Chevy Bolt EV Forum banner

41 - 60 of 86 Posts

·
Registered
Joined
·
6,259 Posts
There are two numbers I am interested in from these diagnostic ports. What is the pack voltage when the car says you are at the 90% "hilltop", and 100% charge? The Bolt, like most OEM cars, has 96 cells (actually parallel cell groups) in series. The full voltage range of current lithium-ion cells is 3.0 volts to 4.2 volts, so 96 x 4.2 = 403.2 volts. I assume all OEMs avoid going to 4.2 volts.

Here is the Chevy Volt LG pack info from a government lab test:

https://avt.inl.gov/sites/default/files/pdf/phev/batteryVolt4313.pdf

LG is choosing 4.15 volts for their upper limit, 96 x 4.15 volts is 398.4 volts

Conversely, what does the port voltage read when the car says it is empty? How close is it to 288 volts? Theses numbers will tell us how big the pack is, and how much GM/LG are allowing us to access.
 

·
Registered
Joined
·
1,003 Posts
My current car, which is a plug in hybrid, has the same 'issues'. I can identify 7 different busses, 3 of which are high-speed 500 kbps busses. But they are all connected through gateways. The gateways let some traffic pass and some other not, in order to keep the amount of traffic on each bus within limits.

Normal question / response ODBC requests are always let through by the gateways, so I can access each ECU via the main DLC port. But when I want to monitor traffic that is broadcasted by various ECUs I typically only see the data from the ECUs that are on the same bus as the DLC port (which happens to be the bus that controls most ECUs common to petrol cars). In order to be able to capture data broadcasted by the ECUs of the E-motors, the generator, the OBC, BMU, etc., I had to install a second DLC port on one of the other high speed busses. And that works just fine, using the same type of OBDC adapters.

Where I got confused is where you said both ports have the same power supply, yet one is specifically for a 14 volt module. Also, I thought it was a bit odd that on one hand you recommended not to plug in a standard OBDII adapter into the second port, while on the other hand you think it is a good idea that both ports used the same form factor.

From what I understand now, the second DLC port is a 'normal' DLC port where some of the free pins are used to support a very specific device. Does that make sense?

Would this device perhaps allow you to operate the 12 v DC BECM and recharge the battery even after the 12 volt battery is completely flat? Because IMHO that might explain why you want to have the 12 v DC BECM on a separate network.
No. It's for communication and not charging. If the 12 volt battery is dead, so are all the communication buses. Nothing works without 12 volt power. You would need to open the
engine hood and hook up a 12 volt charger to charge the 12 volt system if the HVB wasn't able to be used to charge it through the BECM due to lack power from the 12 volt battery.
 

·
Registered
Joined
·
756 Posts
What is the best Android app to use with a OBD plug?
I have one that I got for my i-MiEV but the app I was using is not great. And the app that came with the OBD doesn't do EV's
 

·
Registered
Joined
·
20 Posts
Full disclosure - this is pure speculation about the passenger side comm port:

Is it possible this OBD port is used by GM to access the power line communications systems with proprietary scan tools so that they can analyze any problems with the CCS port/other PLC derived functions?

Has anyone found actual descriptions/schemas of the PLC/CCS systems being used by the Bolt? And how it might interface with the "traditional" OBDII CAN bus?

Again - pure speculation on my part.
 

·
Registered
Joined
·
115 Posts
I'm using the the LE Link low-energy Bluetooth reader with EngineLink software for iOS. Available from amazon.com:

https://www.amazon.com/dp/B00QJRYMFC

This reader can also be used on Android devices with the Torque Pro app.

The Volt PIDs can be used as a starting point to start reading data. Obviously not all of the Volt PIDs will give you any useful data.
Ended up buying this to use EngineLink. I didn't realize that it comes with a list of Volt PIDs already. That makes it really convenient to get started with it versus having to Google for the codes.
 

·
Registered
Joined
·
115 Posts
Also, on a related note, are the AC charger voltages from the ODB2 accurate? My Bolt says that it's seeing 208V on my home EVSE, but that would be unusual for residential service and I can't think of a reason why there would be a 32V drop otherwise.
 

·
Premium Member
Joined
·
787 Posts
Also, on a related note, are the AC charger voltages from the ODB2 accurate? My Bolt says that it's seeing 208V on my home EVSE, but that would be unusual for residential service and I can't think of a reason why there would be a 32V drop otherwise.
They are accurate for me. If you can, check things with a voltmeter.
 

·
Registered
Joined
·
739 Posts
I'm using the the LE Link low-energy Bluetooth reader with EngineLink software for iOS. The Volt PIDs can be used as a starting point to start reading data.
Do you have any more experience to share with us? I just bought the device. What can you monitor? What are the most useful data you have extracted? Do you use it all the time, or just when you want check to something?
 

