Hybrid Maverick Cooling Systems

[SuperDave71]

There was some discussion in another thread recently that got me thinking, so I did some research and wanted to post some info i found for further discussion.

I tracked down diagrams for both of the hybrid cooling systems. The pictures are from a friend who works at a local ford dealership. He provided me with diagrams for both systems as well as a general description of the components. The comment that got me thinking was that there is at times the possibility of cross flow between the two systems for heat management/mitigation. The Ford hybrid drivetrain is relatively new to me. I have a lot of knowledge of Fords diesels, most recently the 6.7 powerstroke. It also has two cooling systems, and it seems there is a lot in common. Both are independent of each other. Separate heat exchangers, pumps and reservoirs. They are not interconnected and operate at different design temperatures to accomplish different tasks. The primary ultimately handles engine cooling and cabin temperature. The secondary handles other component temperature management.

In my first Maverick hybrid I had a failure of the exhaust heat exchanger. It was covered under warranty. While I waited months for a replacement I was under the assumption that its purpose was to warm the battery in cold weather. That is NOT the case. The exhaust heat exchanger is in the primary cooling system and is responsible for keeping and getting as much heat as possible into the primary system in cold weather to keep the engine temperature warm and stable, and keep heat in the cabin. All heat in the secondary system comes from electrical components in that system. The secondary system (battery mostly) can also be cooled via a heat exchanger that interfaces with the HVAC system in hot weather. There are two coolant pumps in the secondary system, and those pumps can independently regulate the temperature of motor electronics and battery temperature with out the use of valves. The only valve in the system is on the battery coolant loop that brings the coolant cooler (HVAC) online.

I’m sure I might have some minor errors in here, but I think for the most part this is a good overview, feel free to add other sources to help increase all of our knowledge.

Dave

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[GPSMan]

Yes.

But

Look at hose 23 and hose 24

It's not really clear but looks like exhaust heat CAN help warm the battery. But I'm gonna say from experience it does not at least at 32°F and above.

 

[Oscarcat]

My take-away is, given the importance of cooling to the ICE and hybrid components, changing the coolant with factory spec coolant at recommended intervals is very important to get the max life out of various components.

 

[BlueSpec1]

Saw mention of Motor Cooling in the DC/DC module's operation:
The DCDC is liquid cooled by the electric motor cooling system circuit. The electric motor cooling circuit uses an electric motor diverter valve that acts as a system thermostat, allowing the coolant to flow within the motor circuit while the motor warms. As the coolant warms, the diverter valve slowly opens to allow coolant flow to the radiator.

 

[srf512]

Dave, thanks for sharing. This is great stuff!

 

[svogt302]

Interesting information, Thanks.
I put an OBD2 gauge on mine & find even after a long run, mine runs very cool, like 150-160 degrees & haven't found a spec as what it should be.
Any thoughts?

 

[GreyCacti]

So there is no active heating for the battery in the winter? The hoses only cool parts, not heat them?

 

[GPSMan]

Interesting information, Thanks.
I put an OBD2 gauge on mine & find even after a long run, mine runs very cool, like 150-160 degrees & haven't found a spec as what it should be.
Any thoughts?

You need to be more specific. What is 150-160?

Example:
Engine coolant runs 180 to 190 when fully warmed up on the highway. But with short trips and city drive it rarely gets that warm.

Transmission eCVT of 140 to 160 is normal for mine.

HV Battery runs 90-100°F most of the time city driving, cooler on the highway (battery does not do much work in highway conditions).

Motor and Generator are all over the map depending on load.

 

[Clarence Roller]

There was some discussion in another thread recently that got me thinking, so I did some research and wanted to post some info i found for further discussion.

I tracked down diagrams for both of the hybrid cooling systems. The pictures are from a friend who works at a local ford dealership. He provided me with diagrams for both systems as well as a general description of the components. The comment that got me thinking was that there is at times the possibility of cross flow between the two systems for heat management/mitigation. The Ford hybrid drivetrain is relatively new to me. I have a lot of knowledge of Fords diesels, most recently the 6.7 powerstroke. It also has two cooling systems, and it seems there is a lot in common. Both are independent of each other. Separate heat exchangers, pumps and reservoirs. They are not interconnected and operate at different design temperatures to accomplish different tasks. The primary ultimately handles engine cooling and cabin temperature. The secondary handles other component temperature management.

In my first Maverick hybrid I had a failure of the exhaust heat exchanger. It was covered under warranty. While I waited months for a replacement I was under the assumption that its purpose was to warm the battery in cold weather. That is NOT the case. The exhaust heat exchanger is in the primary cooling system and is responsible for keeping and getting as much heat as possible into the primary system in cold weather to keep the engine temperature warm and stable, and keep heat in the cabin. All heat in the secondary system comes from electrical components in that system. The secondary system (battery mostly) can also be cooled via a heat exchanger that interfaces with the HVAC system in hot weather. There are two coolant pumps in the secondary system, and those pumps can independently regulate the temperature of motor electronics and battery temperature with out the use of valves. The only valve in the system is on the battery coolant loop that brings the coolant cooler (HVAC) online.

I’m sure I might have some minor errors in here, but I think for the most part this is a good overview, feel free to add other sources to help increase all of our knowledge.

Dave

I read all of this and the comments, Even more than before, I want my 1964 Galaxie 500, 390, four barrel, four speed back. I could pass everything but gas stations!

 

[GPSMan]

Today was the coldest my Maverick has been 32°F (0°C).

Using the ScanGauge there was no external heat added to the HV Battery. The HV battery fluid did not circulate, and just driving in stop n go city traffic the battery warmed via internal resistance from 34°F to 84°F in 30 minutes.

 

[basicUse]

I am guessing here, but I think the engine does whatevery engine does and operate in "closed loop" mode when cold. The coolant is NOT flowing pumps are off until the engine heats its coolant enough then the pumps open the heat the rest of the fluid in cold with fans off, then at temp the fans are on and cooling as usual. They have specific bypasses and controls in engine to do this. I also think with the 2 reservoirs next to each other that the engine reservoir coolant might heat it's neighbor the battery coolant reservoir.
As for coolant life it really lasts 10-15 years and beyond. P-OAT coolant is a long life coolant. the oat Toyota stuff i have seen go for over 20 years on used cars never changed. but I would change it too if I ever keep something that long and figure out how to burp it. The days of DEXCOOL are long gone thank god.

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