Battery air intake

I'm planning to purchase a 2011 Citroën C-Zero, the Citroën's variant of i-MiEV. I live in Finland, northern Europe, where the winters can get a litte harsh. Harsh as in -25 Celsius (-13F) is not uncommon at all. It can stay around those temperatures for days.

As lithium batteries don't particularly like to be charged when frozen I'd like to heat the pack while charging and/or before driving to maximize the range and minimize battery degradation. Also the iMiEV may not start charging if the pack is too cold.

So the question is, where is the air intake of the iMiEV battery pack located? Looking at Ben's iMiEV videos it's apparent that the is a round intake near the emergency plug, or just in front of it, pointing toward the front of the car. Is this hole easily accessible from inside the car, perhaps right in the driver footwell?

What I'd do is buy one of these electric cabin heaters commonly used by, oh, just about everybody here in the winter and have it blow into the pack, only using it below freezing obviously:

http://biltema.fi/fi/Autoilu---MP/Autotarvikkeet/Talviautoilu/Sisatilanlammitin/Sisatilanlammitin-1200700-W-40137/

I will also be getting one of these things to pre-heat the liquid in the heating system (and/or a gasoline heater later):

http://biltema.fi/fi/Autoilu---MP/Autotarvikkeet/Talviautoilu/Moottorinlammitin/Moottorin-lammitin-40209/

On North American imiev a with the cold weather package. There is a flap that directs air to the feet on both sides or when quick charging directs cold air from the cars AC system into the the battery. There is a servo that operates this flap. It's located on the drivers side near the accelerator pedal on the middle console. There is a picture somewhere on the forum of this. Not sure where. You can remove the servo and operate the flap manually to direct warm air from the heating system into the battery.

It is a good idea to heat the battery in very cold temps. Problem would be getting the air to circulate evenly in the pack. Also I guess it would be a plumbing job to insert the electric heater into the inlet air for the pack

If possible I think it's better to keep your car inside when temps are very cold to avoid this lithium plating issue during cold weather charge.

If you do this please let us know how it goes. You can monitor temps with canion and see how effective it is.

Hope that helps.

Don....

DonDakin, so the flap changes the airflow between driver's feet and battery? Or did I understand correctly?

I reckon forced warm into the pack should distribute rather nicely. Especially since there's just that one small outlet at the top back of the battery pack, so there might be a way to create a bit of over pressure into the pack with the heated air.

Other options I'm considering would be heat pads or this cable meant to keep pipes from freezing and attach either one to the bottom of the battery outside the pack and try to add some insulation over it, if possible.

That's correct.

Heating pads would work better but you have to remove and open the pack and the figure out how to get them in there.

Maybe pads above and below the pack on the outside would work and be much easier to install.

Don....

Is the bottom of the pack plastic or metal? If metal, it might distribute the heat well enough. Less so if plastic. In any case I'd just like to keep the pack above freezing, not heat it up any more than that.

Bottom of the pack is a steel box, with a plastic shield below that. Between those two panels is where I'd hope for electric heating pads to be worthwhile, and provide reasonably even heating, probably moreso than hot air through the footwell. Of course, my ultimate garage would have solar-heated hydronic loops in the floor, with biofuel backup heat. I know that Finnish drivers have a reputation for being the world's best on snow and ice, but please tell me that garages are common! ;-)

jray3 said:

I know that Finnish drivers have a reputation for being the world's best on snow and ice, but please tell me that garages are common! ;-)

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I wish I could tell you that they are, but while they're not exactly uncommon, not everyone has one. I for one don't have one now. If I did have a warm garage I wouldn't be so worried about the battery being frozen for long periods of time. Nevertheless, I'll do what I can to keep it warm and try to get the car unfrozen occasionally during the winter.

I think the best solution for you is to find the tube that goes to the battery. Its in front of the drive mode selector. You have to remove the plastic cover. It can deliver hot air made by the car inside the battery. You just have to find the door that opens when the car wants to put air in the battery and find a way to open the door yourself when you want. I think this is possible.

