My winter Mustang Mach-E project

[Mach-Lee]

Yeah I've seen the HVB not maintaining the LVB at 15% or 12% depending on who you ask. The LVB engaging the DC/DC for top-off in my logging is in the 11V range on no-load.

I guess the problem I have is that there's mltiple different SOC charts based on voltage. Some show overlapping SOC ranges and higher/lower values like this: https://workshoppist.com/agm-battery-state-of-charge/

The data Rick is collecting would allow someone to generate a Mach-E specific SoC chart. However I think the % 12V SoC parameter is based off battery energy (Wh) and temperature instead of voltage. Voltage is used to update the SoC during off-state rest periods, but otherwise wouldn't correlate under load because of internal resistance.

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[Jiji]

Back with the improved trip report, here are the details:

The two items to note are the delta EtE from the vehicle and my calculated value which integrates the HVB power (actually the HVB voltage and current as the MME does not report a power value). Pretty close so nothing to see here.

The second is the efficency, here is the MME report from the same trip:

All three values, distance, elapsed time, and efficiency are spot on so looks like my calculations are good and I can move on to visualizing this stuff and having a database of drives that can be used to see the improvement as we move into spring and then summer.

 

[SpaceEVDriver]

I greatly appreciate this work. I will be taking advantage of your efforts. There may be things I change once I have my vehicle. Once I start analyzing, I'll likely want things to be customized for my needs. Your work, though, is foundational to my plans, so thank you for making this all open and available for others to use.

 

[mkhuffman]

There's other members here like Mach-Lee who have also confirmed 15% SOC. How are you determining when the DC/DC comes on? Have you ever received the FP notification of battery drain because that's the only time when unplugged that you'll see it kick on?

Here is what I measured:

1) This is shortly after the HVB target charge was reached (80% SoCD). LVB discharges due to the OBDII scanner. I measured the current draw on the LVB and the car pulls a little over 4 Amps while measuring data using the scanner. That drains the LVB pretty quickly.

2) You can barely see the ripple in the graph, but this is when I unplugged the car. The car continues to maintain the LVB the same way when it is disconnected, starting the charging process when it hits 40% SOC.

3) This is when I plugged the car back in and told it to charge the HVB to 100% SoCD.

I did receive a LVB draining message when I started the car, but I don't think I got one on FP. Probably I should have gotten the message in FP.

I really think if your LVB is not charging when it hits 40% SOC there is a problem.

 

[DevSecOps]

Here is what I measured:

1) This is shortly after the HVB target charge was reached (80% SoCD). LVB discharges due to the OBDII scanner. I measured the current draw on the LVB and the car pulls a little over 4 Amps while measuring data using the scanner. That drains the LVB pretty quickly.

2) You can barely see the ripple in the graph, but this is when I unplugged the car. The car continues to maintain the LVB the same way when it is disconnected, starting the charging process when it hits 40% SOC.

3) This is when I plugged the car back in and told it to charge the HVB to 100% SoCD.

I did receive a LVB draining message when I started the car, but I don't think I got one on FP. Probably I should have gotten the message in FP.

I really think if your LVB is not charging when it hits 40% SOC there is a problem.

I'm not a battery expert ... just not my field. Maybe by the end of my MME ownership I will be.

I should have just kept my mouth shut because I don't have enough data to speak on the subject. I have some rather sophisticated equipment that I've ordered from the Netherlands which will allow me to get much greater insight to all aspects of the car. Once I get that I'll circle back here.

I have theories and I know what the car reports, but other equipment that I use to look at the data, not connected to the OBDII shows different. I'm not sure how the car calculates the SOC and if it's even correct. The car data is wildly inconsistent as shown in the image below where lower voltage is reporting higher SOC.

 

[hawkeye3point1]

I'm not sure how the car calculates the SOC and if it's even correct. The car data is wildly inconsistent as shown in the image below where lower voltage is reporting higher SOC.

Have the same concern with what I have seen reported by Carscanner. Giving the benefit of doubt to the software, I can only attribute it to temp. compensation because the Northeast has gone from Spring to Arctic conditions over the last 3 days.

