Vike
Posts: 400
Joined: Sun Jun 10, 2012 8:25 pm
Location: Albuquerque, New Mexico

Re: Battery temperature management

Sat Aug 03, 2013 10:50 pm

Well, when it comes to the i-MiEV's lack of active air cooling, I've decided to:

- Stop picking on LEAFs and their missing battery cooling systems; we're in the same boat

- Do more of my driving with A/C off and the windows open; better for the battery and I prefer it anyway (but of course I'll continue to use A/C whenever that's more comfortable)

- Order in a set of wind deflectors; I like the way they look and they'll let me crack a window for air while still keeping the sun off

- Stop worrying about it; won't help, probably not a problem anyway
2012 Silver ES w/QuickCharge+DRL/foglights, Eaton Level 2 EVSE, since 9/9/2012

siai47
Posts: 360
Joined: Fri Jun 14, 2013 5:54 pm

Re: Battery temperature management

Sun Aug 04, 2013 4:10 am

Vike, I noticed you have QC in your ES. You could easily cool your battery with the A/C system if you wanted to.

I found an interesting post from High-Tech Industry in Japan that's over a year old talking about a successor to our batteries which is called the LEV50N. One of the items mentioned is "The new product has higher durability in a hot environment----" It appears that these went into production after our cars were built and might be found in the new PHEV offerings. Link:

http://hightechindustryinjapan.blogspot ... m-ion.html

JoeS
Site Moderator
Posts: 3574
Joined: Thu Dec 15, 2011 5:47 am
Location: Los Altos Hills, California

Re: Battery temperature management

Sun Aug 04, 2013 9:05 am

siai47, thank you for this link. Ooooh, batteries with high-temperature tolerance AND lower cost - maybe that's Mitsubishi's secret weapon for the future? :o
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

aarond12
Posts: 388
Joined: Fri Jan 25, 2013 2:21 pm
Location: Dallas, TX

Re: Battery temperature management

Mon Aug 12, 2013 8:48 am

I'm opening this can of worms again, because of yesterday's drive. I have an ES without CHAdeMO.

Yesterday, we had a typically hot Dallas day. I was on the freeway around 70-75 MPH with the air conditioning on. The temperature gauge showed 104°F (40°C).

When I pulled into the house, we had a lot of things to unload from the car. I left the car "running", but turned off the A/C. The fan in the front of the car, which typically shuts off immediately when I turn off the A/C, stayed on for another 5 minutes or so. Inside the car, I could faintly smell the odor of antifreeze (coolant).

Are we *certain* the ES doesn't use the A/C to cool the battery?
2015 Nissan LEAF S

siai47
Posts: 360
Joined: Fri Jun 14, 2013 5:54 pm

Re: Battery temperature management

Mon Aug 12, 2013 9:38 am

The electronics are liquid cooled in this order---Charger---inverter---motor. What you heard is the radiator/condenser fan running to cool off the antifreeze circulating in the coolant loop. It will run for a while to get the system cooled down. There is no battery cooling while driving regardless of what options you have on your I-MiEV. If you are smelling coolant, check the level of coolant in the bottle on the left side of the motor compartment (under the lid) and make sure it is up to the "full" level. If I was driving in temperatures like you are seeing, I would put a fan under the car in the garage to blow air underneath it to cool the battery some by convection.

aarond12
Posts: 388
Joined: Fri Jan 25, 2013 2:21 pm
Location: Dallas, TX

Re: Battery temperature management

Mon Aug 12, 2013 2:07 pm

siai47 wrote: If you are smelling coolant... I would put a fan under the car in the garage to blow air underneath it to cool the battery some by convection.

I'll check the coolant level when I get home. This was the worst conditions I've driven the car in before (heat-wise), so I wasn't too surprised to smell coolant. I have a fan to exhaust the hot air from the garage, so it doesn't get way too hot in there. Maybe I'll put my box fan in front of the car after a hot drive like this weekend's. I rarely take the i-MiEV on the freeway even on cooler days, so this shouldn't be an issue in the future either.

