Evbatmon and Phev watchdog is showing the wrong SOH amount.

[anko]

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?

No, why? Do you think I am biased? ;-)

 

[Trex]

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.

:lol: :lol:

No you are right anko, I caused this problem:

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%.

and this:

.......................... 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................ :

Yes I am creating these problems. :lol:

 

[Trex]

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.

I am not sure who you are referring to here. Can you be more specific? I was referring to Mitsubishi telling us we have a 40 Ah rated drive battery.

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?

Where have they stated what? That we have a 40 Ah rated drive battery? Just look at that the first post in this topic to see where you can see this shown. Or are writing about this bit?:

............ because we are speaking different amounts of degradation or SOH in % terms compared to Mitsubishi. :roll:

If we get our BMU recalibrated BMU data list number 401 Cell current capacity difference amount expressed in % terms will be different to the apps because Mitsubishi are comparing it to a 40 Ah rated battery and not the invented 38 Ah formula.

They came back with: no, it is 34.5 out of 37.8 Ah, which means 8.7% loss.

And you believed the Dutch distributor over what Mitsubishi Motors have stated in their literature? ie That we have a 40 Ah rated battery. Pretty sure I would not have let them get away with this unless I was unaware of that literature.

 

[Trex]

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%.

Let me fix that for you as is more relevant to this topic IMHO. Suppose, I buy a car with an engine that has been told to us by the manufacturer is capable of producing 200 hp, but through ageing and/or (edit) estimating and/or badly calibrated software that now only produces 180 hp. I am sure you can see where I am going with this.

Anko you are making all this to easy for me IMHO because no matter how you try to justify that "invented" 38 Ah battery formula I can just come back with Mitsubishi's own examples to show that it is a rated 40 Ah battery.

Do I believe you or Mitsubishi. Sorry, I believe the engineers and technicians etc of the manufacturer over a "invented" formula by others any day.

 

[Trex]

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.

Jeremy just what the hell does a, from memory, Mitsubishi Australia statement have to do with this thread's topic.? :? :roll:

Looks like you just want to change the subject to me.

 

[anko]

Trex,

IMHO you are missing my point. I have not said (or meant to say) the battery cells are not rated 40Ah. I also believe that the physical capacity is 40 Ah. I am just saying that (maybe in order to protect the battery) less than the full 40 Ah have been made available to us. What the BMU reports is what is available to us (usable capacity).

If you want to discuss degradation, you should compare current usable capacity to usable capacity when new. Or current physical capacity (which we simply don't know) to physical capacity when new. Not current usable capacity to physical capacity when new. Because that is apples and oranges if you ask me.

If the physical capacity when new was 40 Ah, but the usable capacity was only 38, it would still be a 12 kWh pack. Or did Mitsubishi tell you it was 12 kWh usable? For sure you have always known it wasn't.

 

[Zuikkis]

Yuasa states the battery cells are 40Ah, when charged to 4.2V. Mitsu only charges to 4.1V. This difference alone makes the 40Ah -> 38Ah difference.

IMHO 38Ah is much more logical reference in the app, because that is the real Ah when battery is fitted to car..

Edit: And yeah, BMU is reporting the current SOH as "Ah when charged to 4.1V". It's impossible to know what SOH would be when charged to 4.2V, so it would be useless to use 40Ah as comparison.

 

[ErwinD]

Tell me if it's not the right place to write this, but I'm new to this forum:

3 days ago, I bought a "demo" (6 months old - 1580 km) belgian 2019 PHEV (2.4 litre) which has a battery pack capacity increased by 10% to 13.8 kWh.
13.8 kWh / 300V = 46 Ah

The watchdog "Battery Condition" is:
95.7% = 42.1 Ah => 100% = 44 Ah (46-44 = 2 = 40-38)

After a full charge, I got the following Watchdog-data:
- Capacity: 110.8% = 42.1 Ah => 100% = 38 Ah (Watchdog uses 38 Ah even for 46 Ah batteries !)
- 100.7% = 42.4 Ah => 100% = 42.1 Ah

What do you think about this numbers ?

 

[Trex]

Trex,

IMHO you are missing my point. I have not said (or meant to say) the battery cells are not rated 40Ah. I also believe that the physical capacity is 40 Ah. I am just saying that (maybe in order to protect the battery) less than the full 40 Ah have been made available to us. What the BMU reports is what is available to us (usable capacity).

