Battery Vents and traction fans

[Russael]

Has anybody ever felt around your battery vents while the fans were in operation to see if you could feel any air being pulled in or pushed out somewhere?

 

I haven't had any issues with the car kicking over to hybrid operation nor have I had any instances of the car slowing charging, but I had gone outside to my garage after driving about 25 miles on batteries today (92 degrees outside, no climate).  Well, after leaving it charge about 2 hours, we had a rain storm and I went out to the garage to go take care of something I thought of, and heard the fans whirring away in the car.

 

The garage was still really warm, so I opened the door to let some cool air in, and I decided to pop the trunk of the car to let some heat out of that too.  It was really warm in there, but not where I expected.  It was really hot over top of the battery (air temp), so I decided to try to find the air vent outlets.  I pulled up the tool cover and then pulled out the tool tray (the thing with the air compressor and 120v charger), and found 2 traction fans (squirrel cage blower style).  Only one appeared to be on, and both of them seem to have outlets right under the tray.  One looks like a horn with no grille (you can stick your fingers in it), the other one has a grille attached.  But to my surprise - I felt NO air coming from either vent nor could I feel air being sucked in.  So now I'm starting to wonder if something is blocked somewhere.  Fans were going, felt nothing being pulled from the cabin, felt nothing being vented to the trunk.

 

I did find the 'end of life, battery removal' document for the Fusion/MKZ battery packs and took a look at those, but neither really indicate air flow direction.  They do indicate 'inlet' and 'outlet' but it's a bit on the confusing side since it'll show the hybrid and energi.  So, I'm starting to wonder if my own vents are blocked in some way.

[murphy]

The air intake is the U shaped grille on the rear deck.  Use a flashlight to see if you can see down into the plastic pipeing.  There was a report either on this forum or the Blue Oval forum of someone finding theirs blocked.  The air conditioning really should be run when it is that hot to provide cool air for the battery.

[Russael]

I thought it was the intake, but wasn't sure, as it was REALLY warm up there and I couldn't feel any air being pulled in (I don't expect a hurricane, but I figured I would've felt something).  But I did find one of the exit vents - it's behind the passenger rear seat near the bottom (3 oval slits in the carpet).  Yes, it vents in to the cabin rather than in to the trunk.  I could feel air coming from that, so I'm now satisfied that nothing is blocked.  I just found it bizarre that there ARE vents in the trunk and the cabin.  Perhaps the system is more finessed than I thought and the car will choose where to vent... either the trunk or the cabin.  Can't find any documentation on it though.

 

I turned the car 'on' while it was plugged in, which makes at least one of the fans come on too so I was able to hunt for it.

Edited July 10, 2013 at 12:16 AM by Russael

[larryh]

Pull down the smaller section of the rear seat.  You can feel the fans blowing air out from the battery behind the seat through the slots to the box surrounding the battery.

 

I don't feel much air being sucked in from the vent on the rear deck and I don't feel any air being vented into the trunk.

[Russael]

Hmmm... perhaps that vent behind the rear seat is connected to the passenger side blower.... and I'm starting to believe that the battery charger (which is also located on that side) has its own dedicated fan.  The fan on the driver's side must be for the batteries, but that wasn't running while the car was charging nor when I pulled in the garage after my drive.  I'm also wondering if the car will reverse the directions of those fans to suit what it needs...

 

As far as driving around with climate, that puts another big load on that battery and the faster you drain it, the more it's going to heat up.  So it's sort of a vicious cycle where you're cooling the air it needs, but making the battery warm up even faster due to the draw.

 

It's very rare when Michigan gets 100+ degree days... haven't had any in a few years.  We've had high 90's but Michigan seems to have been teleported to where Washington State is since we've had rain every friggin day for WEEKS.  Last year, it was desert mode and I think I only cut my grass 5 times since it all dried up and went dormant.  So presently, I don't expect to see the car turn on the motor with temps where they're currently at.

