Drive battery degradation and replacement.

[HHL]

Hi folks,

As my old degradation thread is now 36 pages :shock: long I will start a new one here as the old one has a lot of out of date information.

Now just to catch up of where I am currently with my oldest PHEV's drive battery which my oldest son now drives is we had below 80% SOH (about 77%) in Feb 2018.

After stuffing about with different dealers where the first could not get his MUT-III to communicate with my PHEV I finally got another dealer to get some tests done. It was there where they did a battery smoothing (cell balancing from what I could see) and a Auto Capacity Measured Procedure which empties the battery and measures what it takes to refill it and then adjusts the BMU SOH to include the new result. For me it took the SOH up to about 81% . Now the other day my son and I checked his drive battery and it was showing about 72% SOH so the gain did not last long so I will be trying to get a new drive battery before the 5 year warranty runs out in April.

But will have probably have to get another Auto Capacity Measured Procedure done again though.

Regards Trex.

After getting my oldest Phev's drive battery recalibrated again and the SOH went up to approx 75% and the data sent to MMAL, and been told by MMAL that they will NOT replace my drive battery.

So if you are a whinging German on youtube that moves to Australia and he buys a 2nd hand PHEV, from memory, you get your battery replaced. But if you buy 2 PHEVs brand new and was born and bred here no such luck.

Yep, sounds fair to me. :lol:

As an engineer, you should know that the squeaky wheel gets the grease! :lol:

 

[Darkflow]

Here are a couple of graphs from a recent unplugged ev youtube video. The first is Andy's car showing (in the brighter dots) his old battery on the left and brand new one on the right:

This next one shows data from the 2019 models:

Note the same rapid / almost vertical pattern of decreasing calculated SOH.

Yet older data does not show this pattern.

Is this whole thing simply an issue with the updated BMU software? Does anyone have data from a car before and after the latest BMU update?

 

[Trex]

After getting my oldest Phev's drive battery recalibrated again and the SOH went up to approx 75% and the data sent to MMAL, and been told by MMAL that they will NOT replace my drive battery.

So if you are a whinging German on youtube that moves to Australia and he buys a 2nd hand PHEV, from memory, you get your battery replaced. But if you buy 2 PHEVs brand new and was born and bred here no such luck.

Yep, sounds fair to me. :lol:

As an engineer, you should know that the squeaky wheel gets grease! :lol:

:lol: :lol:
But as a engineer I know that all the wheels should get greased to stop a squeaky wheel showing up.

I think I am also starting to get an appreciation for the saying "Whinge and Win" because people will look after you just to hopefully shut you up. :lol: .

 

[Trex]

Is this whole thing simply an issue with the updated BMU software?

Hi Darkflow,

Like I wrote previously in this thread:

I am not sure about this statement HHL. Now from the person on youtube I posted above says:

"Had the 2018 phev since Feb. After 20.000 km and battery capacity down to 93%according to watchdog, had car inspection and they suggested battery reprogramming, and they did a dbcam procedure. Since then battery capacity upto and remains at 98,5% and have driven 1000 km. My garage(Germany) doesn't understand all these problems, so the most important thing when buying a phev, which I love and am very happy with it.,is the 3xperience and quality of expertise at your garage. The extra education of the mechanics is expensive so my garage tells me."

Now we cannot tell from this if the person used DC charging but reading what he said made me go and check my new April 2018 PHEV and saw that the SOH was 91.84% with only 12,823 kms using EVbatmon. So according to the BMU I have lost approx 8% in approx 9 months with no DC charging and we have been babying the new PHEV's drive battery far more than my oldest PHEV.

Speaking of which ie my oldest PHEV you asked me back in the old Evbatmon thread I started:

Same here... works a treat.

Use an old Nextbook to run it. Very impressive....

My battery % is 91.4% (car built date is Mar 2014, 11,000km)

Care to share your info?

Sure.

Battery condition 90%.

Car built Feb 2014(bought April 2014), 31,415kms

Now this was posted Sun Dec 27, 2015 so nearly 2 years after it was built my oldest PHEV that we did not baby is approx the same as my new PHEV that we do. :roll:

Do I think my new PHEV is degraded this bad for real? No I do not. I think the BMU is being very pessimistic on the new PHEVs as some around here have noticed including the person I quoted above.

Will I bother to get my BMU recalibrated at this stage? Not sure. I may wait to see because it is not effecting the range we need while EVing but I would love to know for sure like the person I quoted above just to satisfy my curiosity.

Notice that section I wrote "I think the BMU is being very pessimistic on the new PHEVs as some around here have noticed including the person I quoted above."

This is what I think is shown in that 2019 model year graph you posted and to a lot of the other newer models including my 2018 model.

Now Mitsubishi have supposedly released a BMU update Ref C1811R.

