garygid
Posts: 187
Joined: Fri Oct 05, 2012 10:19 am
Location: Laguna Hills, CA 92653
Contact: Website

Re: Traction Battery/Cell Voltages

Wed Jan 30, 2013 7:28 am

Please keep us posted about what you find for
DC to DC conversion.

Depending upon when you intend to "feed" the Traction
Battery Pack, you might find that you need a lot more than
just 10 amps (about 3.5 kW) to be useful while driving.

Cheers, Gary
LEAF owner, EV supporter

JoeS
Site Moderator
Posts: 3759
Joined: Thu Dec 15, 2011 5:47 am
Location: Silicon Valley, California

Re: Traction Battery/Cell Voltages

Wed Jan 30, 2013 8:21 am

garygid wrote:Please keep us posted about what you find for DC to DC conversion. Depending upon when you intend to "feed" the Traction
Battery Pack, you might find that you need a lot more than just 10 amps (about 3.5 kW) to be useful while driving.

Gary, I agree with you if I were only roaring down the highway; however, this auxiliary pack is merely meant to supplement the iMiEV's traction pack. Using normal hypermiling techniques, and being off-highway for at least some of the time, 10A steady-state should be more than enough to feed the traction pack and extend the iMiEV's range by, say, 15 miles if I were to use a 4kWh pack. I'd probably start off smaller (in both amperage and pack capacity) just to prove the concept.

Haven't found any 48vdc --> 340v dc-dc converters off-the-shelf yet, although I have a possible lead on a custom design.
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

peterdambier
Posts: 284
Joined: Thu Oct 04, 2012 3:26 am
Location: Bergstrasse, Germany

Re: Traction Battery/Cell Voltages

Wed Jan 30, 2013 11:26 am

Could be easier than you think:

230V arith is 330V eff. So an inverter that delivers 230V AC, a bridge rectifier and a capacitor will get you there. Most likely an UPS for PC backup power will do the job.

http://en.wikipedia.org/wiki/Diode_bridge

For the more daring an inverter for 120V and a voltage doubler will do as well.

http://en.wikipedia.org/wiki/Voltage_doubler

Figure 4. Bridge (Delon) voltage doubler is my favorite.

It is not so important to aim for a certain voltage and 5 decimals. The sine wave of the inverter and the inertia of the 16 kWh battery pack will get you there. As long as you feed outside the battery managements' realm the BMU knows what goes in and out of the batteries. As long as you feed only as long as the power gauge stays below 80% you cannot do harm to the batteries.
Peter and Karin Dambier, DL2FBA, www.piraten-fraktion-bergstrasse.de

JoeS
Site Moderator
Posts: 3759
Joined: Thu Dec 15, 2011 5:47 am
Location: Silicon Valley, California

Re: Traction Battery/Cell Voltages

Wed Jan 30, 2013 12:39 pm

Peter, thanks for your input and I understand what you're saying (shades of my past life). I will certainly try your approach for a quick-and-dirty experiment using one of my other EVs, and then I will see if I need to have control over the output voltage and current if I'm to use it in the iMiEV. I need to get a 48vdc-->240vac inverter anyway in order to be able to feed my L2 EVSE and "conventionally" charge my iMiEV in an emergency (I have about 50 12v AGM and Gel batteries around here I could use if needbe). Certainly less input current draw than a 12v --> 240vac inverter.
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

jray3
Posts: 1657
Joined: Tue Dec 06, 2011 1:05 am
Location: Tacoma area, WA
Contact: Website

Re: Traction Battery/Cell Voltages

Tue Feb 26, 2013 3:01 pm

y'all may be interested in Ben Nelson's testing of a single cell that was submerged in salt water for 3 1/2 months, yet still delivers decent amp-hrs!
http://300mpg.org/2013/02/25/40-amp-tes ... hium-cell/
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

Don
Site Moderator
Posts: 2879
Joined: Thu May 10, 2012 3:55 pm
Location: Biloxi MS

Re: Traction Battery/Cell Voltages

Tue Feb 26, 2013 5:35 pm

Everything he does is interesting to me, and it's really cool that the guy who bought this car is so dedicated to documenting everything. We're all going to learn LOTS about our cars!