Edit: The coolant level is at exactly "full" on the reservoir. I guess it's possible the coolant expanded enough to go into some overflow (possibly dumped on the road?!) for me to be able to smell it.
Last edited by aarond12 on Tue Aug 13, 2013 7:29 am, edited 1 time in total.
2015 Nissan LEAF S

RobertC
Posts: 292
Joined: Fri Jul 27, 2012 7:35 am
Location: Winter Garden, FL

Re: Battery temperature management

Mon Aug 12, 2013 3:54 pm

I charged my i-MiEV yesterday at a Blink DC Fast Charger from 40% to 80%.
The air conditioner ran to cool the battery starting at 40%, but stopped running at 68.5%.
The battery pack temperature went from 28.6 degrees C (83.4F) to 31.6 degrees C (88.9F). The outside temperature was 75F.

Battery temperature at 40%. (Using CaniOn)
Image

Battery temperature at 79% (Blink Charger said 80%)
Image

Amps History showing the DC Fast Charge.
Image
The total charge time was 13 minutes.
The total gain in range according to the range remaining meter was 38 miles.
The i-MiEV charged at over 40kW for the first couple minutes, after which the charger ramped down.
”Blue” - 2018 Kinetic Blue Chevy Bolt Premier with QC - 5/13/18
“Red” - 2017 Cajun Red Chevy Bolt LT with QC - 3/30/2018
"Purple" - 2012 Raspberry Metallic ES with QC - 4/10/2013

fjpod
Posts: 529
Joined: Tue Apr 17, 2012 2:31 am
Location: NYC

Re: Battery temperature management

Mon Aug 12, 2013 5:13 pm

If I am reading this right, battery temp does not rise much even under DC quick charge?

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

Re: Battery temperature management

Tue Aug 13, 2013 12:48 pm

From what I have learned (mostly evtv.me and Lithium Iron Phosphate) charging with 0.1 C (10 hours), 1 C (1 hour) or even 10 C (6 minutes) a charge to 80% does not raise cell temperature very much but a charge above 90% even at 0.1 C or less does dramatically. That is why some people think charging above the point where constant current is changed for constant voltage does reduce cell life and quickcharging is actually better for the cells.

Another curious discovery was the algorithm that was meant to charge to 80% actually charged 90%.

They have got new cells with another technology and are experimenting with these too.

You put in some 7 or 8 kilowatt hours and temperature climbed some 3 celsius. Ok climate control helped a bit but that still looks very promising.

Thanks for sharing.
Peter and Karin
Peter and Karin Dambier, DL2FBA, www.piraten-fraktion-bergstrasse.de

RobertC
Posts: 292
Joined: Fri Jul 27, 2012 7:35 am
Location: Winter Garden, FL

Re: Battery temperature management

Sat Dec 28, 2013 3:45 pm

I charged today at a Greenlots DC fast charger in Mount Laurel, New Jersey (the second fast charger to open in New Jersey) located about 40 miles from my house. The traction battery was about 40 degrees F when I started charging, and the DC fast charger only charged in the 40 to 50 amp range for the first six minutes of the charge.
Image

Heres a closer look. After about six minutes the battery started to charge at about 77 amps before ramping down as usual.
Image

Previously while DC fast charging, the battery would immediately charge at between 110 and 120 amps as soon as I plugged in. I'm not sure why this time was different? I couldn't find any documentation that shows the i-MiEV DC fast charges slower at 40 degrees F.

Also, it looks like the i-MiEV always stops DC fast charging at 80% state-of-charge. You have to restart the DC fast charger to charge more than 80%.
”Blue” - 2018 Kinetic Blue Chevy Bolt Premier with QC - 5/13/18
“Red” - 2017 Cajun Red Chevy Bolt LT with QC - 3/30/2018
"Purple" - 2012 Raspberry Metallic ES with QC - 4/10/2013

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