Evbatmon and Phev watchdog is showing the wrong SOH amount.

[Trex]

Now as the title says Evbatmon and Phev watchdog is showing the wrong SOH amount. Now that is IMHO. Why do I think this? Well lets get some history on how they are working it out first.

I will bring in a quote from anko from another thread that I started:

The capacity % is calculated by comparing Current Capacity Ah with Current Capacity when new. As this number is not known, Daniel Santos (WatchDog) uses 38 as a baseline value. I can only guess Jeremy does the same.

Now as anko states both are using 38 Ah as a baseline for measuring because in that thread I had current capacity of 29.9 Ah divided by 38 Ah gives approx 78.68% SOH and Evbatmon was showing 78.68% and Phev watchdog was showing 78.7% at the time.

Now Mitsubishi have stated we have a 40 Ah cell capacity so I not sure why this 38 Ah is used as a baseline or anko states that this number is not known unless it is because that is mainly what they read on the OBD device when a new PHEV gets to a customer. Hell I have even seen people write that the difference between the two values is the top side buffer ie the amount not used to reduce degradation of the drive battery. Even a value for this top side buffer has been placed as 5%. I think they work this out by 38 Ah divided by 40 Ah gives 95% subtract from 100% gives that 5%.

So lets see some examples of where Mitsubishi have stated we have a 40 Ah battery capacity:

Phev high voltage battery opened,



12 kwh 40 amp/hour and 184kg weight.

MMC via anko.

This one from MMC.



Regards Trex.

Now you can see in both these images we have a 40 Ah battery ie 12 kWh or 12,000 watts divided by 300 volts nominal gives 40 Ah as well as being called a LEV 40.

Now as another example of our battery being 40 Ah and not 38 Ah, on my battery report from the MUT-III after a drive battery recalibration (auto capacity measured procedure)
BMU data list number 18 gives me the Battery current capacity of 28.3 Ah (BTW up from 26.8 Ah ) and the BMU data list number 401 Cell current capacity difference of 11.7 Ah. Add those two ie 28.3 plus 11.7 gives 40 Ah.

Now back to my previous example above where I had a current capacity of 29.9 Ah Evbatmon and Phev watchdog should be showing 74.75% SOH (29.9/40) and not 78.68% (29.9/38) IMHO.

Also about that top side buffer I was writing about previously, this should be above that 40 Ah capacity and NOT shown as part of that 40 Ah capacity because we can never use it at the moment unlike the bottom side buffer ie below approx 26-30% SOC that can be accessed in some special circumstances.

Now I wanted to bring this up as there is so much misrepresentation IMHO about this out there I think it needs mentioning. Hell, I think, Mitsubishi have been trying to tell us the truth for years.

Regards Trex.

 

[anko]

When you have a new pre-2019 car delivered to you, SoH reported by the BMU is approx. 38Ah, not 40. To me that is 100% SoH. Otherwise health would be down 5% already upon delivery.

 

[HHL]

Now as the title says Evbatmon and Phev watchdog is showing the wrong SOH amount. Now that is IMHO. Why do I think this? Well lets get some history on how they are working it out first.

I will bring in a quote from anko from another thread that I started:

The capacity % is calculated by comparing Current Capacity Ah with Current Capacity when new. As this number is not known, Daniel Santos (WatchDog) uses 38 as a baseline value. I can only guess Jeremy does the same.

Now as anko states both are using 38 Ah as a baseline for measuring because in that thread I had current capacity of 29.9 Ah divided by 38 Ah gives approx 78.68% SOH and Evbatmon was showing 78.68% and Phev watchdog was showing 78.7% at the time.

Now Mitsubishi have stated we have a 40 Ah cell capacity so I not sure why this 38 Ah is used as a baseline or anko states that this number is not known unless it is because that is mainly what they read on the OBD device when a new PHEV gets to a customer. Hell I have even seen people write that the difference between the two values is the top side buffer ie the amount not used to reduce degradation of the drive battery. Even a value for this top side buffer has been placed as 5%. I think they work this out by 38 Ah divided by 40 Ah gives 95% subtract from 100% gives that 5%.

So lets see some examples of where Mitsubishi have stated we have a 40 Ah battery capacity:

Phev high voltage battery opened,



12 kwh 40 amp/hour and 184kg weight.

