Battery preconditioning with GPS ineffective in cold weather

[Matstar]

Little test today to see the preconditioning with GPS behavior at low temperature.

Unfortunately it was not a success.

Cabin already hot at 20C (68F)fan on auto 1. At highway speed, outside temperature -5C (23F), battery temperature between -1C and 5C (30F to 41F).

I enter a nearby fast charger into the GPS to start preconditioning. The coolant does not rise in temperature to warm the battery. I turn off the cabin heating and suddenly the temperature of the coolant starts to rise. I restart the cabin heating, the coolant temperature drops immediately. So unable to heat battery and just keep the heat in a already heated cabin.

In conclusion, the reduced power capacity of the Mach E heating system does not allow you to take advantage of the preconditioning during a road trip. And this when it’s most important… when it’s cold.

Maximum charging speed of 42Kw on a 350Kw charger.

Well done Ford

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[luckie]

So when you write GPS you are referring to using the built in Ford Navigation system and choosing a charger from the list provided far in advance like 50 miles, of approaching the charging station?

This is interesting and useful information, appreciate it, and as a result just have questions.

 

[Mach-Lee]

Yeah, it won’t even try if the cabin heat load is too much. When it’s working, it switches the diverter valve between cabin, and cabin+battery every few minutes. So you will notice large swings in coolant temp.

The heater just isn’t big enough to move the needle very far on battery temps. The heater should have been 2-3x bigger to successfully heat both cabin and battery simultaneously. Ford also shouldn’t allow the battery temp to get that cold while parked IMO.

 

[Matstar]

So when you write GPS you are referring to using the built in Ford Navigation system and choosing a charger from the list provided far in advance like 50 miles, of approaching the charging station?

This is interesting and useful information, appreciate it, and as a result just have questions.

Exactly

 

[AZBill]

GM and Rivian are using motor heat to warm the battery during preconditioning, instead of just a resistor. GM also uses a heat pump for the cabin.

 

[Matstar]

Yeah, it won’t even try if the cabin heat load is too much. When it’s working, it switches the diverter valve between cabin, and cabin+battery every few minutes. So you will notice large swings in coolant temp.

The heater just isn’t big enough to move the needle very far on battery temps. The heater should have been 2-3x bigger to successfully heat both cabin and battery simultaneously. Ford also shouldn’t allow the battery temp to get that cold while parked IMO.

It's amazing how Ford failed when designing this car for cold weather.

 

[SWO]

GM and Rivian are using motor heat to warm the battery during preconditioning, instead of just a resistor. GM also uses a heat pump for the cabin.

Has anyone confirmed that Ford doesn't? I mean, the motors don't have a separate cooling loop - why would waste heat not be going to the battery? Or is that something people are inferring from OBD2 data?

Rivian also has even bigger thermal issues cooling their pack during DCFC last I read...and ultium is just a mess it seems. Tesla seems do it well, but they also send coolant directly to the motors, which I don't really care for.

 

[Mach-Lee]

Has anyone confirmed that Ford doesn't? I mean, the motors don't have a separate cooling loop - why would waste heat not be going to the battery? Or is that something people are inferring from OBD2 data?

Rivian also has even bigger thermal issues cooling their pack during DCFC last I read...and ultium is just a mess it seems. Tesla seems do it well, but they also send coolant directly to the motors, which I don't really care for.

The motors do have a separate cooling loop than the battery on the Mach-E. So no heat transfer is possible. Can’t heat the battery with the motors.

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