kiev
Posts: 930
Joined: Sun May 03, 2015 7:15 am
Location: The Heart o' Dixie
Contact: Website

Re: Power consumption for balancing the battery ??

Sun Jan 22, 2017 9:51 am

Found some info on the German site that Martin updates the Canion app.

a charging power curve showing the length of taper/balancing phase
Image

Some discussion about the missing power:

When I load [aka charge], so messe z.b. 220V and 14.2A, gives 3.1kW. On Canion are displayed 356V and 6.7A, makes 2.4kW.
Where are now the 0.7kW difference?

1. The charger in the i-MiEV has an efficiency of 90%. Of the 3.1kW remain 2.8kW (-0.3kW) remain.

2. The i-MiEV has a standstill (ignition on, without charging cable) of 1.1A or 0.4kW for the operation of all control units and the charging current for the 12V battery. Control units and charging the 12V battery (300 ~ 360V -> 14V converter) remain in operation when charging the 360V battery.

Of the remaining 2.8kW (point 1) thus still another 0.4kW away. This leaves 2.4kW.
kiev = kenny's innovative electric vehicle

JoeS
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Re: Power consumption for balancing the battery ??

Sun Jan 22, 2017 6:02 pm

First, addressing meier's original query -
meier wrote:...I had a short drive aprox 20km / 12,5m and wanted to charge to test what kw i had used for that tour - the result was depressing ... because of the balancing process...
Yes, the variability due to balancing (and other factors such as temperature) over a short drive won't really tell you much. For myself, I kept meticulous records for 8000 miles and came up with an average of my own consumption for my i-MiEV but then gave up any more datataking because I realized that external influences (such as running the heater) have a ridiculously-high impact on the numbers.
Ref: http://myimiev.com/forum/viewtopic.php?f=28&t=403&start=20#p5744

meier, I was mulling over your question and kiev's response is probably as good as you're going to get.

If it's of any help, I dug up an old TED graph from 2012 so you can see what the power draw looks like when the charging starts tapering off and does its cell balancing. The voltage shown (red line) must be doubled (TED was only looking at one leg of the split-phase 240vac line). The drop in the curve soon after charging starts is the usual 'timeout' that the charger does, which I speculate is to determine if there is an abnormal sag in the battery's voltage and is a safety feature built into some chargers.

Image

Regarding charging to 100%, car manufacturers are very careful with their wording, as Nissan found out when they were penalized when they were forced to post the car's range at 80% SOC rather than 100% because they were recommending that for everyday normal use people should charge to 80%. As another visual datapoint, here's a photo of the latest Tesla screen I took today (note that I am 'storing' the car and keep it at 50%SoC until I need it next). Tesla provides a simple programming option of stopping charging anywhere between 50% and 100% (I have yet to charge mine to 100%, but perhaps should do so one of these days to ensure the cells are balanced).

Image

I won't get into this off-topic debate other than say that I support Don's comments. On the Tesla Motor Club website there are many well-informed in-depth discussions on this subject, which has been beaten to death on just about every EV forum out there. For my own i-MiEVs, I rarely charge over 13 bars (and immediately drive the car if I do), almost never go below two bars, and hope that my battery pack rewards me with a long life for treating it this way. I'll never know if there will be a difference compared to simply having charged it to 100% every time. Anecdotally, there have been at least two battery replacements on this forum after people repeatedly charged to 100% in a hot climate.
EVs: 2 Wht/Blu SE Prem., '13 Tesla MS85, 3 156v CorbinSparrows (2 Li-ion), 24v EcoScoot(LiFePO4)
EV Conv: 156v '86 Ram PU, 144v '65 Saab 96
Hybrids: 48v1kW bike
ICE: '88 Isuzu Trooper. Mothballed: '67 Saab (orig.owner), '76 MBZ L206D RHD RV

Don
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Re: Power consumption for balancing the battery ??

Mon Jan 23, 2017 11:52 am

JoeS wrote: Tesla provides a simple programming option of stopping charging anywhere between 50% and 100% (I have yet to charge mine to 100%, but perhaps should do so one of these days to ensure the cells are balanced)
That's a feature I really, really wish we had on the iMiEV. I would use it every day

For those who don't recall, Joe took a 10,000 mile trip around the USA in his Tesla yet he's still never fully recharged to 100%

Don
2012 iMiEV SE Premium, White
2012 iMiEV SE, White
2017 Chevy Volt Premier
2014 Ford Transit Connect XLT SWB wagon, 14,000 miles
1979 Honda CBX six into six

blackheart
Posts: 142
Joined: Sun Mar 13, 2016 9:41 am
Location: Portland Or

Re: Power consumption for balancing the battery ??

Mon Jan 23, 2017 1:27 pm

Don wrote:
JoeS wrote: For those who don't recall, Joe took a 10,000 mile trip around the USA in his Tesla yet he's still never fully recharged to 100%

Don


If I had the range to spare on a daily driver, then I wouldn't charge to 100% either. However, during the winter months, I have used as much as 85-90% of my 36 mile round trip commute. I don't have the ability to plug in at work so I pre-heat in the morning, drive gingerly to work - about 20-25 min, and use about 4-5 bars - so that is 12 bars left.
Sometimes, on my trip home, traffic is so bad that I am sitting in the car for over an hour - with the heater on, even as minimal as possible. And the return route is mainly uphill, so there have been times when I have gotten home with only 2 bars showing.
During the summer months, I usually have between 7-9 bars remaining when I get home.
But I always charge to 100% over night b/c I never know when I am going to need to make an extra trip, run an errand, etc. Remembering my reading when Mitsu was asked why they developed a car with such a small battery, the response from Mitsu was that the car would be recharged every night at home. There was no need for a larger battery. I can't find the quote now, but that is what I remember reading.