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

JoeS
Site Moderator
Posts: 3759
Joined: Thu Dec 15, 2011 5:47 am
Location: Silicon Valley, California

Re: Traction Battery/Cell Voltages

Tue Feb 26, 2013 7:04 pm

Before we lose it again, the Mitsubishi target full-charge cell voltage is 3.955v
(Ref: http://myimiev.com/forum/viewtopic.php?p=7380#p7380)

At full charge for the 88 cells, this yields 348.040volts.
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

BlueLightning
Posts: 53
Joined: Sun Oct 14, 2012 11:59 am
Location: Normandy France
Contact: Website

Re: Traction Battery/Cell Voltages

Wed Mar 27, 2013 1:56 pm

I am sorry I did send a wrong information in a former message viewtopic.php?p=8480#p8480 saying i-miev battery might be a Lithium iron phosphate battery

Here is the Material Safety Data Sheet of the LEV50 50Ah 3.7V Lithium Ion Cell,
http://www.ens.dk/da-DK/KlimaOgCO2/Tran ... gbiler.pdf

Cathode :Lithium-Manganese Dioxide (activity)
Polyvinyldiene Fluoride (binder)
Graphite (conductivity)
Anode :Carbon (activity)
Polyvinyldiene Fluoride (binder)
Electrolyte :Organic Solvent (non aqueous liquid)
Lithium Salt
Others :Heavy metals such as Mercury. Lead, and Chromium are not used in the cell.

"The LEV50 cell going into the i MiEV pack is a 50 Ah, 3.7V cell using a mixed LMO/NMC cathode material with a hard carbon anode. The combination offers a specific energy of 109 Wh kg-1, and energy density of 218 Wh L-1."
http://www.greencarcongress.com/2009/06 ... 90612.html

The Battery Pack for Mitsubishi’s i MiEV
http://www.greencarcongress.com/2008/05 ... ts/page/2/
Mitsubishi and GS Yuasa developed the cell for both high specific energy and high rate discharge. The newly developed prismatic cell used in the i MiEV pack has a specific energy of 109 Wh/kg and specific power of 550 W/kg. Energy density is 218 Wh/L. The entire pack has a specific energy of 80 Wh/kg.

The cell—and pack—feature high capacity retention at constant current discharges. Capacity at the high current of 200A is slightly less than at the lower rates (93.9% of capacity).
When discharged with an ambient temperature of 25° C, the pack is capable of delivering the maximum power from 80% DOD. Even at 0°C, the pack can deliver the maximum power from 70% DOD and enough power for propulsion from 90% DOD.
http://bioage.typepad.com/.shared/image ... imiev2.png
http://bioage.typepad.com/.shared/image ... imiev3.png
http://bioage.typepad.com/.shared/image ... imiev1.png

Image

DonDakin
Posts: 387
Joined: Wed Aug 15, 2012 7:10 pm
Location: Montreal Quebec.....

Re: Traction Battery/Cell Voltages

Sat Apr 06, 2013 12:14 pm

Hello guys,

I remember a thread about reading the iMiev can bus data into an android phone via a can bus->bluetooth adapter. Is this already done ? I was thinking it would be nice to get some data out of the car and look at the individual cell data to get a feel for the general battery health and how it's progressing. The people at Mitsubishi don't really seem to know much about this car so I would to get the info right from the car.

Anyone out there know what is already existing for getting the data and analyzing it ?

Anyone have a dongle that works on the imiev ?

Can I hook up a simple cable to the rs-232 port on a laptop and gather data simply ?

Thanks in advance

Don.....

Barbagris
Posts: 237
Joined: Wed Feb 20, 2013 8:34 am
Location: Bilbao, Spain

Re: Traction Battery/Cell Voltages

Sat Apr 06, 2013 1:17 pm

DonDakin wrote:Hello guys,

I remember a thread about reading the iMiev can bus data into an android phone via a can bus->bluetooth adapter. Is this already done ? I was thinking it would be nice to get some data out of the car and look at the individual cell data to get a feel for the general battery health and how it's progressing. The people at Mitsubishi don't really seem to know much about this car so I would to get the info right from the car.

Anyone out there know what is already existing for getting the data and analyzing it ?

Anyone have a dongle that works on the imiev ?

Can I hook up a simple cable to the rs-232 port on a laptop and gather data simply ?

Thanks in advance

Don.....


Yes. This thread:

Android CAN Monitoring App

Examples:

Image

Image
...learning...

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