Performing a DBCAM (battery calibration) using a ThinkCar OBD scanner, with screenshots (for PHEV up to 2022)

[ASeitzinger]

What are the absolute numbers you got? The SOH is an estimate and can also err on the high side.
Did you reset the data prior to dbcam?

 

[fmus]

What are the absolute numbers you got? The SOH is an estimate and can also err on the high side.
Did you reset the data prior to dbcam?

Reset done before dbcam.
Was showing 38Ah after reset

 

[Daixiwen]

Afternoon, I completed the dbcam as per.the instructions above with the thinkdiag odb. All seems to have gone well until after I had recharged the battery. The charging process went well and finished as normal.
My driving range was reduced to below pre dbcam.
I took the car for a drive anticipating to get new recalculated values with higher driving range.
Unfortunately no improvement in range and.the battery capacity after dbcam was accurate.
What I don't understand is is why it's lower than before dbcam.
I also carried cell smoothing successfully.
Any ideas?

Which range reduced after the charge? The actual range you can drive until the ICE engine starts, or the range shown on the guess-o-meter?
Can you check what the battery state of charge is right before the ICE starts?

 

[fmus]

Which range reduced after the charge? The actual range you can drive until the ICE engine starts, or the range shown on the guess-o-meter?
Can you check what the battery state of charge is right before the ICE starts?

Hi Diaxiwen
I repeated the dbcam yesterday, in case I had messed up something the first time.
I will report back to this is complete.

 

[fmus]

Hi Diaxiwen
I repeated the dbcam yesterday, in case I had messed up something the first time.
I will report back to this is complete.

I completed the dbcam as per the instructions below successfully, however my range had gone down to 12km, with battery capacity of 12Ah.
Previous to this could cover 16 km. i also noticed that when looking at the individual cell numbers, there are some numbers missing. Not sure if these are dead cells or if this is normal numbering of the cells.
The regen braking is also not as powerful as it used to be, it feels like the car is stuttering when it is engaged. anyway that being said it may be a sigh for me to sell the car.

 

[ASeitzinger]

I think you should look for a new battery or - depending on your possibilities - replace the cells. 12Ah is dead

 

[Daixiwen]

Yes 12Ah sounds like it's very low. Are you able to get the individual cell voltages? I don't remember if it can be done from the Thinkdiag tool, but at least Phev Watchdog can do that. If you have one or several cells that is at a voltage that is significantly higher or lower than the other ones in the battery it will disturb the battery capacity measurement process. You can attempt to realign the cell voltages by using the cell smoothing procedure but if the different is too important it won't fix the problem.

 

[fmus]

Yes 12Ah sounds like it's very low. Are you able to get the individual cell voltages? I don't remember if it can be done from the Thinkdiag tool, but at least Phev Watchdog can do that. If you have one or several cells that is at a voltage that is significantly higher or lower than the other ones in the battery it will disturb the battery capacity measurement process. You can attempt to realign the cell voltages by using the cell smoothing procedure but if the different is too important it won't fix the problem.

The thinkdiag app is able to read individual cell voltages. They all seem to be within +/- 0.01-0.02v.
The only thing noticed was the cell numbers seem to be like 1-50 then 59-74 then 83 to the last. I am not sure why there are gaps, missing numbers orig that is the correct number process used by mitsubishi. Are you able to check yours with the thinkdiag?
Finally I read the mitsubishi bulletin on replacing individual cells, the cell voltage differences are critical and balancing is not guaranteed to work. Almost need to replace the entire pack

 

[fmus]

Which range reduced after the charge? The actual range you can drive until the ICE engine starts, or the range shown on the guess-o-meter?
Can you check what the battery state of charge is right before the ICE starts?

The range to when the engine kicks in, this happens when the battery SOC is about 8.9AH

 

[Daixiwen]

The thinkdiag app is able to read individual cell voltages. They all seem to be within +/- 0.01-0.02v.
The only thing noticed was the cell numbers seem to be like 1-50 then 59-74 then 83 to the last. I am not sure why there are gaps, missing numbers orig that is the correct number process used by mitsubishi. Are you able to check yours with the thinkdiag?
Finally I read the mitsubishi bulletin on replacing individual cells, the cell voltage differences are critical and balancing is not guaranteed to work. Almost need to replace the entire pack

Sorry for the delay. I checked and I have gaps too. I guess it is just the way Mitsubishi enumerates the cells, perhaps to match how they are placed in the battery. If I count all the cells I do have 80 of them, with numbers from 0 to 127 and with several gaps.