And with their 8 year/100,000 mile warranty - my hope is that the Mitsu engineers planned on the battery going to 100% every night.
I understand folks squeezing the most life out of their battery, and wanting to stay in that sweet spot. However, with my commute, especially during the winter months, that would prove to be a very short range car and not very usable.
(my 2 cents)
'Is treading water actually swimming - or just prolonged drowning"

-2012 MItsubishi I-Miev - BlackJack
-1989 GMC Sierra 4x4
-2015 RadRover Emonster bike


EVSEupgrade

jray3
Posts: 1629
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Location: Tacoma area, WA
Contact: Website

Re: Power consumption for balancing the battery ??

Mon Jan 23, 2017 1:35 pm

I'll offer MR BEAN as the extreme example- he's being run for maximum economic utilization. The car sat unused for a year after manufacture (likely at a high SOC) and has been charged to 100% just about every night since, with 100% midday charges about 3x per week, plus many CHAdeMO sessions. My recent 6 miles on the turtle 'till involuntary shutdown shows that the battery degradation has been minimal after 65,000 hard miles.

-Jay
2012 i-SE "MR BEAN" 105,400 miles
2000 Mazda Miata EV, 78 kW, 17 kWh
1983 Grumman Kurbwatt EV,170 kW, 32 kWh
1983 Mazda RX-7 EV 43 kW 10 kWh
1971 "Karmann Eclectric" EV 240 kW 19 kWh
1965 Karmann Ghia Cabriolet

Lic
Posts: 65
Joined: Mon Dec 28, 2015 2:11 pm
Location: Canada

Re: Power consumption for balancing the battery ??

Mon Jan 23, 2017 8:38 pm

kiev wrote:
Of the remaining 2.8kW (point 1) thus still another 0.4kW away. This leaves 2.4kW.

So if you use regular mitsu L1 charger you are getting only 0.4kW charging rate. Not much.

meier
Posts: 36
Joined: Tue Aug 16, 2016 5:30 am
Location: Denmark / EU

Re: Power consumption for balancing the battery ??

Thu Jan 26, 2017 6:10 pm

Thanks alot for this comprehensive reply - Im not sure i understand the graph though - it seems that there is a very little period around 1 minute only in the end with balancing I have experienced i gues more than 1 hour i think - - BUT i will monitor it and make some testing when i have the time :-)
c-zero - 2011 - 35000km

JoeS
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Re: Power consumption for balancing the battery ??

Fri Jan 27, 2017 12:26 pm

meier wrote:Thanks alot for this comprehensive reply - Im not sure i understand the graph though - it seems that there is a very little period around 1 minute only in the end with balancing I have experienced i gues more than 1 hour i think - - BUT i will monitor it and make some testing when i have the time :-)
meier, we are on the same page. If you'll look at the abscissa of the graph it is time using a 24-hour clock in one-hour intervals; thus, the balancing point starts at around 21:20 and continues for at least an hour. BTW, you had included a repeat of my entire post which I took out to keep things simple.
EVs: 2 Wht/Blu SE Prem., '13 Tesla MS85, 3 156v CorbinSparrows (2 Li-ion), 24v EcoScoot(LiFePO4)
EV Conv: 156v '86 Ram PU, 144v '65 Saab 96
Hybrids: 48v1kW bike
ICE: '88 Isuzu Trooper. Mothballed: '67 Saab (orig.owner), '76 MBZ L206D RHD RV

meier
Posts: 36
Joined: Tue Aug 16, 2016 5:30 am
Location: Denmark / EU

Re: Power consumption for balancing the battery ??

Fri Jan 27, 2017 2:15 pm

JoeS wrote:meier, we are on the same page. If you'll look at the abscissa of the graph it is time using a 24-hour clock in one-hour intervals; thus, the balancing point starts at around 21:20 and continues for at least an hour. BTW, you had included a repeat of my entire post which I took out to keep things simple.



Ahhh of course i must have been tired - yes I see its almost an hour :-)
c-zero - 2011 - 35000km

thomash85715
Posts: 37
Joined: Sat Apr 01, 2017 9:05 am
Contact: Website Facebook

Re: Power consumption for balancing the battery ??

Sat Apr 01, 2017 12:04 pm

Hello: I just joined because I am inching closer to purchase of a 2012 i-MiEV with 17K miles on it. I would like to know exactly how many kWh it will use to go from no charge to full charge on the included 120VAC small charger. I have a Kill-A-Watt device that will show accumulated draw over a specified time; has anyone use one of those to determine this? I am assuming the car would pull more current at the beginning then taper off toward the end of the charging period; just trying to quantify that. I realize the charge time is long for this included device but I cannot afford to add fast 240VAC charger to my house right now.
Also, exactly how is the battery warranty transferred to a subsequent owner? Is there a transfer fee or registration procedure or does mitsubishi track it via VIN? THank you from Tom in Tucson AZ.
In an insane society a sane man would appear insane.
Acquired 2012 silver ES April 2017.

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