If you want to discuss degradation, you should compare current usable capacity to usable capacity when new. Or current physical capacity (which we simply don't know) to physical capacity when new. Not current usable capacity to physical capacity when new. Because that is apples and oranges if you ask me.

If the physical capacity when new was 40 Ah, but the usable capacity was only 38, it would still be a 12 kWh pack. Or did Mitsubishi tell you it was 12 kWh usable? For sure you have always known it wasn't.

Anko,

I will try to make it easier for you to understand. The BMU is a "estimator" of current capacity. Let's put it another way. The BMU is just "guessing". It is not "real" current capacity unless the BMU has been calibrated recently.

When the BMU is calibrated through the Auto Capacity Measured Procedure by emptying the battery and then measuring the current X the time (Edit when charging) Mitsubishi compare the result with a 40 Ah rated battery. NOT a 38 Ah battery. Of course this is on the older models PHEVS without the bigger drive battery.

People here in Australia that are getting their BMU calibrated for their new batteries are seeing that approx 40 Ah just like Mitsubishi have been telling us is in the PHEV.

Mitsubishi have told us under most circumstances approx 8.4 kWh is usable, when the battery is new, out of that 12 kWh drive battery because of the bottom side buffer.

The apps are using a "invented" by Jeremy battery formula from what I can see and have been told.

I trust Mitsubishi more than Jeremy, yourself or even the BMU (if not calibrated) when Mitsubishi compare "real" current capacity to a "real" 40 Ah rated battery.

Edit Even if the "guessing" BMU only let us use 38 Ah at the start of ownership of our PHEV why should we use a "invented" SOH or PMC formula when Mitsubishi do NOT in their expressed measurement of "real" degradation. Errr, to me " That does not compute" :lol: Just too much "guessing" and "inventing" for my liking. Let's keep things "real", man. :lol:

 

[Trex]

Yuasa states the battery cells are 40Ah, when charged to 4.2V. Mitsu only charges to 4.1V. This difference alone makes the 40Ah -> 38Ah difference.

IMHO 38Ah is much more logical reference in the app, because that is the real Ah when battery is fitted to car..

Edit: And yeah, BMU is reporting the current SOH as "Ah when charged to 4.1V". It's impossible to know what SOH would be when charged to 4.2V, so it would be useless to use 40Ah as comparison.

GS Yuasa has not stated battery cells are 40Ah, when charged to 4.2V anywhere I can find. Please show me where I can see this.

If you cannot show me I think you will look "silly" for writing any of what you wrote in that post Zuikkis.

 

[Trex]

Tell me if it's not the right place to write this, but I'm new to this forum:

3 days ago, I bought a "demo" (6 months old - 1580 km) belgian 2019 PHEV (2.4 litre) which has a battery pack capacity increased by 10% to 13.8 kWh.
13.8 kWh / 300V = 46 Ah

The watchdog "Battery Condition" is:
95.7% = 42.1 Ah => 100% = 44 Ah (46-44 = 2 = 40-38)

After a full charge, I got the following Watchdog-data:
- Capacity: 110.8% = 42.1 Ah => 100% = 38 Ah (Watchdog uses 38 Ah even for 46 Ah batteries !)
- 100.7% = 42.4 Ah => 100% = 42.1 Ah

What do you think about this numbers ?

Ok ErwinD, I read the battery pack was increased by 15%, from memory, more capacity to 13.8 kWh on the newer PHEVs ie (.15 x 12 kWh) + 12 kWh = 13.8 kWh

Where you say "(Watchdog uses 38 Ah even for 46 Ah batteries !)" it also uses 38 Ah for a 40 Ah rated battery as well!

I will check through your calcs when I get a chance later I hope.

Got to go.

Regards Trex.

 

[ErwinD]

Where you say "(Watchdog uses 38 Ah even for 46 Ah batteries !)" it also uses 38 Ah for a 40 Ah rated battery as well!

1. I suppose these 38 Ah are a fixed Watchdog parameter (= not read from the OBD2).
Maybe the Watchdog settings should have a setting "type of battery" = [40 (or 38?)] vs [46 (or 44?)] to give a more significant % (for the cars with an increased battery pack capacity) ?

2. Meanwhile (after 4 days, ± 250 km driving and 1 full charge) the SOH went from 95.7% = 42.1 Ah to 95.5% = 42.0 Ah