 

[Daixiwen]

I made a few more experiments... first you do need to put the car in ready mode to perform the DBCAM. If you are just in ACC mode the procedure won't start.
Second I tried the "Write Learned Value(Changed ECU)" function to write back the battery age after a reset. When you select this function, you have 3 choices:

• Learned Value Read&Save
• Saved Learned Value Writing
• Manual Writing

I thought that what you were supposed to do is to choose "Learned Value Read&Save" before the reset, and then choose "Saved Learned Value Writing" after a reset to put the values back. I tried that but it completely botched the DBCAM procedure. Just after I used "Saved Learned Value Writing" it changed the battery capacity to 8 Ah, and it never went up again. It looks like there is something wrong with that function, and it overwrites more than just the battery age.

I'll try again a DBCAM soon with a manual writing of the values instead, it looks like it doesn't have the same bug. As other said in this thread there is an error in the UI, when they ask for the batteri mileage, it is in fact the total Ah charged and discharged.

 

[Daixiwen]

I completed the dbcam as per the instructions below successfully, however my range had gone down to 12km, with battery capacity of 12Ah.
Previous to this could cover 16 km. i also noticed that when looking at the individual cell numbers, there are some numbers missing. Not sure if these are dead cells or if this is normal numbering of the cells.
The regen braking is also not as powerful as it used to be, it feels like the car is stuttering when it is engaged. anyway that being said it may be a sigh for me to sell the car.

Did you use the "Write earned Value(Changed ECU)" function, and especially the "Saved Learned Value Writing" option? If yes I would suggest to do a new BMU reset and DBCAM, but without the "Saved Learned Value Writing" option. In my case it reduced the measured battery capacity from 28 Ah down to 8 Ah....

 

[fmus]

Did you use the "Write earned Value(Changed ECU)" function, and especially the "Saved Learned Value Writing" option? If yes I would suggest to do a new BMU reset and DBCAM, but without the "Saved Learned Value Writing" option. In my case it reduced the measured battery capacity from 28 Ah down to 8 Ah....

I haven't done anything to do with Learned Value. I didn't understand why it needed to be done so I haven't gone that far.
1. What is the benefit for changing the Learned Value?
2. If it's not changed what is the disadvantage,?

 

[Daixiwen]

The benefit is that the BMU has the correct battery age, but I don't know if it changes anything about how the BMU operates. I have driven my car a couple of months with the wrong data, and will now drive it a bit with the correct one and I'll report here if I notice any difference.

But anyway, I wonder if something wrong happened when you did your DBCAM too and it may be worth it to try it again.

 

[fmus]

The benefit is that the BMU has the correct battery age, but I don't know if it changes anything about how the BMU operates. I have driven my car a couple of months with the wrong data, and will now drive it a bit with the correct one and I'll report here if I notice any difference.

But anyway, I wonder if something wrong happened when you did your DBCAM too and it may be worth it to try it again.

That makes senses, I will redo the procedure and write the battery age. At the moment I am, deciding between swapping out the individual cells, or buying a used battery pack, or selling the car. All these options are fraught with complications. Just seeing which one will be the least difficult for me.

 

[Woon Chung]

That makes senses, I will redo the procedure and write the battery age. At the moment I am, deciding between swapping out the individual cells, or buying a used battery pack, or selling the car. All these options are fraught with complications. Just seeing which one will be the least difficult for me.

There are many people in this forum with different levels of knowledge on a certain field of a car. As for me, I have basic knowledge and tools on car mechanisms, so that I used to maintain disposable parts by myself except engine and transmission. Because those field requires more than regular tech and knowledge and tools. If we can't reach to the end of total process by myself, we have to quit in the middle of process by short of other people's help.

Battery pack tech is one of uncomplicated field and there are not so many people who is capable to finalize each individual case. Even Service center officially cannot control the battery issues, because of the lack of diagnostic tech, perfectly.

I believe that someone has excellent skills on using test equipment, and building up his knowledge level to become a specialist on such a field but, do not expect him to solve all troubles you have. Sometimes, it's better not to try to solve the problem by yourself if it is involved with most advanced modern scientific technology. It's too far away from regular people's reaching.

Under this kind of concept, try to find battery specialist, and being diligent to find good guy, or, if it is not possible, just drive and enjoy it. It might not the real default of the battery. Or, still you feel uncomfortable with EV distance, swap it with other car which has more modern technology than Mitsubishi, which is still hanging in old battery tech.

Good luck to you