Drive battery degradation . Houston, do we have a problem?

[AndyH]

...and should open the door to a 2nd life for our PHEV ... which at the moment is getting more and more close to a traditional hybrid car then not a EV car with short but useable range

This right here is why I absolutely HATE GM for coining the phrase "range extended electric vehicle" for their Volt/Ampera. I'm looking at you, Bob Lutz. :evil: There's already a definition for these vehicles - they're called PHEVs. They're further broken down by range. We drive "PHEV-20" (miles, sorry, not KM). The Volt/Ampera was a PHEV-40 when it launched.

rant
Idiot automakers making up marketing terms to confuse the buying public have people thinking that their PHEVs are actually 'electric vehicles' and they get upset when their range goes down.
/rant

ALL batteries degrade even when they're not used - it's chemistry and physics. Our cars are guaranteed to be plug-in hybrids, but EV range is not guaranteed. It's like playing American football. You know you're going to get hurt - might as well get some mileage out of it anyway. :lol:

 

[greendwarf]

This right here is why I absolutely HATE GM for coining the phrase "range extended electric vehicle" for their Volt/Ampera. I'm looking at you, Bob Lutz. :evil: There's already a definition for these vehicles - they're called PHEVs. They're further broken down by range. We drive "PHEV-20" (miles, sorry, not KM). The Volt/Ampera was a PHEV-40 when it launched.

Maybe, but it "does what it says in the tin" as we say in UK - PHEV or even Plug in Hybrid Electric Vehicle, is arguably less informative. :roll:

 

[elm70]

...and should open the door to a 2nd life for our PHEV ... which at the moment is getting more and more close to a traditional hybrid car then not a EV car with short but useable range

This right here is why I absolutely HATE GM for coining the phrase "range extended electric vehicle" for their Volt/Ampera. I'm looking at you, Bob Lutz. :evil: There's already a definition for these vehicles - they're called PHEVs. They're further broken down by range. We drive "PHEV-20" (miles, sorry, not KM). The Volt/Ampera was a PHEV-40 when it launched.

rant
Idiot automakers making up marketing terms to confuse the buying public have people thinking that their PHEVs are actually 'electric vehicles' and they get upset when their range goes down.
/rant

ALL batteries degrade even when they're not used - it's chemistry and physics. Our cars are guaranteed to be plug-in hybrids, but EV range is not guaranteed. It's like playing American football. You know you're going to get hurt - might as well get some mileage out of it anyway. :lol:

Some batteries are consider to have over 100y life time (this is the record "holder" : https://motherboard.vice.com/en_us/article/9akg9d/this-battery-has-lasted-175-years-and-no-one-knows-how) ... Lithium battery, when build up properly and stored at 3.8v can have almost no degradation after years

Tesla batteries are reported to keep well over 90% after 400.000km and multiple years of usage.

PS: In my modest opinion they took the wrong type of battery for our PHEV .. our battery internal resistance (IR) is too high for the designed usage ... our battery is supposed to deliver 60kw and recharge at 35kw ... and it is just a little 12kwh pack .. so it is discharged at 5C and charge at 3C ... at these power level ... the high IR cause up to 10% energy waste only on the battery, and does accelerate the degradation

I know for fact that there are Lithium battery capable to handle over 100C ... possibly having selected a low IR battery could have not only improved the efficiency but as well increase the SOH over years ...

Anyhow ... next generation of solid state battery are looking to check all the boxes ... so .... it has to be seen if the SS Batteries will be available before my PHEV will get useless for the daily commute ...

