Extracting useful data from your OBDII port

[gwatpe]

As much as I hate mentioning brands, I have just connected my iPad to the car, WiFi OBD2 port. I have used Telnet Lite. This app has a nice feature of macros. I can extract the Ah from the PHEV using 7 stored macros. I no longer need a cheat sheet. According to the car computer, the battery has lost 0.1Ah from the workout last week. The App supports multiple connections, so it should be possible to set up to extract other code combinations for more data.

Not useful for monitoring, but perfectly adequate for occasional checking of the battery health.

BTW Ah will normally be 01 XX The XX will be less than hex 91 . Mine was hex 0x175, so 37.3Ah.

 

[anko]

..., but perfectly adequate for occasional checking of the battery health.

 

[zzcoopej]

I have developed an Android App using the "Anko codes" so we can have a screen on our Android phones to show the internals of the battery pack. So far....

Just a bit of an update, my app is NOT yet in Google Play store. I am almost at Beta test stage having had Anko confirm Wifi dongle support is working. So if you want to participate please email me with a bit of background about yourself (being interested enough in the PHEV to read this post is a good start!).

I now have support for Wifi OBD2 dongles as well as bluetooth.
The App is likely to be called EvBatMon once it gets to Google play hopefully before November.
Like Anko who has put real money as well as time into this project, my costs are ticking up, personally I've spent over $200 to date on this project. I am thinking of putting a small <$10 amount on the Play Store version to share between Anko and I, do you think that is reasonable? There is a $25 fee for Google play store, plus Google take about 40% of the purchase price so between 2 people you don't end up with much!

 

[gwatpe]

Would it be possible to see a few screen shot pics of what we can expect to see on your app.

I am hoping that there will be a few layers of screens, to separate dynamic data like power and torques etc from say battery voltage and battery Ah capacity, service type info etc.

I would consider retro fitting a tablet on a hinge arrangement in front of the MMCS to show streamed live data or a service data, type screen. MMC might get the hint and upgrade the MMCS to include some more useful data screens as well.

 

[zzcoopej]

Would it be possible to see a few screen shot pics of what we can expect to see on your app...I am hoping that there will be a few layers of screens...

I will post some screenshots in a week or so when they are more finished. In the meantime, EvBatMon is completely user configurable similar to other OBD scanner Apps, so you can put whatever PID(Measurement) you want on whatever screen/dashboard you want. You can set it up just how you like it!

 

[Lyra252]

I have developed an Android App using the "Anko codes" so we can have a screen on our Android phones to show the internals of the battery pack. So far....

Just a bit of an update, my app is NOT yet in Google Play store. I am almost at Beta test stage having had Anko confirm Wifi dongle support is working. So if you want to participate please email me with a bit of background about yourself (being interested enough in the PHEV to read this post is a good start!).

I now have support for Wifi OBD2 dongles as well as bluetooth.
The App is likely to be called EvBatMon once it gets to Google play hopefully before November.
Like Anko who has put real money as well as time into this project, my costs are ticking up, personally I've spent over $200 to date on this project. I am thinking of putting a small <$10 amount on the Play Store version to share between Anko and I, do you think that is reasonable? There is a $25 fee for Google play store, plus Google take about 40% of the purchase price so between 2 people you don't end up with much!

Hi

I would be really interested in this, but using Torque Pro on an Android phone I get "EV Service Required" message if I leave the ELM323 dongle in and Torque on, even if the car is switched off. Only removing the dongle and restarting the car sets everything back to normal. Any ideas please??

Cheers

Chris

 

[gwatpe]

I have seen the EV service required screen come up with an OBD2 HUD connected. I believe that there is a poor connector somewhere under the dash of my PHEV, that interrupts the CANbus data flows. I had a similar message when the OBD2 port was wriggled with the car powered ON. On my round Australia travels, I pulled out the OBD2 interface on very bumpy roads, as messages came up quite often. Messages do stick in the PHEV memory, but have no adverse effects on PHEV systems so far. I have not seen any problems with the WiFi type adapter. I assumed it was the pressure of a cord on the adapter hanging off the port causing a problem with wiring under the dash.

Was not a big enough problem as only happened ever now and then and only with something in the port.

 

[gwatpe]

I am just doing a full corded recharge of my PHEV, remaining battery range = 1km, and the OBD2 data has %SOC = 34.5%, battery voltage =307V, total battery capacity = 37.2Ah and remaining battery capacity = 12.8Ah. This gives 24.4Ah to fully recharge. The remaining Ah by calc is equivalent to 34% of the total battery capacity, so matches the PHEV. The 24.4Ah times the approx voltage of 310V gives just over 7.5kWh to be stored.

I will be recording the kWh from the plug to fully recharge, with a kWh meter, and comparing with the estimated 7.5kWh, the battery needs to be fully recharged according to the OBD2 data.

So far at 50% on the battery gauge, OBD2 has %SOC to 64.5% now. 4.45kWh by plug meter and 23.9Ah now in the battery, so 11.1Ah added to the battery at 321V = 3.56kWh.

Up to 75% on the battery gauge. OBD2 has 84%SOC now 7.17kWh by plug meter. 31.3Ah now in the battery, so 18.5Ah added to the battery. Up to 326V now. Approx 6.03kWh.

Fully charged and OBD2 has 98% now. 9.04kWh by plug meter. 36.4Ah in the battery, so 23.6Ah was added. Battery voltage now at 327V. Approx 7.72kWh put back in the battery.

