Battery Preconditioning: Some measured data.

[SpaceEVDriver]

We all know that Ford doesn't really provide a great tool for warming up your battery in the cold before a long drive and that it would be nice if we could force this to happen when we need it to. The departure time doesn't do a great job if we don't have a regular schedule or if we're going to be leaving on a spur-of-the-moment trip.

Based on this thread: DCFC preconditioning is it coming????, I monitored the coolant temperature during a trip I took yesterday which included a request to the Ford navigation to take me to a DCFC about halfway through the ~250 mile trip. Those data indicate to me that DCFC battery preconditioning is here, if not well-advertised.

This is a messy chart that shows the ~30 mile preconditioning of the battery before DCFC charging. You can read the more detailed description in this comment to the above thread.

A plot of just the HVB Coolant Inlet Temperature from that drive is here. Note that I started the car about 12 minutes before we left, but didn't use a departure time.

The peak temperature during the first hundred or so miles was about 61 degrees F.
Then we got to within 30 miles of the DCFC and the car bumped up the coolant temperature to 107 F, and it hit 117 F during charging.
Afterward, the battery temperature stayed high because of thermal inertia.

This morning I was reading this thread: Advice: Preconditioning and I got to wondering... What if I asked the car to navigate to the nearest DCFC while it's sitting on the charger at home?

The data in the chart below indicate that giving Ford a DCFC destination will bump up the coolant temperature beyond what it did for me when I just started the car yesterday morning and I suspect that this could be used to condition the battery for driving in the cold.

In this case, I went out to the car, started it up, set a destination and asked it to take me there. But I didn't unplug the car or do anything else during the wait time. Because it's on a 120V Basic AC charger, it lost range while doing this (about 1.5%). I would probably only do this if it were really cold or if I were on the 240-volt Level 2 charger.

What I haven't done is test the departure time settings. Does that also bring the temperature up to 93 F?
I'll have to wait for the battery to cold soak again before it would make sense to gather those data--or someone else could show us their results.

Of course, this would probably only work if there's a DCFC within the distance limit...

 

[ChuckA]

I think the remote start should precondition the battery. I compare it to the preignition on a smoker prior to it reaching temperature.

 

[SpaceEVDriver]

I think the remote start should precondition the battery. I compare it to the preignition on a smoker prior to it reaching temperature.

It doesn't, though.
The early data in my first graph from yesterday show that the remote start only brought the battery up to about 53 degrees F before I plugged in my Car Scanner. That's better than the exterior temperature of about 30 degrees F, but nowhere near as good as 93 degrees F after I'd set the destination today. Both times the exterior temperature was around 30 degrees F.

 

[Murse-In-Airy]

Thanks for posting the graphs. Guess I’ll have to start using built in navigation if I’m planning a DCFC stop.

 

[SpaceEVDriver]

Thanks for posting the graphs. Guess I’ll have to start using built in navigation if I’m planning a DCFC stop.

Here's more direct evidence that plugging a DCFC charger into your built in navigation will precondition your battery.

The red line is the charge power limit as set by the car. The blue line is the inlet coolant temperature. The green line is the power to/from the HVB.


We were about 30 miles away from the DCFC just before 14:07, which is when the inlet coolant temperature started climbing. The charge power limit lagged a bit, but began climbing a little while later.

I'm pretty confident that the car will precondition the battery for faster charging if you tell it you're on your way.

 

[AZBill]

It will not precondition as much without the DCFC planned because for driving or charging on L2, it does not need that higher temperature to work normally. The higher temp is needed for high current charging.

 

[Mach-Lee]

We all know that Ford doesn't really provide a great tool for warming up your battery in the cold before a long drive and that it would be nice if we could force this to happen when we need it to. The departure time doesn't do a great job if we don't have a regular schedule or if we're going to be leaving on a spur-of-the-moment trip.

Based on this thread: DCFC preconditioning is it coming????, I monitored the coolant temperature during a trip I took yesterday which included a request to the Ford navigation to take me to a DCFC about halfway through the ~250 mile trip. Those data indicate to me that DCFC battery preconditioning is here, if not well-advertised.

This is a messy chart that shows the ~30 mile preconditioning of the battery before DCFC charging. You can read the more detailed description in this comment to the above thread.

A plot of just the HVB Coolant Inlet Temperature from that drive is here. Note that I started the car about 12 minutes before we left, but didn't use a departure time.