PS: A car life expectation is consider 15y ... battery degradation with less then 80% SOH after 3 years .. don't sound good for be able to reach 15y of car life

 

[AndyH]

...and should open the door to a 2nd life for our PHEV ... which at the moment is getting more and more close to a traditional hybrid car then not a EV car with short but useable range

This right here is why I absolutely HATE GM for coining the phrase "range extended electric vehicle" for their Volt/Ampera. I'm looking at you, Bob Lutz. :evil: There's already a definition for these vehicles - they're called PHEVs. They're further broken down by range. We drive "PHEV-20" (miles, sorry, not KM). The Volt/Ampera was a PHEV-40 when it launched.

rant
Idiot automakers making up marketing terms to confuse the buying public have people thinking that their PHEVs are actually 'electric vehicles' and they get upset when their range goes down.
/rant

ALL batteries degrade even when they're not used - it's chemistry and physics. Our cars are guaranteed to be plug-in hybrids, but EV range is not guaranteed. It's like playing American football. You know you're going to get hurt - might as well get some mileage out of it anyway. :lol:

Some batteries are consider to have over 100y life time (this is the record "holder" : https://motherboard.vice.com/en_us/article/9akg9d/this-battery-has-lasted-175-years-and-no-one-knows-how)

Nobody can really say that the same power source has been running that bell for 100 years - and the power draw is so microscopic they'd get better performance with some nails in a lemon. That's not applicable to electric transportation or cell phones or even illuminating a single LED.

... Lithium battery, when build up properly and stored at 3.8v can have almost no degradation after years

What kind of lithium battery 'almost' doesn't degrade after years? Lithium titanate? Lithium nickel cobalt aluminum oxide? LiFePO4? LiFeYPO4? Lithium cobalt oxide? Lithium nickle manganese cobalt oxide? Lithium manganese oxide? There's no such think as a 'lithium battery' with specific characteristics. Each of the different anode and cathode compositions, plus electrolyte chemistries, plus separator type has very different characteristics and voltages.

Tesla batteries are reported to keep well over 90% after 400.000km and multiple years of usage.

PS: In my modest opinion they took the wrong type of battery for our PHEV .. our battery internal resistance (IR) is too high for the designed usage ...

What type of cell should they have used? And what is the Ri for our cells when new and when they have 100km of experience?

Cell life is about much more than just chemistry or how much energy we spike in and out. Thermal management is a huge factor. Tesla (and my smart) have lower rates of degradation not because of cell chemistry (each uses a different type of battery) and not because of current demand or regen rates, but because of the liquid heating/cooling.

One example of how to abuse a battery of any type: Start with an extremely cold battery pack, don't pre-heat or allow the ICE to run, then drive 20km to work. The poor battery has very high Ri, the chemical reactions are slow, and much of the energy liberated in the cell is converted to heat. Pre-heating or pre-cooling is a battery lifesaver.

 

[elm70]

ALL batteries degrade even when they're not used - it's chemistry and physics. Our cars are guaranteed to be plug-in hybrids, but EV range is not guaranteed. It's like playing American football. You know you're going to get hurt - might as well get some mileage out of it anyway. :lol:

Some batteries are consider to have over 100y life time (this is the record "holder" : https://motherboard.vice.com/en_us/article/9akg9d/this-battery-has-lasted-175-years-and-no-one-knows-how)

Nobody can really say that the same power source has been running that bell for 100 years - and the power draw is so microscopic they'd get better performance with some nails in a lemon. That's not applicable to electric transportation or cell phones or even illuminating a single LED.

Possibly I was using the wrong reference ... but there are already technology for make long lasting batteries: like http://www.zappworks.com/ (which clearly can't be used on an EV, or will not make much sense)

I'm quite sure already now lithium cells can be designed to be more or less resilience with a different possible life time ... I don't know if Tesla cells have longer life due to the temperature management ... but something is telling me that the very long experience from Panasonic on Lithium cells, does play a huge role .... something that GS Yuasa does not have.

 

[anko]

Back to Outlander PHEV battery degradation I just took my (by now) wife's car for a spin, and found that the engine kicks in when power demand is about 40 kW, even when increasing power demand very, very slowly. At max throttle, combined output of the E-motors is about 104 - 105 kW, where it IMHO should be 120 kW. I know this from monitoring RPM and Torque of both E-motors. But also, the needle does not go as far in the white as it did before (kind a up to the 2:30PM position, rather than up to the 3:15PM position) So, like it said before, it is not just energy that ids affected, but also power. Has a big impact on drivability, as even within the city limits, it is difficult to drive pure EV.