Now my newest PHEV is due for its 1st service in early March 2019 ie a couple of weeks away and I am booked in to get a BMU recalibration (or "Auto Capacity Measured Procedure") and that BMU update done. Will let you know how I go.

Regards Trex.

 

[HHL]

Notice that section I wrote "I think the BMU is being very pessimistic on the new PHEVs as some around here have noticed including the person I quoted above."

This is what I think is shown in that 2019 model year graph you posted and to a lot of the other newer models including my 2018 model.

Now Mitsubishi have supposedly released a BMU update Ref C1811R.

Now my newest PHEV is due for its 1st service in early March 2019 ie a couple of weeks away and I am booked in to get a BMU recalibration (or "Auto Capacity Measured Procedure") and that BMU update done. Will let you know how I go.

Regards Trex.

the update will possibly lock out the "watchdog" so people don't get the "Black Dog" after looking at the data :shock:

 

[elm70]

Here are a couple of graphs from a recent unplugged ev youtube video. The first is Andy's car showing (in the brighter dots) his old battery on the left and brand new one on the right:

Note the same rapid / almost vertical pattern of decreasing calculated SOH.

Yet older data does not show this pattern.

Is this whole thing simply an issue with the updated BMU software? Does anyone have data from a car before and after the latest BMU update?

When they did update the BMU firmware ?

I got my car serviced 4 months ago, and I did not find anything different in the BMU .. except ... I believe my car stop the charging process earlier then the past ... possibly it was a bit overcharged before, helping on a bit of extra range, but at a cost of faster battery degradation if car left fully charged for too long.

There is an easy way to verify if the SOH know by the BMU is correct.

Car need to be driven in EV mode ideally till EV range is zero. Ideally in one shot, not into multiple segment .
After the "long" EV trip, car should be left unused without any charge , for over 2h.
After this time, it should be compared the SOC immediately after the trip and end after the rest. This the SOC is unchanged .. the BMU has a good idea about the SOH .. if the SOC goes significantly up, then SOH is underestimated .. it SOH does significantly down .. SOH is optimistic

I did monitor this on my PHEV .. and I find that SOH knowledge from the BMU is always a bit optimistic .. this is why the SOH is slowly declining over time .. I also find out that voltage after rest and after a trip, comparing two different time (months apart) but same trip .. show that this voltage is declining .. so .. yes SOH lost is real an not virtual.

I don't see how they could made a big mistake in the BMU firmware that could cause to have a pessimistic view on the SOH ... I believe some battery has less capacity then expected in the defined voltage bandwidth that is 4.10v down to 3.81v (30% SOC) ... since Mitsubishi decided to use the battery between these two voltage levels .. it is quite pointless to know if there is tons of capacity in AH left below 3.81V (rest voltage)

 

[elm70]

the update will possibly lock out the "watchdog" so people don't get the "Black Dog" after looking at the data :shock:

They will have to make lot of ECU firmware changes for make the watchdog blind

It will be also a bad decision ... I think people should know what is the real SOH of their battery .

 

[anko]

They will have to make lot of ECU firmware changes for make the watchdog blind.

Not perse. Just disable data item #18 in the BMU ECO PID list. Unfortunately, their MUT-III devices wouldn't be able to establish the capacity either, as they work exactly the same way.

 

[Darkflow]

Thanks for the replies.

When they did update the BMU firmware ?

An assumption on my part, which may well be wrong. After getting the "ICE may not start" recall service done, my predicted battery range went up from 50km to 75km and then slowly decreased to normal with driving, so I assumed that there may have been a BMU update.

I don't see how they could made a big mistake in the BMU firmware that could cause to have a pessimistic view on the SOH ...

But if that is true, what is happening with the new models? On the trajectory they are showing, they'll be down to something like 70% SOH in a year or so. That can't be right.

Also, why is unplugged ev Andy's brand new battery showing the same behaviour, both the same as his old battery, and the same as the new larger battery models?

 

[elm70]

They will have to make lot of ECU firmware changes for make the watchdog blind.

Not perse. Just disable data item #18 in the BMU ECO PID list. Unfortunately, their MUT-III devices wouldn't be able to establish the capacity either, as they work exactly the same way.

It does not sound a simple change.
They can't make their tools blinds to SOH
:ugeek:

 

[elm70]

I don't see how they could made a big mistake in the BMU firmware that could cause to have a pessimistic view on the SOH ...

But if that is true, what is happening with the new models? On the trajectory they are showing, they'll be down to something like 70% SOH in a year or so. That can't be right.

Also, why is unplugged ev Andy's brand new battery showing the same behaviour, both the same as his old battery, and the same as the new larger battery models?

