Battery air intake

[Phximiev]

I take it that this system doesn't work while driving hence the need for the passive heating/cooling modification? What does one do with the actuator/servo once its removed? Re-install it?

I seem to recall somewhere in the forum that someone had suggested programming to do this but that the effort to work out the CAN codes was too difficult. With Canion, has this approach been re-visited?

And finally is Mitsubishi considering such a programmatic solution?

 

[PV1]

Correct. The i-MiEV only does thermal management while charging.

I'm not sure. I would think the servo would be unplugged and removed while driving and stored in the glovebox. I personally have only taken it off while charging to manually force warm air from the garage into the pack. I have yet to see the battery heater in action, though I suspect it did operate one morning where pre-heating didn't seem to warm the cabin at all.

I know work is being done to de-code the CAN bus for monitoring purposes, but I doubt that any programming can be done over it. Everything seems to be programmed using the MUT-3 tool.

As for what Mitsubishi is planning, who knows. They may be close to ending the i-MiEV in favor of newer model plug-in vehicles. The way they've been treating the US market, it seems that the i-MiEV is a test car for corporate. The original i minicar was released in 2006, and the electric i-MiEV was released in 2009-2010. But, that's just my guess.

To answer your question, Mitsubishi hasn't made any major improvements in the three model years available to the US. The only things that have changed are trim levels and which options are now standard. Oh, they also swapped Raspberry for Aqua Marine Blue. We still have the same battery pack, the same 3.3 kW charger, same everything. So, I doubt that they would make any changes to the thermal management system. The only improvement to it so far is that now it is standard on every car, and not bundled with the cold weather package, quick charge package, or premium package (2012 cars without these options have no ductwork going to the battery, no servo, and no fan in the battery pack).

 

[Phximiev]

Interesting. Ok, I spoke to another iMIEV owner in Arizona, who is not a member of this forum, and he swears that he hears a fan come one when he is driving in the heat. He thinks its the battery fan. Has anyone heard the battery fan coming on while they are driving in hot weather?

So, if the noise that I hear when I plug in the charger is for the cooling system for the charger and not the battery, when does the battery fan come on?

 

[jsantala]

There are two separate battery ventilation methods. A blower fan in the top rear of the pack, which at least on the C-Zero will always engage briefly when I plug in, and then there's the system, which activates when quick charging and uses the vehicle AC to blow cool air into the pack from the front.

 

[JoeS]

There are two separate battery ventilation methods. A blower fan in the top rear of the pack, which at least on the C-Zero will always engage briefly when I plug in, and then there's the system, which activates when quick charging and uses the vehicle AC to blow cool air into the pack from the front.

Has anyone figured out how to manually activate that battery fan? On a hot day when I know I'll have some serious climbing I'd like to be preemptive. That fan sound like it has a serious flowrate.

 

[Phximiev]

Well, I just got off the phone with the service folks at Mark Mitsubishi here in Phoenix, including their iMIEV tech, who made the following statement, to wit: the battery fan will come on and cool the battery if the AC is on. I asked if this was true of all iMIEV models and the tech said yes, if the AC is on, the battery fan will come on if needed to cool the battery.

:idea:

 

[JoeS]

I asked if this was true of all iMIEV models and the tech said yes, if the AC is on, the battery fan will come on if needed to cool the battery.:idea:

Phximiev, thank you for doing the legwork. Perhaps a (not-so) minor correction: vehicles without CHAdeMO or the cold weather package do not have a fan inside the battery compartment, nor do they have an air duct leading to the battery compartment. Somebody please correct me if that is an incorrect statement.

 

[siai47]

The bottom line on this battery cooling thing is this---- 1. If you plug in the EVSE and hear a fan start and run for a few seconds and then stop, you have hit the lottery! This means that you either have a Chadmeo connector or the cold weather package. 2. You only have battery thermal control for L3 charging where the A/C might come on during the charging session or for heating the battery during charging in cold weather conditions. 3. THE BATTERY WILL NOT HEAT/COOL UNDER ANY OTHER CONDITIONS. Therefore as these cars have a duct running from the heater floor outlet into the battery compartment there is a opportunity to control battery temps manually by removing the servo at the lower heater duct and manually opening the diverter valve to provide airflow into the battery. I leave my diverter valve in this position year round. If you place the face/floor/defrost selector (the bottom one on the heater control) half way between face and floor and leave it there the system works well. The battery is happy at temperatures about the same as people are happy at --- Summer or Winter. As you adjust blower and temperature settings to be comfortable, you are automatically setting the battery to the same temperatures. You can verify this is happening with the CAN-ION app and notice (in hot weather) a dip in temps in the pack just past the mid-point of the 66 temp sensors. This is because the ductwork in the pack puts the bulk of the airflow between the two "stacks" of modules in the pack. I have been doing this since I bought the car and have had no problem with the setup. BTW---for those of you who what to manually power the pack blower it won't do any good. First, its difficult to do as the motor is a PCM controlled device and You need to provide a canbus start and speed signal to get it to go. Secondly, and most important, without the heater diverter valve in the open position, there is no way makeup air can flow into the pack to replace the air that the blower is trying to remove. No airflow occurs when the blower starts when you first plug in the EVSE. The only purpose of the short few second run time of the blower is to purge dirt out a small filter located on the blower outlet on the top of the pack.

 

[Aerowhatt]

This is an interesting topic and one that could make a difference for me during our hot desert summers. I diverted ALL of the air into the battery duct and put the climate control blower on max output. Going under the deck in the back and reaching forward to the top vent opening on top of the battery. I could feel some air but not much. Judging by the sound and lack of significant flow I think there is a damper there as well. If so it would significantly reduce the effectiveness of trying to mediate battery temps with the cabin climate controls.

It would take a look at a removed battery pack or a spec drawing to be able to know for sure. Has anyone had an up close look at that exhaust vent to see if there is a damper in there too??? It makes sense that there would be. I would have put a closure on there if I had designed it.

Aerowhatt

 

[jsantala]

There's no damper in there, just a fan and a filter, which might be just enough to hamper air flow by itself.

Ben Nelson has a really nice video where he has taken apart an i-MiEV battery box and shows the lid with it's air cooling:

https://youtu.be/ZbV_5O7_yGk

 

[Aerowhatt]

There's no damper in there, just a fan and a filter, which might be just enough to hamper air flow by itself.

Ben Nelson has a really nice video where he has taken apart an i-MiEV battery box and shows the lid with it's air cooling:

Thanks for the link. Judging by the inlet ducting inside the pack in one of Ben's other videos. That exhaust fan at the back of the pack (or one installed beyond it) is going to have to function too in order to get even and effective temperature management of the cells.

Aerowhatt