 

[RWG]

All of this discussion about 12v battery charging issues is making me nervous, even though I have not had that problem, but we have only had our MMe for about 30 days. So, yesterday I ordered a wireless remote DC voltage device so I can see the 12v DC battery voltage on my phone. My plan is to occasionally check the 12v battery voltage and determine the charging activity, in real time.

Does anyone know what the voltage specs would be could be and the patterns for charging so I can maybe better understand what I am seeing? I will probably get the device installed by the weekend and I will certainly share what I discover.

PS: I find it interesting and perhaps disappointing that Ford did not build in any 12v battery charging indicators on the Sync 4. They have plenty of statistical data for the High Voltage Battery but to my knowledge they only 12v battery condition/fault alert comes from Ford Pass, and that app is very unreliable/buggy. If I can independently monitor DC voltage to the 12v battery, perhaps I can avoid an unpleasant episode here in the frozen tundra of Minnesota.

 

[Jiji]

All of this discussion about 12v battery charging issues is making me nervous, even though I have not had that problem, but we have only had our MMe for about 30 days. So, yesterday I ordered a wireless remote DC voltage device so I can see the 12v DC battery voltage on my phone. My plan is to occasionally check the 12v battery voltage and determine the charging activity, in real time.

This thread detour has nothing to do with a LVB battery problem just some observations on how the MME keeps the LVB charged. I wouldn’t worry about it (I certainly don’t) so read this if you think MN nights are a problem.

https://www.macheforum.com/site/thr...-mach-e-range-test-what-could-go-wrong.11669/

 

[mkhuffman]

I'm not a battery expert ... just not my field. Maybe by the end of my MME ownership I will be.

I should have just kept my mouth shut because I don't have enough data to speak on the subject. I have some rather sophisticated equipment that I've ordered from the Netherlands which will allow me to get much greater insight to all aspects of the car. Once I get that I'll circle back here.

I have theories and I know what the car reports, but other equipment that I use to look at the data, not connected to the OBDII shows different. I'm not sure how the car calculates the SOC and if it's even correct. The car data is wildly inconsistent as shown in the image below where lower voltage is reporting higher SOC.

Todd, maybe what is shown in your graph as inconsistency between %SOC and voltage is actually pointing out the %SOC is taking into account other variables besides voltage.

My graph is definitely consistent: the LVB is always charged when it hits 40%. Whatever logic the systems in our car is using to determine the maintenance point, it is definitely following a consistent pattern. In fact, here is the same data I posted above but with the LVB voltage included. It looks pretty consistent to me.

The fact that yours does not charge at 40% is strange, and not what we would expect for good maintenance of the LVB. In fact, 40% may also be too low, but it is certainly better than letting the LVB get down to 15%.

 

[Jiji]

Back on topic, started playing with some visualizations and made a change to the GPS logging.

For those who skipped to the end, the GPS data available on the OBDII port is crippled to the point where is it not useful and to fix this I wrote an iPhone app that would supply navigation-quality GPS data to my application. Well it worked fine in the lab, aka the basement, but in the real world it would timeout to where it was pretty useless.

I decided that I would have my Raspberry Pi talk to the phone using Bluetooth LE and I almost took off in that direction before I had the most wonderful epiphany - just use the local IP address of the phone and move on. On my iPhone using the Personal Hotspot feature, the Raspberry Pi gets the IP address 172.20.10.5 and the iPhone is at 172.20.10.1. So change my server to listen at http://172.20.10.1:8080 and now I get reliable GPS data with just 10-20ms latency. Sorry BLE, you will have to wait for a future project.

So I really wanted to see a graph of elevation vs distance and I find out that Grafana, the visualization software I am using, doesn't have this option but there is a plugin that someone made that I corralled into duty, here is my first result:

What you see is the odometer on the x-axis, which has a resolution of 0.1 km which means I have many more elevation points than odometer points so I have to toss them out. It sort of works but needs some refinement. We can look at the same data using time as the x-axis, here all the elevation samples get to contribute to the graph and I have access to the full graph options that the scatter graph plugin doesn't have.

So there are my first trip data visualizations, more to come as I start working the database and the visualization software. Got to get moving though, 50℉ today and I won't want to be doing this when spring rolls around.

