Hybrid Battery Cooling Data

[GPSMan]

I recorded some hybrid battery internal temperature data on a 75 minute drive and compared it to what the hybrid battery coolant temperature was. Data was recorded at roughly 1 minute intervals. Outdoor Air Temperature was about 80 degrees at the start, and 78 degrees at the end. Data came from the OBDII port using a ScanGuageIII.

One of the early issued (2022) service guides stated HV battery active cooling begins at above 95 degrees Fahrenheit. This is the point the water is supposed to be chilled using air conditioning refrigerant.

On two occasions prior to this, I noticed my truck behaved a little differently.
Today was the first time I set out to record the data, but all three instances were similar.
In my truck, chilled water starts going to the battery when the battery pack temperature hits 104 to 106 degrees Fahrenheit.

Below this temperature, the battery temperature and the coolant temperature are the same. The water may be circulating and just radiating heat. This is probable, but I have not confirmed this. Below 104 degrees, the water temperature and the battery temperature are in equilibrium. In the chart, you can infer that active chilling occurs when there is a delta (divergence) in water temperature, noted by the blue arrow. The green arrow is the approximate point I parked the truck in the driveway but left the key to run. So little or no addition battery heat was generated beyond the green arrow.

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[SR-71]

I’m also curious what the cold weather battery heating graph will look like

 

[GPSMan]

Additional notes*:

On an 80 degree day:

One stop from approximately 35 mph to 3 mph using "Low" or "Sport" or "Tow Haul" will add about 3 degrees of heat to your battery pack.

One stop in Eco mode will add about 2 degrees of heat to your battery.

One stop in Normal mode will add about 1.5 degrees.

One stop in Slippery mode will add about 1 degree of heat to your battery.

Driving in "Low" all the time in warm or hot weather is not advised (by me).
Your battery will work to protect itself with active cooling, but active cooling will cost some non-zero amount of gasoline. And your battery will run on the hotter end of the "acceptable" spectrum.
It won't blow up or catch fire (I don't think). But I see no benefit either.
HTH

*assumes you let the truck coast for most of the distance. Harsh braking in any mode will heat the battery about 3 degrees per instance.

 

[GPSMan]

You can see seven distinct dips in cooling water temperature.
I wonder if this is the "zone valve" for the air conditioning refrigerant opening and closing seven times.

I had air conditioning running to the cab the whole experiment at a low setting. I never detected the battery loop "stealing" any of my cab cooling. Cab air was icy cold the whole time.

 

[rivermaverick]

I recorded some hybrid battery internal temperature data on a 75 minute drive and compared it to what the hybrid battery coolant temperature was. Data was recorded at roughly 1 minute intervals. Outdoor Air Temperature was about 80 degrees at the start, and 78 degrees at the end. Data came from the OBDII port using a ScanGuageIII.

One of the early issued (2022) service guides stated HV battery active cooling begins at above 95 degrees Fahrenheit. This is the point the water is supposed to be chilled using air conditioning refrigerant.

On two occasions prior to this, I noticed my truck behaved a little differently.
Today was the first time I set out to record the data, but all three instances were similar.
In my truck, chilled water starts going to the battery when the battery pack temperature hits 104 to 106 degrees Fahrenheit.

Below this temperature, the battery temperature and the coolant temperature are the same. The water may be circulating and just radiating heat. This is probable, but I have not confirmed this. Below 104 degrees, the water temperature and the battery temperature are in equilibrium. In the chart, you can infer that active chilling occurs when there is a delta (divergence) in water temperature, noted by the blue arrow. The green arrow is the approximate point I parked the truck in the driveway but left the key to run. So little or no addition battery heat was generated beyond the green arrow.

Interesting - it's been a bit warm here for the last month, 118° plus! I've notice the AC takes longer to cool the cab than non-hybrid vehicles I've driven in similar conditions. I hadn't thought about it cooling the battery.

 

[MakinDoForNow]

You can see seven distinct dips in cooling water temperature.
I wonder if this is the "zone valve" for the air conditioning refrigerant opening and closing seven times.

I had air conditioning running to the cab the whole experiment at a low setting. I never detected the battery loop "stealing" any of my cab cooling. Cab air was icy cold the whole time.

Someone, maybe you, posted that there were two positive? wires to compressor motor. Poster did not say if they were connected to same terminal. I am thinking maybe one is for battery chilling loop and other for cab cooling loop so might be used to control speed of compressor motor to increase or decrease compressor out put to what's needed for needed capacity. Once in mine when I readied my truck AC was off and truck temp showed 99°F I heard the compressor running relatively slow as one could almost count the clicks. I assumed it was the battery being chilled.but I have no actual way to tell for certain. Maybe it was just doing checks for operation.

 

[Shay]

I never detected the battery loop "stealing" any of my cab cooling. Cab air was icy cold the whole time.

I have here in Phoenix on extremely hot days with 115 -120° temperatures that when the system is cycling its various cooling procedures, that the AC does go dim and then gets colder and back and forth in a way that's clearly part of a mode change

 

[huunvubu]

Someone, maybe you, posted that there were two positive? wires to compressor motor. Poster did not say if they were connected to same terminal.

"two positive? wires to compressor motor" Uh What !!!

The compressor in the Hybrid Maverick is run via the HV Battery and changed to AC by electronics

Note the Bright Orange wiring going to the compressor.

How a Hybrid A/C Compressor Works

 

[MakinDoForNow]

"two positive? wires to compressor motor" Uh What !!!

The compressor in the Hybrid Maverick is run via the HV Battery and changed to AC by electronics

Note the Bright Orange wiring going to the compressor.

How a Hybrid A/C Compressor Works

Makes more sense, I have no idea what he was looking out.

 

[MakinDoForNow]

I have here in Phoenix on extremely hot days with 115 -120° temperatures that when the system is cycling its various cooling procedures, that the AC does go dim and then gets colder and back and forth in a way that's clearly part of a mode change

I have In 106-108° AC at 73° had chill on and off with ac on auto. Not so with ac on and auto off.

 

[GPSMan]

Revision:

I DO NOT think the HV battery coolant circulates continuously. I think it only circulates when it deems necessary.

On multiple hot days, I've seen something like this: 90 degree day, but truck parked in a hot parking lot in full sun. The "coolant" was warmed to 109 (or more precisely the sensor location was heated to 109) from the hot parking lot.

After a 10 minute / 3 mile drive this value did not change, the coolant temperature did not go down and the battery temperature did not go up.

I had the A/C blasting for those 10 minutes.

In the 2005-2008 (at least) Escape Hybrids the battery would "opportunity cool". If the human was using A/C the battery would chill from 85°F down to 75°F. If the human was not using A/C the battery would "opportunity cool" between 85°F and 95°F if the engine was running for other reasons. It would still allow EV drive mode. At 96°F and above the engine would stay on. It had an engine belt driven compressor. Those were NiMH cells and they were babied more than the Li based cells in the Maverick, which I "think" don't get any A/C until about 105°F.

 

[GPSMan]

While the above data seems a little on the warm side, a battery company not affiliated with Ford has this to say:

 

[TedTX]

Storage temps look bad, we have many hours above 95. I know its bad to store in elevated heat but not that low of a high temperature. I estimated based on killing laptop/phone battery life by leaving them inside truck during summer it was about 120+

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