MMC via anko.

This one from MMC.



Regards Trex.

Now you can see in both these images we have a 40 Ah battery ie 12 kWh or 12,000 watts divided by 300 volts nominal gives 40 Ah as well as being called a LEV 40.

Just out of interest when the battery is fully charged and when new it is actually approx 13 kWh ie 4.1 V x 80 cells in series gives 328 V x 40 Ah gives 13,120 watts or 13.12 kWh.

Now as another example of our battery being 40 Ah and not 38 Ah, on my battery report from the MUT-III after a drive battery recalibration (auto capacity measured procedure)
BMU data list number 18 gives me the Battery current capacity of 28.3 Ah (BTW up from 26.8 Ah ) and the BMU data list number 401 Cell current capacity difference of 11.7 Ah. Add those two ie 28.3 plus 11.7 gives 40 Ah.

Now back to my previous example above where I had a current capacity of 29.9 Ah Evbatmon and Phev watchdog should be showing 74.75% SOH (29.9/40) and not 78.68% (29.9/38) IMHO.





Regards Trex.

You can't just multiply the peak voltage with Ah, as it goes down (initially quite rapidly) as the battery discharges. That's why battery capacity is now more commonly stated in Wh (or kWh). The fact that it peaks at 4.1V/cell is not relevant, as it doesn't stay there for very long when you start discharging. Also, the cells will have a "nominal" 40Ah rating, perhaps when they are charged to a higher voltage (4.2V?), or discharged to a lower voltage than what actually happens in the PHEV. Mitsubishi can of course still call it a 12kWh battery, but that doesn't mean that capacity is available the way the car is designed to use it.

 

[Trex]

You can't just multiply the peak voltage with Ah, as it goes down (initially quite rapidly) as the battery discharges. That's why battery capacity is now more commonly stated in Wh (or kWh). The fact that it peaks at 4.1V/cell is not relevant, as it doesn't stay there for very long when you start discharging. Also, the cells will have a "nominal" 40Ah rating, perhaps when they are charged to a higher voltage (4.2V?), or discharged to a lower voltage than what actually happens in the PHEV. Mitsubishi can of course still call it a 12kWh battery, but that doesn't mean that capacity is available the way the car is designed to use it.

Ok HHL, I reckon I can get at least 13.12 kWh out of a new PHEV battery but I will let you work out how I will do it and I will not charged it above 4.1 V per cell.

 

[Trex]

You can't just multiply the peak voltage with Ah, as it goes down (initially quite rapidly) as the battery discharges. That's why battery capacity is now more commonly stated in Wh (or kWh). The fact that it peaks at 4.1V/cell is not relevant, as it doesn't stay there for very long when you start discharging. Also, the cells will have a "nominal" 40Ah rating, perhaps when they are charged to a higher voltage (4.2V?), or discharged to a lower voltage than what actually happens in the PHEV. Mitsubishi can of course still call it a 12kWh battery, but that doesn't mean that capacity is available the way the car is designed to use it.

Ok HHL, I reckon I can get at least 13.12 kWh out of a new PHEV battery but I will let you work out how I will do it and I will not charged it above 4.1 V per cell.

Now I will remove that section from my first post above about the 13.12 kWh because I do not want the thread to get waylaid from the main point I was trying to make that we have a 40 Ah rated battery and I was falling into the trap myself of not using Mitsubishi's rated capacities which is what the thread is about. It is NOT a 38 Ah rated battery but according to Mitsubishi a 40 Ah rated battery that gives us 12 kWh of total energy at the nominal voltage of 300 V.

But in most normal circumstances they will ONLY let us use approx 70-74% of that rated 12 kWh because of the bottom side buffer. The top side buffer which we cannot use should never be included in that measurement IMHO and it appears when Mitsubishi measures the true capacity of the the drive battery (Edit. by emptying that bottom side buffer) using the MUT-III they are not including it as well from what I can see ie they are only charging it to approx 4.1 V and they are then comparing the measured result with a 40 Ah rated battery.

 

[Trex]

You can't just multiply the peak voltage with Ah, as it goes down (initially quite rapidly) as the battery discharges....................The fact that it peaks at 4.1V/cell is not relevant, as it doesn't stay there for very long when you start discharging.