 

[AndyH]

Possibly I was using the wrong reference ... but there are already technology for make long lasting batteries: like http://www.zappworks.com/ (which clearly can't be used on an EV, or will not make much sense)

I'm quite sure already now lithium cells can be designed to be more or less resilience with a different possible life time ... I don't know if Tesla cells have longer life due to the temperature management ... but something is telling me that the very long experience from Panasonic on Lithium cells, does play a huge role .... something that GS Yuasa does not have.

Zappworks and other nickle/iron 'Edison' cells are expensive, and as long as the battery box holds up, and as long as the electrolyte is replaced at regular intervals, they do last a long time. They're less efficient than lead acid. And those electrolyte changes? They're more expensive than buying a new set of cells. (Not trying to give you a hard time. I researched and tested different sorts of batteries for an off-grid house project. Nickel/iron would have cost me more than a LiFePO4 pack, I would have had to add at least 1/3 to the solar array to make up for the inefficiency of the cell, and the cost of electrolyte changes would mean I'd need to pay the same amount of money over time that I would if I simply replaced the entire battery bank every three years. It's insane.)

LiFePO4 was in a lab in 1996. LiCoO2 are a bit older. No doubt Panasonic knows how to make consistent cells. But Tesla packs don't last longer just because of the shrink wrap. My smart has had nothing more than normal time-based degradation in the 3 years I've owned it - and the cells aren't cylindrical laptop cells and they're not LiCo - they're a LiNiMnCoO2. So...different cell manufacturer, different cell structure, different chemistry, similar charge and discharge loads relative to a single cell, and both using active liquid thermal management. The same can be said for the Volt/Ampera - they started with LiFePO4 cells from A123 and moved to a LiMn variant from LG-Chem 'cause they're less expensive and a bit lighter. Same liquid thermal management. Very little degradation beyond that expected. This is important: Chemical cells lose capacity sitting on the shelf in the dining room. Literally. That's where I hand made battery packs and I still have 50 cylindrical LiFePO4 cells in boxes in my house that I keep for my projects and for any warranty replacements. They started as 11Ah cells 6 years ago. I change them, discharge them to 50% for storage every 2 years. They're down to about 9Ah now. There's nothing Mitsubishi can do to stop cells from losing capacity. Entropy's a real thing. That's all I'm trying to communicate.

We don't drive EVs - we drive hybrids. Use shore power to pre-heat or pre-cool the battery. Use petrol. The car MUST use petrol - we're going to burn it in regular use, or we're going to burn it when the computer requires it to keep the fuel from destroying the pumps and injectors. Use some of the energy we have to use anyway to 'baby' the lithium battery. That's my plan, anyway.

 

[Harald]

... and found that the engine kicks in when power demand is about 40 kW, ...

I think the car should do this, when the demand is above 30 kW (or 100 A) from the battery?

 

[anko]

I think the car should do this, when the demand is above 30 kW (or 100 A) from the battery?

The battery can source 60 kW (as a matter of fact, a little bit more, IIRC). When you operate the throttle very careful, you can get the power needle in the 12 o'clock position (which resembles 60 kW) without starting the ICE (hence the green part of the first section). In order to get past the green section you definitely do need the ICE.

Also, when pressing the throttle quickly, the ICE will start well before you reach the 12 o'clock position. It sort of anticipates a higher power demand. For this to work, next to a position sensor there is also an accelerometer in the throttle. Together, they determine when the ICE will be started. Of course, also power demand from the electric heater must be taken into consideration. But when I wrote the ICE kicked in at 40 kW, I was not reading that from the power needle, but from monitoring Amps in/out of battery + battery voltage.

BTW: part of what the PHEV Box does, is nullify the output of the accelerometer, so that you will not accidentally start the ICE when you kick the throttle going over a speed bump

 

[Harald]

Thanks Anko.