·
Premium Member
Joined
·
787 Posts
Do you have any more experience to share with us? I just bought the device. What can you monitor? What are the most useful data you have extracted? Do you use it all the time, or just when you want check to something?
You can monitor just about anything you have a PID for. I’m using the Volt’s PIDs that came preloaded with EngineLink. Some of those PIDs aren’t relevant to the Bolt, like engine RPM, amount of fuel being used, cylinder misfires, etc. But a lot of them are useful, like battery voltage, how much current the EVSE is supplying, SOC (state of charge), etc.

I’ve attached a couple of examples of charging, one using a DC fast charger, and the other showing what my EVSE at home can supply.
 

Attachments

·
Registered
Joined
·
739 Posts
I’ve attached a couple of examples of charging, one using a DC fast charger, and the other showing what my EVSE at home can supply.
Is the information instantaneous, or is historical data saved in the app? Thanks for your input on this.
 

·
Premium Member
Joined
·
787 Posts
Is the information instantaneous, or is historical data saved in the app? Thanks for your input on this.
Instantaneous, at least for EngineLink on iOS. Torque Pro on Android may have logging abilities, but I haven't used that app, so I don't know for sure.
 

·
Registered
Joined
·
1,003 Posts
There are two numbers I am interested in from these diagnostic ports. What is the pack voltage when the car says you are at the 90% "hilltop", and 100% charge? The Bolt, like most OEM cars, has 96 cells (actually parallel cell groups) in series. The full voltage range of current lithium-ion cells is 3.0 volts to 4.2 volts, so 96 x 4.2 = 403.2 volts. I assume all OEMs avoid going to 4.2 volts.

Here is the Chevy Volt LG pack info from a government lab test:

https://avt.inl.gov/sites/default/files/pdf/phev/batteryVolt4313.pdf

LG is choosing 4.15 volts for their upper limit, 96 x 4.15 volts is 398.4 volts

Conversely, what does the port voltage read when the car says it is empty? How close is it to 288 volts? Theses numbers will tell us how big the pack is, and how much GM/LG are allowing us to access.
Here's some data from my car @ 82% charged. I use HTR and it's been driven today for a few miles.
I don't know how many, but, I would say at least 10 to 15 miles.
I like how battery pack size is a code :eek:
 

Attachments

·
Registered
Joined
·
5,084 Posts
I like how battery pack size is a code :eek:
"06E7" looks suspiciously like exponential notation to me - it's the sort of thing you see in unformatted computer output of floating point numbers. It would mean "6 x 10^7", or 60,000,000. Seems a bit too coincidental that it happens to match the 60kWh pack size as expressed in milliwatt-hours.
 

·
Registered
Joined
·
4,051 Posts
"06E7" looks suspiciously like exponential notation to me - it's the sort of thing you see in unformatted computer output of floating point numbers. It would mean "6 x 10^7", or 60,000,000. Seems a bit too coincidental that it happens to match the 60kWh pack size as expressed in milliwatt-hours.
Dang, if we could get 06E9 than we could start doing some time travel.
 

·
Registered
Joined
·
739 Posts
I’ve attached a couple of examples of charging, one using a DC fast charger, and the other showing what my EVSE at home can supply.
I now have the adapter in hand, and the software working, so now I can gain experience. Thanks for uploading the images. They were very helpful. It took me a few minutes to find the Volt PIDs, but I arrived there eventually! The instructions are none-existent so you have to poke around to find things.
 

·
Registered
Joined
·
115 Posts
They are accurate for me. If you can, check things with a voltmeter.
Turns out that my townhouse has commercial type three-phase service with only two phases run to my box. Since it's 120º out of phase instead of 180º out of phase, I only get 208V. Kind of a bummer, but nice when the power goes out because we don't usually lose all phases.
 

·
Registered
Joined
·
739 Posts
LElink data

I'm using the the LE Link low-energy Bluetooth reader with EngineLink software for iOS. The Volt PIDs can be used as a starting point to start reading data. Obviously not all of the Volt PIDs will give you any useful data.
Following on devbolt's work with LELink I am starting to obtain interesting if not necessarily useful information. I have found for example, that since the cold weather started, the car is conditioning the HV battery near the end of the charging cycle. For example, after a day of driving in cold weather just above freezing, I charge the car in my garage. While charging, the battery warms up a bit from say 12 C to 14 C, but near the end of the charging cycle about 0.8 kWh of energy is used by the car to heat up the battery to 15C, which is about the ambient temperature of my garage. This is one factor that contributes to what some call "charging losses". I do not have sufficient data yet to characterize this, but its starting to look interesting.
 
41 - 60 of 86 Posts
Top