Now I will say something about these statements HHL. The amount of decrease in voltage in batteries is dependant on the amount of load placed on the battery I am pretty sure you will find ie it will not go down rapidly if a "light" enough load is applied.

 

[Trex]

When you have a new pre-2019 car delivered to you, SoH reported by the BMU is approx. 38Ah, not 40. To me that is 100% SoH. Otherwise health would be down 5% already upon delivery.

Anko, so because you, and I think probably Jeremy and Daniel who make the apps, believe that 38 Ah is 100 % SOH and not what Mitsubishi state we should use ie 40 Ah, to me that sounds presumptuous of you three to start your own definition of how the SOH should be measured IMHO.

This is starting to sound like ,from memory, maby writing a planetary gearbox is not a gearbox or series mode is a CVT transmission IMHO. Hell, lets all just start making up our own rules and definitions. Should be fun I think. :lol: I will definitely be voting for calling series mode cereal mode. :lol:

Just because the BMU "estimates" (and I think quite badly in some circumstances) the capacity of approx 38 Ah at that point in time when the customer gets his PHEV which could be some time after the PHEV was built and delivered from over the seas and oceans some people should be inventing a new SOH formula.:roll: Sorry anko, but I totally disagree with that sentiment.

 

[zzcoopej]

Anko, so because you, and I think probably Jeremy and Daniel who make the apps, believe that 38 Ah is 100 % SOH and not what Mitsubishi state we should use ie 40 Ah, to me that sounds presumptuous of you three to start your own definition of how the SOH should be measured IMHO.

Trex, while I get what you are saying (and agree with the pedantic semantics), you really should not paint us all with the same brush. In EvBatMon from the beginning I specifically used the label "PMC" which I coined myself as "Percentage of Manufactured Capacity", and not SOH, as I did not believe I was calculating a true SOH value. I actually meant it to be a real-world rather than nominal value, ie "how much has the battery deteriorated since I've owned it", which is very lenient on Mitsubishi (best case).
The current Ah capacity is the real value, so feel free to use 40Ah and you have your SOH and eat it too. Sweet!

 

[Trex]

Anko, so because you, and I think probably Jeremy and Daniel who make the apps, believe that 38 Ah is 100 % SOH and not what Mitsubishi state we should use ie 40 Ah, to me that sounds presumptuous of you three to start your own definition of how the SOH should be measured IMHO.

Trex, while I get what you are saying (and agree with the pedantic semantics), you really should not paint us all with the same brush. In EvBatMon from the beginning I specifically used the label "PMC" which I coined myself as "Percentage of Manufactured Capacity", and not SOH, as I did not believe I was calculating a true SOH value. I actually meant it to be a real-world rather than nominal value, ie "how much has the battery deteriorated since I've owned it", which is very lenient on Mitsubishi (best case).
The current Ah capacity is the real value, so feel free to use 40Ah and you have your SOH and eat it too. Sweet!

Gday zzcoopej or Jeremy,

How the bloody hell are you? Long time no "see". Still work on the app sometimes?

Ok, point taken about the "PMC" which I coined myself as "Percentage of Manufactured Capacity", but now you can fix it to be the proper BMU "estimated" SOH amount as people are using that P.M.C. as such and use 40 Ah as specified by Mitsubishi IMHO.

Now as for "The current Ah capacity is the real value," I would disagree unless it's read reasonable soon after a BMU recalibration but I think I know what you mean.

Pedantic semantics, Ok I am not sure I would have used that term. I would call it trying to get to the bottom of all the misrepresentations I see about this topic.

Regards Trex.

 

[Darkflow]

Further on this, reports are that the BMU shows 40 Ah when the capacity measurement procedure is carried out on the new batteries that are being installed in some Australian cars.

It seems as though the 38 Ah is some sort of default setting in the BMU.

 

[Trex]

Further on this, reports are that the BMU shows 40 Ah when the capacity measurement procedure is carried out on the new batteries that are being installed in some Australian cars.

It seems as though the 38 Ah is some sort of default setting in the BMU.

Yes IMHO this "out of whack" BMU has been causing problems for a while. I hope Mitsi sort it out with a BMU update over here and elsewhere one day.