Just looking at fuel level and not checking how much goes in and out .. is pointless

So ... cheking only SOH, and have no idea how far this is accurate, by monitoring the voltage/SOC update after rest and usage .. is quite pointless

Looking only at SOH change does not give any idea what is going on.

For what we know .. SOH drop could stop dopping at any point

Bad firmware is less lickley then a battery which has been wrongly initiated in the BMU with an overstated capacity.

As I mention above, what matter is the capacity in a particular voltage range ... what happen outside (which can have huge impact on real capacity) is irrelevant.

 

[plugev]

Hi guys,

I bought my 2015 Outlander PHEV in March 2018 with 26,000kms and it read a battery SOH of 84%. Now less than a year later it reads 76.3% with less than 35,000kms. Does this seem acceptable

Gday plugev,

I suppose the first thing I would ask is are you having trouble getting to your destination in EV on your daily commute?

Now we have a transferable 5 year warranty, from memory, before anything else that may apply so you have time on your side IMO.

But only you can decide whether the lack of range is affecting you.

Now if you decide that you want to do something about your drive battery then we can talk about that later but I am pretty sure you will need to get your BMU (Battery Management Unit ) recalibrated to show the true capacity or SOH. Just look back earlier in this thread to see what I am talking about.

Also, the car is due for a 3yr service and I have been quoted $930, $850 and $680 to do the service (in Brisbane, Australia), do these amounts seem reasonable for what looks like a basic oil/filter change, a pollen filter, plus 'looking at' a list of things?

Ok to me those amounts sound excessive but my dealer is in a "town" in NSW compared to a city like Brisbane where they seem to know how to charge more for even a basic service like a schooner of beer.

Now I have just had a 5 year service done on my oldest PHEV (bought new) about 2 weeks ago so I will have a look around and see if I can see the price I paid for the 3 year service a couple of years ago.

Regards Trex.

Thanks Trex,

It doesn't affect my weekday commute which is only 14kms a day. But on the weekend and occasional longer weekday trip, I can't quite reach the destinations I could before without using the ICE. My warranty is until Dec 2020 so I do have time on my side, it is disappointing though to have such poor range when the car hasn't done much milage.

Using some petrol is probably no big deal since the car needs to use some regularly anyway, but I think it affects me because the car drives much better in EV only mode. The ICE is comparatively quite noisy and harsh.

Perhaps significant degradation is inevitable whether the battery gets replaced or not in these cars, as the battery is small and gets cycled so regularly and completely. I guess the problem is the way Mitsubishi sold the product claiming it will make 52kms on EV mode, when in reality after a couple years of use the car can only do 30km or less with ordinary use.

 

[HHL]

Hi guys,

I bought my 2015 Outlander PHEV in March 2018 with 26,000kms and it read a battery SOH of 84%. Now less than a year later it reads 76.3% with less than 35,000kms. Does this seem acceptable?

Also, the car is due for a 3yr service and I have been quoted $930, $850 and $680 to do the service (in Brisbane, Australia), do these amounts seem reasonable for what looks like a basic oil/filter change, a pollen filter, plus 'looking at' a list of things?

Thanks

Those quotes are certainly a bit steep, as you already worked out yourself. I had that service (and the 4 year one) done for $470.00 at a dealership 100km away because the local guys didn't want my business , they also quoted about $900.00 and when I pointed out that it is not much more than an oil change, they referred to the Mitsu schedule that allows something like 3.5 hours... at $186.00 per hour... we certainly are getting a bit greedy.

 

[jaapv]

Hi guys,

I bought my 2015 Outlander PHEV in March 2018 with 26,000kms and it read a battery SOH of 84%. Now less than a year later it reads 76.3% with less than 35,000kms. Does this seem acceptable

Gday plugev,

I suppose the first thing I would ask is are you having trouble getting to your destination in EV on your daily commute?

Now we have a transferable 5 year warranty, from memory, before anything else that may apply so you have time on your side IMO.

But only you can decide whether the lack of range is affecting you.

Now if you decide that you want to do something about your drive battery then we can talk about that later but I am pretty sure you will need to get your BMU (Battery Management Unit ) recalibrated to show the true capacity or SOH. Just look back earlier in this thread to see what I am talking about.

Also, the car is due for a 3yr service and I have been quoted $930, $850 and $680 to do the service (in Brisbane, Australia), do these amounts seem reasonable for what looks like a basic oil/filter change, a pollen filter, plus 'looking at' a list of things?

Ok to me those amounts sound excessive but my dealer is in a "town" in NSW compared to a city like Brisbane where they seem to know how to charge more for even a basic service like a schooner of beer.

Now I have just had a 5 year service done on my oldest PHEV (bought new) about 2 weeks ago so I will have a look around and see if I can see the price I paid for the 3 year service a couple of years ago.

Regards Trex.