The car automatically open that door in a quick charge. You just have to find a away to open it and close it by yourself.

Thanks, Malm, that's good info. I'll have to see if Citroën has chosen to include any sort of winter package or logic that would heat the pack if it's really cold. If not, I'll have to figure out how to operate that flap so I can force some warm air in.

From what we've seen on the US 2012 models, if the car has the plumbing, it will heat the battery in the winter. Because unless you have the cold weather package (heated mirrors and battery warming system) or quick charge package (cold weather package plus a quick charge port), Mitsubishi left the plumbing, servo, and logic out that would warm the battery. Siai47 figured this out the expensive way when buying his second i-MiEV that lacked the plumbing, so he purchased a salvage i-MiEV and transplanted the entire electrical system, including the battery, from the wreck to his second car. The salvage car was an SE premium, if I remember correctly.

I don't know if it went as far as different battery packs (those with heating/cooling, vs. without) where internal plumbing is different, but the cars without the plumbing on the HVAC system didn't have the boot on the battery pack, either.

Test drove and subsequently bought the 2011 Citroën C-Zero today. It had only 10.000km on it. No-brainer, really.

I did a couple of quick charges on it and it make a loud-ish noise while doing so it definitely has the plumbing and AC pushing cool air into the pack while quick charging. Hopefully it will also push heat in while charging low in low temperatures. That remains to be seen.

Anyway. The car will be in the shop for 1-2 weeks while they fix a couple of dents and after that it's no more oil for me. Good times.

jsantala said:

Test drove and subsequently bought the 2011 Citroën C-Zero today. It had only 10.000km on it. No-brainer, really.

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Jarkko, congratulations! Do let us know how you fare when winter hits you; in the meantime, enjoy what remains of the summer!

As mentioned in multiple places on the site, here is a picture of the damper servo that directs air to the battery pack. Circled in Orange are the two screws that hold the servo in place, as well as a reference to the location of the USB port to demonstrate the location of the servo.

https://www.dropbox.com/s/t5jezlryoo1j7ze/20140917_181508.jpg?dl=0

For a long time we didn't realize that the battery cooling systems were not identical. siai47, clovi, and Jaraczs were instrumental in uncovering and discussing the mysteries. Here's one of the first - My second IMIEV does not make the normal fan noise.

More photos and discussions on this Passive Cooling thread:
http://myimiev.com/forum/viewtopic.php?p=10727#p10727

Video of battery pack from Ben Nelson:
http://300mpg.org/2013/05/05/i-miev-battery-pack-air-cooling/

Some excellent discussions by siai47 here and his cooling diversion:

http://myimiev.com/forum/viewtopic.php?p=11904#p11904
http://myimiev.com/forum/viewtopic.php?p=11858#p11858

I took a look at the pics and links and then went to look under the console. I see several screws to take the cover off and several other "covered" screws that have no means of turning them. How does one remove the "covered" screws in order to take the cover off?

I apologize if this simple question has been answered before, but...

Phximiev said:

I took a look at the pics and links and then went to look under the console. I see several screws to take the cover off and several other "covered" screws that have no means of turning them. How does one remove the "covered" screws in order to take the cover off?

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Don't know if this answers your question, but some of the fasteners in the i-MiEV can be tricky. Here's one answer from siai47:
http://myimiev.com/forum/viewtopic.php?p=12766#p12766

Thanks, I will give that a try.

If you want to remove the servo and manually force cool air to the battery, only two Phillips head screws need removed, no trim pieces... Unless you're looking for something else. I'm kind of lost on what you're wanting.

Ok, returning to this topic, I did find the actuator/servo and the two screws (and found the pics in the passive cooling topic showing the white levers) so the change looks easy enough. The question that I now have is related to the actuator/servo as it is described. What is that servo supposed to do when the levers are in their un-modified position? Or put another way, what is its present purpose?

The servo moves the damper to allow airflow into the battery when the battery warming system is working, as well as allowing cool air to flow into the pack when quick charging. The i-MiEV uses the HVAC system to manage the pack temperature.