Edited July 10, 2013 at 12:38 AM by Russael

[Zman11]

Are the fans supposed to only run when hot? I had my Fusion for a month and I can hear the fans on the rear shortly after plugin in. 

[Russael]

The Energi has 2 fans where the Hybrid only has 1.  I BELIEVE 1 fan is for the battery (takes air from the U shaped plastic vent in the rear deck and vents it in to the trunk) and the second fan is for the battery charger itself (takes air from the trunk and exhausts in to the cabin).  I have not yet heard or felt the battery fan go, but the charger fan is always on when I plug it in and will stay on for about 5 minutes after charging is complete.

[mczajka]

The fans always go on when charging, but I've noticed what appear to be two modes. Regular and super. In this heat, my fan also goes on when I stop at a traffic light. With the heat in MD today, I'm going to park outside tonight and try the value charging. I hope it works. I don't think it's good to be charging in a very hot garage, even though it would probably work.

[jdoconn]

The fan intake in the Fusion Energi which runs most of time when I charge is located under the rear bumper aft of the muffler.  There is a metal screen over it.  Only issue I see is charging right after running the engine for extended period of time, you would be pulling in air heated by the hot muffler and exhaust piping.  With the hybrid I'm sure Ford figures the engine runs infrequently that this is not an issue.  But, interstingly they put a heat shield on the bottom of the plastic bumper which is aft of the fan intake. Hmm.

[Griff]

The fan intake in the Fusion Energi which runs most of time when I charge is located under the rear bumper aft of the muffler.  There is a metal screen over it.  Only issue I see is charging right after running the engine for extended period of time, you would be pulling in air heated by the hot muffler and exhaust piping.  With the hybrid I'm sure Ford figures the engine runs infrequently that this is not an issue.  But, interstingly they put a heat shield on the bottom of the plastic bumper which is aft of the fan intake. Hmm.

Wouldn't that subject the vehicle passengers to carbon monoxide poisoning when it kicks on while driving on really hot days?

[murphy]

But, interstingly they put a heat shield on the bottom of the plastic bumper which is aft of the fan intake. Hmm.

The heat shield is for the muffler which is very close to that area.

[kjhansen]

Hopefully someone out on this blog can answer my questions. I have read through this entire blog and still have questions.

I live in CA near Sacramento and we get several days of 100F+ in the summer, and I'm concerned my car isn't getting adequate battery cooling.

 

Here is what I have observed regarding the battery cooling systems on my 2016 Fusion Energi SE;

1) The Traction Battery cooling fan is located on the drivers side in the trunk. It draws air from the U shaped inlet on the shelf below the rear window and expels it into the trunk. It has a high and a low speed.

2) The Inverter cooling fan is located on the passengers side in the trunk. It draws air from either under the rear of the car (outside) or inside the trunk via a flapper door and expels it behind the base of the rear passenger side seat back. It seems to have only one speed.

 

Here are my questions;

A) How can the battery be cooled adequately if the hot air from the battery is expelled into a closed trunk, in which the battery is contained??? This explains why the trunk is so very warm after a charging cycle.There appears to be no way for this super heated air to escape the trunk. I have been leaving the trunk lid opened and removed the black plastic "scuff shield" from the trunk so the hot air can escape. Why is there no flapper valve to direct the hot air out the bottom of the car or into the trunk? I'm assuming the hot air from battery cooling is used to heat the Inverter when ambient temperatures are cold.

B) Why didn't Ford route the ducting for both of these fans such that it would free up more trunk space? Both could have been tucked under the battery cage, freeing up 3" - 4" of trunk depth. Not much you say; yes, but it would allow a standard carry on bag to be stood up in the trunk, allowing more bags to be placed in the trunk. Why must the Inverter fan draw air in from behind the muffler, why no ahead of the muffler?

 

Thanks in advance for your response.

Ken

[larryh]

See this post regarding how the venting for the HVB works:  http://www.fordfusionenergiforum.com/topic/1683-obd-ii-data-for-hvb/?p=21758.