But a 40 Ah rated battery is what Mitsubishi has been telling us for years is in the PHEV and we have apps using 38 Ah as the "baseline". Not good IMHO because we are speaking different amounts of degradation or SOH in % terms compared to Mitsubishi. :roll:

At least we now know that the apps are wrong and can work around their faults IMO. Or they can fix the apps I suppose. Although the degradation or SOH in % terms will be showing worse than before but I can handle that.

 

[anko]

In EvBatMon from the beginning I specifically used the label "PMC" which I coined myself as "Percentage of Manufactured Capacity", and not SOH, as I did not believe I was calculating a true SOH value.!

And I think this number is what 95% of the people are interested in.

And I wonder: If PMC has gone down by 10%, can we not assume that SoH has gone down with roughly that same 10%?

Altogether, we know initial available capacity (38 Ah) and we have a notion of current available capacity. As we have no notion of current gross capacity, how is it going to help us if we know initial gross capacity?

 

[Trex]

Anko, so because you, and I think probably Jeremy and Daniel who make the apps, believe that 38 Ah is 100 % SOH and not what Mitsubishi state we should use ie 40 Ah, to me that sounds presumptuous of you three to start your own definition of how the SOH should be measured IMHO.

Trex, while I get what you are saying (and agree with the pedantic semantics), you really should not paint us all with the same brush. In EvBatMon from the beginning I specifically used the label "PMC" which I coined myself as "Percentage of Manufactured Capacity", and not SOH, as I did not believe I was calculating a true SOH value. I actually meant it to be a real-world rather than nominal value, ie "how much has the battery deteriorated since I've owned it", which is very lenient on Mitsubishi (best case).
The current Ah capacity is the real value, so feel free to use 40Ah and you have your SOH and eat it too. Sweet!

After thinking a little more about what Jeremy wrote here:

...........you really should not paint us all with the same brush.

This to me is now starting to sound like a "cop out" or running away from his responsibility for helping create the problem IMO. He invents a label called PMC which stands for Percentage of Manufactured Capacity. Lets just look at that Percentage of Manufactured Capacity wording. To me it looks like he is writing about Mitsubishi's (or GS Yuasa's) Manufactured Capacity. Well Mitsubishi have been telling us for years that the drive battery rated Manufactured Capacity used in the PHEV is 40 Ah and NOT 38 AH that Jeremy used in his formula for working PMC out.

Then we have Daniel (PHEV Watchdog), or someone involved in its development, it seems to me copying (but I may be wrong) Jeremy's EVbatmon (from memory EVbatmon came out first) formula of using 38 Ah instead of what Mitsubishi have been telling us for years to use 40 Ah. So the problem gets even worse because that app can be acquired for free so I think probably more people get involved. :roll:

The worse part for me about this IMO whole sorry mess is some on this forum, from memory, have been blaming Mitsubishi for not using the full rated capacity in that formula or words to that effect when there are people here, that come to this forum, that could have set the record straight of how it all happened in the first place. :roll:

 

[Trex]

In EvBatMon from the beginning I specifically used the label "PMC" which I coined myself as "Percentage of Manufactured Capacity", and not SOH, as I did not believe I was calculating a true SOH value.!

And I think this number is what 95% of the people are interested in.

And I wonder: If PMC has gone down by 10%, can we not assume that SoH has gone down with roughly that same 10%?

Altogether, we know initial available capacity (38 Ah) and we have a notion of current available capacity. As we have no notion of current gross capacity, how is it going to help us if we know initial gross capacity?

Hey anko you are "putting words in my mouth" that I did not say. :lol:

As for your "And I think this number is what 95% of the people are interested in" I think we would have to have a poll to know whether people want to know the "truth" according to Mitsubishi or use the "invented formula" being promoted by you and probably others.

Your "initial available capacity" can be approx 40 Ah, as Mitsubishi has stated, even after the car was delivered it would seem if we believe what was written here:

Further on this, reports are that the BMU shows 40 Ah when the capacity measurement procedure is carried out on the new batteries that are being installed in some Australian cars.

Like I said in a previous post in this thread by not using the rated 40 Ah as Mitsubishi has stated it is not good IMHO because we are speaking different amounts of degradation or SOH in % terms compared to Mitsubishi. :roll: ie when we talk to our dealers or such we are not on the same page or I could say we are comparing apples with oranges IMHO.