The peak temperature during the first hundred or so miles was about 61 degrees F.
Then we got to within 30 miles of the DCFC and the car bumped up the coolant temperature to 107 F, and it hit 117 F during charging.
Afterward, the battery temperature stayed high because of thermal inertia.

This morning I was reading this thread: Advice: Preconditioning and I got to wondering... What if I asked the car to navigate to the nearest DCFC while it's sitting on the charger at home?

The data in the chart below indicate that giving Ford a DCFC destination will bump up the coolant temperature beyond what it did for me when I just started the car yesterday morning and I suspect that this could be used to condition the battery for driving in the cold.

In this case, I went out to the car, started it up, set a destination and asked it to take me there. But I didn't unplug the car or do anything else during the wait time. Because it's on a 120V Basic AC charger, it lost range while doing this (about 1.5%). I would probably only do this if it were really cold or if I were on the 240-volt Level 2 charger.

What I haven't done is test the departure time settings. Does that also bring the temperature up to 93 F?
I'll have to wait for the battery to cold soak again before it would make sense to gather those data--or someone else could show us their results.

Of course, this would probably only work if there's a DCFC within the distance limit...

I think the preconditioning range is only 18 miles (30 km), did you happen to note the exact place the coolant temp shot up?

 

[SpaceEVDriver]

I think the preconditioning range is only 18 miles (30 km), did you happen to note the exact place the coolant temp shot up?

I will have to look at the data in a spreadsheet to get the lat/lon location and compare with a real map. I've been guesstimating the distance.

 

[SpaceEVDriver]

It will not precondition as much without the DCFC planned because for driving or charging on L2, it does not need that higher temperature to work normally. The higher temp is needed for high current charging.

Right. The question that spurred my tests was whether there's the full-on preconditioning before arriving at a DCFC (if one plugs the DCFC into their onboard navigation). I think there is.

Then I began to wonder if we could use that same capability to cause the car to do a better job of conditioning (warming) the battery before going on a long trip or before going on a trip when it's cold. I think we can, and I think it does a bit better job than setting a Departure Time.

 

[SpaceEVDriver]

I think the preconditioning range is only 18 miles (30 km), did you happen to note the exact place the coolant temp shot up?

Okay. You're correct. The fidelity of the CarScanner data isn't great, but I wasn't moving too quickly. The first time the temperatures clearly start to climb the car is around 19 miles from the DCFC according to the car's GPS. However, the way CarScanner does it's round-robin polling, sometimes things don't update quickly enough, so 18 miles seems correct.

 

[Mach-Lee]

Okay. You're correct. The fidelity of the CarScanner data isn't great, but I wasn't moving too quickly. The first time the temperatures clearly start to climb the car is around 19 miles from the DCFC according to the car's GPS. However, the way CarScanner does it's round-robin polling, sometimes things don't update quickly enough, so 18 miles seems correct.

30 km is 18.641 miles, so yeah 18-19 mi range approximately, just wanted to verify it's 30 km. My view is that isn't long enough to get the battery up to a desirable temp of 70ºF or higher for full speed DCFC right off the bat. Your data shows it still had to heat the battery for a while after plugging in.

The DCFC speed is limited to about 60% of the regen/charger power limit. Ideally you should arrive at the DCFC with a regen limit of 200 kW (so you can charge at 120 kW) and it should start at the right time so that occurs. If that's too complicated to implement, I will advocate for the range threshold to be doubled to 60 km or greater.

 

[SpaceEVDriver]

30 km is 18.641 miles, so yeah 18-19 mi range approximately, just wanted to verify it's 30 km. My view is that isn't long enough to get the battery up to a desirable temp of 70ºF or higher for full speed DCFC right off the bat. Your data shows it still had to heat the battery for a while after plugging in.

Here's a zoom to just before and just after I started charging. The battery is at 75F when I arrived at the DCFC, and had been at 75 F for a few minutes. I still only got a minute or two at 120 kW and then it dropped to ~100 kW for a bit before making its way down. I don't believe I have any control data for a similar scenario (outside temperatures, etc) without the DCFC navigation.

 

[Gullwingdmc]

Thank you for doing all this research!!

 

[SpaceEVDriver]

Thank you for doing all this research!!

You should check out @Mach-Lee's tests too.

https://www.macheforum.com/site/thr...ting-taking-requests.24393/page-7#post-570808

 

[SpaceEVDriver]

And here's the full plot of the HVB temperature. It's clear that the car started warming the battery right at that ~30 km (18 mile) range (just before 14:07). I started charging at about 14:39. So either the battery cooled off from the target temperature or the car overshot the target temperature.

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