 

While charging, the car draws in outside air from a vent located under the long black tube in the picture.  The inlet is under the car near the bumper.  The hot air is vented into the passenger compartment behind the rear passenger seat as you stated.  The vents in the rear deck of the car are used when the car is running and the passenger compartment is cooler than outside. 

 

Air cooling is not all that effective in cooling the HVB.  Liquid cooling would do a much better job.  The HVB is going to be approximately 10 F degrees higher that the outside temperature.   The best way to deal with high temperatures is to keep the State of Charge of the HVB low.  Delay charging the car until you are ready to go.   Don't keep the battery at a high SOC any longer than necessary.  It is the combination of high SOC and high temperatures that cause rapid battery degradation. 

Edited June 29, 2016 at 11:34 PM by larryh

[larryh]

Note that most of the heat generated while charging comes from three chargers inside the car used to charge the HVB.  Their temperatures get well over 150 F.  It is not the HVB by itself that is generating all the heat. 

 

If it is 100 F outside, the HVB temperature is probably around 110 F.  At those temperatures, the HVB will start to degrade rapidly when the SOC of the battery as reported by MFT/MFM exceeds 40%.  It is alright to charge the battery, but use the charge up right away so that the average SOC of the battery over a day is less than 40%. Delay charging (using Value Charge) until early in the morning so it finishes just before your commute to work.  Since the car does not do a good job of managing the HVB temperature and SOC, the owner is going to have to do it.  If you don't take steps to mitigate HVB degradation, the battery capacity could be reduced to less than 80% in two to three years as other have experienced. 

 

In addition to delaying charging so it completes right before you leave and avoiding sustained high battery charge, there are some additional steps you can take.  Park the car in cool locations out of direct sunlight.  Moderate driving.  Use EV later mode when driving on the freeway.  If it is really hot (>115 F), consider not charging the car at all and drive in hybrid mode.  If you don't need a full charge for your trip, then only put in enough charge to complete your trip. 

Edited June 30, 2016 at 09:48 AM by larryh

[kjhansen]

From reading through all the responses on this topic, it is clear several owners have experienced battery overheating at outside air temperatures of 100F or greater. Specifically, if you fully charge the car when the outside air temperatures is 100F or greater the car will not run in EV Mode. Also, if you use EV Later Mode to save the battery for use later and the air temperature is 100F+ it will not work.

 

I have measured the battery case temperature and it is 115F which is just above the maximum allowable temperature for recharging Li-Ion batteries before significant capacity degradation occurs. Note; this is case temperature; I'm assuming the batteries are much hotter. I suspect an over temperature cut off is being reached which is disabling EV Mode. I don't understand why Ford doesn't have an over-temp cut off for charging as well as discharging? Maybe, they do and it is a much higher temperature?? This is potentially a fire hazard. There is no information available (that I can find) regrading these temperature cut offs.

 

I have taken my Fusion Energi into the dealer twice now for this issue and they haven't been able to duplicate the issue. So, as far as their concerned it is not an issue and thus not reportible to Ford. In Sacramento, CA where I live we have at least 20 100F+ days per year (probably more like 30 - 40 days this year), so this significantly limits the usability of EV Mode. Not to mention the degradation to the battery life. I have also written to Ford Customer Care about this with no satisfaction. Hmm, I guess I can try BAR (Bureau of Automotive Repair), since I did try to have it fixed twice?

 

I'm now relegated to only charging at 3:00AM when it is cooler and never charging during hot days which is pretty much all summer. I also, tilt the right rear passengers seat forward, open both front windows and open the trunk and pull up the foam form (that contains the air pump and 115V charger). This is to promote better air flow when charging.

 

Since it appears there is no way to get Ford to fix this has anyone considered ducting the left side battery cooling fan outlet to outside the trunk? It could be routed similarly to the way the Inverter cooling inlet is routed (behind the muffler heat shield. I have looked on Youtube and Toyota has the battery cooling air exit the car that way on the Prius Plug In Hybrid.

 

I'm looking forward to your responses.