 

[anko]

This to me is now starting to sound like a "cop out" or running away from his responsibility for helping create the problem IMO.

To me it seems you are the one creating the problem. IMHO, everybody but you seems happy with how SoH is calculated by either apps.

 

[anko]

Your "initial available capacity" can be approx 40 Ah, as Mitsubishi has stated, even after the car was delivered it would seem if we believe what was written here:

Further on this, reports are that the BMU shows 40 Ah when the capacity measurement procedure is carried out on the new batteries that are being installed in some Australian cars.

Please point me to a report from Mitsubishi for this. I would be very interested to read it.

Like I said in a previous post in this thread by not using the rated 40 Ah as Mitsubishi has stated it is not good IMHO because we are speaking different amounts of degradation or SOH in % terms compared to Mitsubishi. :roll:

Where have they stated this? When I first expressed my concerns with the Dutch distributor I presented them with this calculation: 34.5 Ah out of 40, means 14% loss. They came back with: no, it is 34.5 out of 37.8 Ah, which means 8.7% loss.

I was not happy with that answer, but it was their answer. On the other hand, under the right circumstances the car was able to achieve advertised range. And I was able to add 9 kWh to the battery when charging from empty. So, why focus on that 40 Ah number? Why complain (apart from the fact that I was nowhere near the lower number either)?

Suppose, I buy a car with an engine that is technically capable of producing 200 hp, but do via software restriction of turbo pressure, it has been tuned down to 180 hp. On day 2 I put it on a dyno and it produces 180 hp. Is the SoH of my engine now 80%? I don't think so. Even if other models using the same engine didn't have the restriction and had 200 HP available would not make a difference. SoH of my engine would still be 100%.

 

[Darkflow]

Please point me to a report from Mitsubishi for this. I would be very interested to read it.

You and me both. I'd be interested in reading any report from Mitsubishi about the battery degradation, but won't be holding my breath.

In the meantime though, I assume that you have access to the pooled phev watchdog data that your hard work has enabled to exist.
You'll see data points at 40 Ah representing Australian cars that have new batteries and have had the capacity measurement procedure carried out.

 

[zzcoopej]

Lets just look at that Percentage of Manufactured Capacity wording. To me it looks like he is writing about Mitsubishi's (or GS Yuasa's) Manufactured Capacity. Well Mitsubishi have been telling us for years that the drive battery rated Manufactured Capacity used in the PHEV is 40 Ah and NOT 38 AH that Jeremy used in his formula for working PMC out.

No. Maybe we need to look back to the Mitsu claim which is "There will be some natural degradation of the battery over the life of the vehicle which could lead to a small reduction in the pure EV range. This is expected to be no more than 20%.

So the key points here are -
1. Life of vehicle, not battery. Life starts when the battery is IN the vehicle, not in a brochure or BMU theoretical maximum setting.
2. Reduction is in pure EV range, not Ah, SOH etc.
3. drop of up to 20% in EV range is acceptable after 10 years
4. the 20% is the range when YOU get your PHEV new, vs the range YOU get today.

Unfortunately "pure EV range" opens up a can of worms - what terrain, tyre pressure, roofbars, driving habits, luggage etc? That is why we started using Ah, PMC and SOH as it removes most of those variables.

 

[Trex]

I have some questions for you anko.

Could you please tell me, were you involved in any way with that 38 Ah being used in the formula of either of those 2 apps?

And if the answer is yes which one or was it both?

 

[Trex]

I'd be interested in reading any report from Mitsubishi about the battery degradation, but won't be holding my breath.

I posted this in this thread I started http://www.myoutlanderphev.com/forum/viewtopic.php?f=10&t=3487&start=20 Edit put in wrong link previously

But I now have this information:

"There are two main types of degradation – Cyclic Degradation (degradation due to discharge/charge) and Calendar Degradation (degradation due to time). Factors that
accelerate cyclic degradation are high discharge/charge rates, high energy demands at high/low battery state of charge, and complete battery discharge situations. Factors that
accelerate calendar degradation are amount of time in service, high ambient temperatures in storage (when the vehicle is not in use) and high battery state of charge when in
storage."

IMO this helps us solve this one.

Regards Trex.

This is straight from the "horse's mouth" and sent to me personally, though not one person asked me at the time where I got it or I am not sure anyone even noticed it at the time.