This simple test is showing that a significant amount of extra energy is needed to fully recharge the battery. I was only able to record just over 9kWh from the cord, resulting in close to the full amount of 23.6Ah into the battery. The battery voltage did rise slightly, from 307V to 327V. This is not significant and shows a battery with low impedance. The voltage works out to be 4.09V/cell.

Having this sort of data available in an app would allow this sort of test to be done to routinely check the battery performance over time.

 

[PeterGalbavy]

Another piece of (semi real time) data I would be curious to see is the current flow while driving and regen braking.

I always thought that the console Engine / Wheel / Battery diagram should have either a varying line thickness or a numeric overlay of kW being moved around...

 

[anko]

Gwatpe,

12.8 Ah * 307 volt = 3.93 kWh
36,4 Ah * 327 volt = 11.90 kWh

Difference is almost 8 kWh. Compared to the 7.72 kWh you came up not a huge difference, but looking at the loss (1,07 versus 1,32 kWh, so approx. 25% less), I would call it significant.

 

[anko]

Another piece of (semi real time) data I would be curious to see is the current flow while driving and regen braking.

I always thought that the console Engine / Wheel / Battery diagram should have either a varying line thickness or a numeric overlay of kW being moved around...

It does not tell you whether the engine runs. It tells you whether the engine is driving the wheels. The engine can run, even in parallel mode, without driving (putting force to) the wheels and yet consume fuel.
Similar, energy can flow from the battery tho the E-motors and even the generator (in parallel mode) while the dash shows no energy flow whatsoever.

 

[gwatpe]

Gwatpe,

12.8 Ah * 307 volt = 3.93 kWh
36,4 Ah * 327 volt = 11.90 kWh

Difference is almost 8 kWh. Compared to the 7.72 kWh you came up not a huge difference, but looking at the loss (1,07 versus 1,32 kWh, so approx. 25% less), I would call it significant.

There is a problem with batteries and energy contained in them. The battery voltage decreases with energy drawn out. The max energy contained in the battery is not just the Ah x the max voltage. Better to say use half the difference in voltages, say 317V, so 11.5kWh minus 3.9kWh = 7.6kWh, that needed 9.04kWh to be replaced to fill the battery back up to full.

My PHEV has about 7.7kWh of stored energy available before series hybrid mode operates. It needs 9kWh to fill the gauge back up to full. I am still working out why the battery recharging is appearing to be so poor.

Maybe there are some really lossy rectifier diodes, or a DC-DC boost converter to bring the RMS voltage up from 240 to 320V.

 

[smbunn]

I think paying $10 for the app makes perfect sense, happy to be a beta tester too if required.
I also agree that while real time data display is great, benefits are best achieved form extracting the data from a SQL database at the end of the trip.

 

[gwatpe]

I would expect that the population skilled at SQL, or any other database manipulation tool would be far smaller than even the one that could successfully use the app on a phone. I do however know the benefits of examining recorded data later.

Here is a pic of some data that I collect at my house, from my CC128Professor windows app.

RAW data display

and a graph of some data last week.

I have designed an interactive calendar to rapidly find predefined types of data, without having to open and extract entire days of data. Sort of like a browser, but not like a thumbnail.

I have many GB of data collected over 10 or so years, including weather station data.

Adding PHEV data to the mix will more complete my energy usage footprint, as well as aiding in better knowing how the PHEV works.

 

[zzcoopej]

I also agree that while real time data display is great, benefits are best achieved form extracting the data from a SQL database at the end of the trip.

I am currently adding SqlLite data logging support in EvBatMon, as well as CSV output. I also plan in the future to add the ability to upload data directly from EvBatMon to my website for easier manipulation and analysis for users who aren't technically minded. "It won't happen overnight, but it will happen...."

 

[t3lmo]

I'm really curious about this development! Reverse engineering is awsome

Others are doing the same for other new BEV...
https://www.facebook.com/photo.php?fbid=10101476745467300&set=gm.904594326287848&type=3&theater

I already have a ELM32 BT OBD, hope it can work well to connect and read the PID's, if not just point us a proper one, Wifi or BT.
Keep us posted!

 

[jthspace]

This seems to be a unit that decodes and displays OBDII information as a heads-up display. Looks interesting, but is it worth the money or just a "gadget" . . . ?

5.5" Head-Up Display Windshield Projector - Black

http://www.dx.com/p/5-5-head-up-display-windshield-projector-black-386225#.VhAuohNViko

 

[gwatpe]

I have 3 of these OBD HUD units. All are a bit different in operation. My first unit operated when the car was powered ON, and even without the ICE operating. Most power down when the ICE is not operating. I had to dim the display on all my units, as they were far too bright at night. The most useful one, I had displays rpm in a dial, L/100km in a small digital display and speed or coolant temp or AUX battery V on a bigger digital display. Was useful as a spot check tool, but I had to run a wire to a manual power ON button switch, as the unit to be useful was not reachable to the driver, in a position that the HUD could project onto the windscreen out of the main drivers view. I also found that with a unit plugged in all the time to the OBD port, that error messages occasionally were reported. Mainly on rough roads, so a possible connector issue in the wiring.

A wireless system with a tablet, for monitoring/logging data is going to be a great improvement.

 

[zzcoopej]

Update - there has been good progress with the Android App EvBatMon for our PHEV cars.
Here are a couple of pictures.
Anyone with a OBD Dongle that isn't on the Beta list yet, please message me with your email address.

Battery and real time PID display -

Cell voltages -

 

[t3lmo]

Beta list yet, please message me with your email address.

Can I apply for beta tester also? If help needed, I'm a software engineer also.