles, mostly downhill thankfully. I did not notice a big loss of power, but I tend to drive in Eco mode. The heater/defroster is a big charge killer. Much more than I expected.

A tip when you are low on charge...and you need the defogger....leave the temp on green and just use a little fan, and oh, stop breathing. It will work.

Using the heat may force me into getting a 220 volt EVSE. I hope my 80 mile range comes back in the spring.

 

[leec]

leec, congratulations on your long-distance trip and thank you for posting that AeroVironment photo. I didn't realize that there was any data fed back to the EVSE back through the J1772 connector. Wow, a whole new subject to explore...

This was reported via a CHAdeMO station, which certainly does read the battery voltage and communicate with the car to prevent overheating during DC fast charging. Sorry if that wasn't clear from my post.

Back on topic, all this micro-analysis as to what really happens when the car goes turtle is fine from an academic perspective, but perhaps a reminder that this happens in a battery region that none of us should ever be venturing into. Under normal circumstances, there's no excuse for going there. It's sort of like asking how far and for how long can you keep an internal combustion engine above its red line (before they had rev limiters). Thankfully, the iMiEV BMS is there for protection.

That's an interesting comparison, running an ICE above redline puts mechanical stress on components beyond their design thresholds. Operating a battery vehicle below it's safe voltage thresholds isn't as likely to cause a catastrophic failure, given that the BMS can prevent a cell reversal and keep the pack balanced. Certainly one should minimize the time spent at low voltage and avoid operating there at all if possible, but I think you're mischaracterizing the risks.

 

[JoeS]

Certainly one should minimize the time spent at low voltage and avoid operating there at all if possible, but I think you're mischaracterizing the risks.

Lee, you're right that I'm perhaps being a bit overly conservative. The modern BMS protecting the batteries is perhaps analogous to the electronic rev limiter keeping the engine just at the red line. Within the design limits, but perhaps don't want to dwell there.

 

[leec]

Hit turtle mode today. Nt on purpose mind you. But I ran for about two miles, mostly downhill thankfully. I did not notice a big loss of power, but I tend to drive in Eco mode. The heater/defroster is a big charge killer. Much more than I expected.

A tip when you are low on charge...and you need the defogger....leave the temp on green and just use a little fan, and oh, stop breathing. It will work.

Using the heat may force me into getting a 220 volt EVSE. I hope my 80 mile range comes back in the spring.

Another means of extending range in cold weather is preheating the car and even stopping to run the heater while plugged in. Even the 110 volt adapter will produce enough energy to run the heater although it will impact recharging at the same time.

 

[Don]

Hit turtle mode today. Nt on purpose mind you. But I ran for about two miles, mostly downhill thankfully. I did not notice a big loss of power, but I tend to drive in Eco mode. The heater/defroster is a big charge killer. Much more than I expected.

Yup - Compared to an ICE, it's just the opposite. Heat is plentiful and basically 'free' in an ICE car since most of the gas you buy goes up into the air as wasted heat, but it's sure nice to have that unlimited heat in the winter time . . . . the ICE pays a bigger penalty when you try to cool the car . . . . that generates even more heat

Using the heat may force me into getting a 220 volt EVSE. I hope my 80 mile range comes back in the spring.

If you're still using the OEM trickle charger, maybe just a 12 amp upgrade would be all you'll need? Just doing that will cut your recharge time by 1/3rd

Pretty sure you'll see your 80 mile range again next spring/summer. Oddly, when we bought the car, we were worried about the actual range we would have during the summer months. As it turns out, summers are no problem . . . . the shortest ranges we've seen have all been in the past couple weeks

Don

 

[fjpod]

Hit turtle mode today. Nt on purpose mind you. But I ran for about two miles, mostly downhill thankfully. I did not notice a big loss of power, but I tend to drive in Eco mode. The heater/defroster is a big charge killer. Much more than I expected.

Yup - Compared to an ICE, it's just the opposite. Heat is plentiful and basically 'free' in an ICE car since most of the gas you buy goes up into the air as wasted heat, but it's sure nice to have that unlimited heat in the winter time . . . . the ICE pays a bigger penalty when you try to cool the car . . . . that generates even more heat

Using the heat may force me into getting a 220 volt EVSE. I hope my 80 mile range comes back in the spring.

If you're still using the OEM trickle charger, maybe just a 12 amp upgrade would be all you'll need? Just doing that will cut your recharge time by 1/3rd

Pretty sure you'll see your 80 mile range again next spring/summer. Oddly, when we bought the car, we were worried about the actual range we would have during the summer months. As it turns out, summers are no problem . . . . the shortest ranges we've seen have all been in the past couple weeks

Don

I plan to do both eventually. Too cheap to pay nearly $1000 for an EVSE, which is not even a charger. (LOL...but I bought the car for 29 times that). Yup, I think the AC is much gentler on the batteries than the heater.

 

[marlon]

Dear All:

Haven't been on the site in a while. Not much action on this discussion lately, I see. Thought I would report an interesting finding. My dealer is 30 miles away. Took the car for the recall work on the brakes (anyone have any thoughts on this?). They told me they had a Level 3 charger. When I was there I found out they don't. (I can't find anyone with one, seems like I have a useless option.) I managed to get a boost for 30 minutes on the 220 charger. I left with RR showing 38. I drove 45 in echo mode, no heat, but I think I was going into the wind. Well, it wasn't that close. I made it with RR showing 2 and zero bars. Apparently, the last bar flashes and then goes out. However, the RR wasn't at zero. And, no turtle. I guess he would come up after the zero. Here's my big question. I charged the car and put in 17kwh. I think my kill-a-watt is accurate. It always seems to give me numbers that approximate everyone else. Is that possible? By the way, after charging, the RR read 84, my best ever, so I must have been pretty careful.

Marlon