Thanks Trex,

It doesn't affect my weekday commute which is only 14kms a day. But on the weekend and occasional longer weekday trip, I can't quite reach the destinations I could before without using the ICE. My warranty is until Dec 2020 so I do have time on my side, it is disappointing though to have such poor range when the car hasn't done much milage.

Using some petrol is probably no big deal since the car needs to use some regularly anyway, but I think it affects me because the car drives much better in EV only mode. The ICE is comparatively quite noisy and harsh.

Perhaps significant degradation is inevitable whether the battery gets replaced or not in these cars, as the battery is small and gets cycled so regularly and completely. I guess the problem is the way Mitsubishi sold the product claiming it will make 52kms on EV mode, when in reality after a couple years of use the car can only do 30km or less with ordinary use.

It is not cycled completely. When it indicates "empty" it still has about 30% left. It will never go below 25% charge. Similarly, it will never charge to full capacity.

 

[anko]

It will never go below 25% charge. Similarly, it will never charge to full capacity.

I have seen 18% during normal operation. I could agree with 'very seldom'

 

[jaapv]

OK Very seldom. How did you manage to get that low?

 

[anko]

OK Very seldom. How did you manage to get that low?

Quite easy. Hook up a 1500 kg caravan, travel the A75 in the South of France north bound, from Beziers towards Milau and set your cruise control to 90-ish km/h. Gaining about 1000 meters at motorway speed will cause SoC to drop quickly, especially while in parallel mode. At 20% SoC the car will switch from paralel mode to series mode, but even in series mode, the ICE will not be able to maintain (let alone increase) SoC. So, SoC will continue to drop until you really experience "reduced propulsion" mode.

 

[elm70]

OK Very seldom. How did you manage to get that low?

This weekend I manage to see my lowest SOC while driving.

I had lot of city driving which allow to go down to 25% SOC

And then, since it was a bit cold, once I enter on a fast road, it took sometime before create enough power from the ICE .. so .. lowest value recorder by the WatchDog was 22.0% or 7.4Ah or 280v (3.5v per cell)

I think Anko did mention multiple times .. the buffer on the bottom, it is also needed for give time to the ICE to properly getting ready to charge the battery and give a smooth transition to the driver without any situation with limited power

Still it is a bit odd to have multiple "lowest" SOC level .. 30% (if car is drive faster then 60km/h) .. 25% for slow driving (which does not implies that driver can speed up at any time) .. and there is another level which might cause limited power ... if it would be me .. I would have gone for 27.5% for both high and low speed .. so with a more consistent EV range prediction. But I'm not Japanese enough :mrgreen:

 

[STS134]

OK Very seldom. How did you manage to get that low?

I went up this climb in Charge mode. Started with 14/16 bars on the gauge. Finished with 8/16 bars on the gauge. The climb consumed ~3.3 kWh (it's about 0.55-0.6 kWh per bar) in about 8-9 minutes, which is approximately a steady state power drain of 23 kW or around 2C. In SoC terms, I think this was about 25% or so.
https://www.google.com/maps/dir/34.9394499,-118.9308095/34.8029275,-118.8772576/@34.859895,-118.926194,12.5z/data=!4m2!4m1!3e0!5m1!1e4

If I had started with the standard 30% SoC, I would have hit 0 bars (25%) VERY quickly. And would probably have dropped to 15% about half way up, at which point, the car would have gone into limp mode.

 

[anko]

I went up this climb in Charge mode. Started with 14/16 bars on the gauge. Finished with 8/16 bars on the gauge. The climb consumed ~3.3 kWh (it's about 0.55-0.6 kWh per bar) in about 8-9 minutes, which is approximately a steady state power drain of 23 kW or around 2C. In SoC terms, I think this was about 25% or so.
https://www.google.com/maps/dir/34.9394499,-118.9308095/34.8029275,-118.8772576/@34.859895,-118.926194,12.5z/data=!4m2!4m1!3e0!5m1!1e4

If I had started with the standard 30% SoC, I would have hit 0 bars (25%) VERY quickly. And would probably have dropped to 15% about half way up, at which point, the car would have gone into limp mode.

Not perse. As this was an Interstate, you were probably in Parallel mode most of the time (if not all the time). If so, the car would have reverted to Series hybrid mode as soon as you hit 20% SoC, allowing for more RPM (and thus more ICE power).

When towing a caravan, I often see SoC dropping to 20% in parallel mode and then climbing back up to 22% in Series mode. And so on. This is sort of a secondary hysteresis cycle. Of course, while towing speed is relatively low (60-ish MPH) and so is RPM in parallel mode. Therefor the difference in max power output of the ICE in Series mode versus Parallel mode is rather large. If you were going faster during your climb, the difference may in max power output may have been smaller. But still, it might have kept you out of limp mode.