 

[MachTri]

Interesting. Just curious if you are using the GPS Elevation in order to see how altitude or incline and decline effects battery use? Not sure how accurate you need, but GPS altitude data is pretty rough. You might to look into a Digital Elevation Model (DEM) to map the Lat/Lon to elevation on the ground if you want it to be super accurate. I think the USGS has some free ones you can download.
But GPS might be good enough. Also the Location Services in the iPhone might already correct using a DEM and/or altimeter. Just wanted to give you a heads-up incase you get weird data.

 

[Jiji]

Interesting. Just curious if you are using the GPS Elevation in order to see how altitude or incline and decline effects battery use? Not sure how accurate you need, but GPS altitude data is pretty rough. You might to look into a Digital Elevation Model (DEM) to map the Lat/Lon to elevation on the ground if you want it to be super accurate. I think the USGS has some free ones you can download.
But GPS might be good enough. Also the Location Services in the iPhone might already correct using a DEM and/or altimeter. Just wanted to give you a heads-up incase you get weird data.

iPhone seems good (it has an altimeter as you mention) at the few places I know the elevation, I could lookup the elevation using the (lat, long) but either it is slow (USGS) or you pay after a few thousand lookups, and there are a lot of GPS data points in a trip so I'll stick with what I have until I see a problem.

I am just throwing things out there to see what works, using time or distance as an x-axis is just something I decided to play with. I plan to add the HVB power in the graph, should be some correlation with the hills but you never know what surprises are in the data. But I am at the limit of what the Grafana software can do (not setup for geographical data) and I need small maps showing the trip start/end points, overlay the GPS track on a map, etc, and for this I will be looking at something designed to handle geographical data.

But first I need to wrap up the recording functionality before diving into the visualation.

 

[SpaceEVDriver]

Interesting. Just curious if you are using the GPS Elevation in order to see how altitude or incline and decline effects battery use? Not sure how accurate you need, but GPS altitude data is pretty rough. You might to look into a Digital Elevation Model (DEM) to map the Lat/Lon to elevation on the ground if you want it to be super accurate. I think the USGS has some free ones you can download.
But GPS might be good enough.

iPhone seems good (it has an altimeter as you mention) at the few places I know the elevation, I could lookup the elevation using the (lat, long) but either it is slow (USGS) or you pay after a few thousand lookups, and there are a lot of GPS data points in a trip so I'll stick with what I have until I see a problem.

I used to work for the USGS doing some of this kind of software work... And still do some of this work on other planets. Once I get my Mustang, I'm going to try to take your project from github and implement it in my own system. One of the things I wanted to play around with was getting a high-resolution DEM put into a fast database for exactly this kind of purpose. I have experience with Python+geographical data, but not with phone interactions, so maybe I can (eventually) submit some changes later this year.

 

[Jiji]

I used to work for the USGS doing some of this kind of software work... And still do some of this work on other planets. Once I get my Mustang, I'm going to try to take your project from github and implement it in my own system. One of the things I wanted to play around with was getting a high-resolution DEM put into a fast database for exactly this kind of purpose. I have experience with Python+geographical data, but not with phone interactions, so maybe I can (eventually) submit some changes later this year.

You would have two sources of elevation, the MME GPS and the phone GPS but I have low confidence in the Ford nav data. They use Here (https://www.here.com/) and they show my home address out in a field so report an address on another street. I corrected the Here mapping data but when will Ford get around to updating it.

Also DEM seems a waste to me, technically only elevations on a roadway/parking area would needed (unless you plan to off road your MME)and when it comes down to, is there really a need for high-accuracy elevation data for what amounts to a navigation application?

But probably easy enough to take the GPS data from a trip and run it through a DEM lookup, should answer the question of elevation data quality.

 

[SpaceEVDriver]

Also DEM seems a waste to me, technically only elevations on a roadway/parking area would needed (unless you plan to off road your MME)and when it comes down to, is there really a need for high-accuracy elevation data for what amounts to a navigation application?

But probably easy enough to take the GPS data from a trip and run it through a DEM lookup, should answer the question of elevation data quality.

DEM isn't too difficult to manage, and doing some preprocessing with something like openstreetmap would allow the removal of most of the bulk of useless data.

If you just want to check your elevation accuracy, send a few points to the National Map Elevation Point Query Service.

https://nationalmap.gov/epqs/

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