It seems that I was tired yesterday as I forgot the limit was 60 kW, not 30 kW....

Harald

 

[anko]

Thanks Anko.

It seems that I was tired yesterday as I forgot the limit was 60 kW, not 30 kW....

Harald

Happens ....

 

[anko]

We don't drive EVs - we drive hybrids.

I totally disagree. If you were right, why is it called a PHEV and not a PH? All advertisement is about "the average daily commute is less than so many miles, so well within EV range for most people". This is what the Dutch Mitsubishi site says (according to Google Translate):

The innovative Plug-in Hybrid EV system is particularly eco-efficient. For example, you will be carefree with fuel consumption and CO₂ emissions of zero and enjoy the incredible peace during full electric driving. Or opt for hybrid driving when you want to cover longer distances, with low emissions and an impressive fuel efficiency of 1.7 liters / 100 km on average.

Maybe, you are kinda right, as a result of a poor implementation. But that is clearly not how it was supposed to be.

 

[maby]

We don't drive EVs - we drive hybrids.

I totally disagree. If you were right, why is it called a PHEV and not a PH? All advertisement is about "the average daily commute is less than so many miles, so well within EV range for most people". This is what the Dutch Mitsubishi site says (according to Google Translate):

The innovative Plug-in Hybrid EV system is particularly eco-efficient. For example, you will be carefree with fuel consumption and CO₂ emissions of zero and enjoy the incredible peace during full electric driving. Or opt for hybrid driving when you want to cover longer distances, with low emissions and an impressive fuel efficiency of 1.7 liters / 100 km on average.

Maybe, you are kinda right, as a result of a poor implementation. But that is clearly not how it was supposed to be.

The emphasis of the advertising seems to have changed over the last few years - in Britain, at least. When it first launched over here, I remember the TV adverts referring explicitly to it as a "plugin hybrid electric vehicle" - now they just seem to describe it as a "plugin hybrid SUV".

 

[elm70]

Back to Outlander PHEV battery degradation I just took my (by now) wife's car for a spin, and found that the engine kicks in when power demand is about 40 kW, even when increasing power demand very, very slowly. At max throttle, combined output of the E-motors is about 104 - 105 kW, where it IMHO should be 120 kW. I know this from monitoring RPM and Torque of both E-motors. But also, the needle does not go as far in the white as it did before (kind a up to the 2:30PM position, rather than up to the 3:15PM position) So, like it said before, it is not just energy that ids affected, but also power. Has a big impact on drivability, as even within the city limits, it is difficult to drive pure EV.

I'm bit confused about how many Outlander PHEV you own ... but I guess you are not any more a daily driver of Outlander PHEV

The info above is very scaring for me ... it is looking like that not only your battery degradation in capacity has been "massive" .. but as well the battery IR in your car is huge

I guess there is some logic in the car that if a cell in the battery goes below X volt (independently by the load) .. then the ICE need to kick in for support the over-discharge of the battery

It will be interesting if you could monitor how much your battery sink for each cell under load ...

On mine I manage to see some cells down to bit less then 3.50v ... without the ICE to kick in.

PS: Let me explain "scaring" ... I believe what is happening to your PHEV is what is going to happen to all of us in some years from now ... question is only when

PPS: Actually our PHEV it will not be even a hybrid car .. it will be just a "handicapped" hybrid with very limited EV capability ...

 

[elm70]

... This is important: Chemical cells lose capacity sitting on the shelf in the dining room. Literally. That's where I hand made battery packs and I still have 50 cylindrical LiFePO4 cells in boxes in my house that I keep for my projects and for any warranty replacements. They started as 11Ah cells 6 years ago. I change them, discharge them to 50% for storage every 2 years. They're down to about 9Ah now. There's nothing Mitsubishi can do to stop cells from losing capacity. Entropy's a real thing. That's all I'm trying to communicate.

We don't drive EVs - we drive hybrids. Use shore power to pre-heat or pre-cool the battery. Use petrol. The car MUST use petrol - we're going to burn it in regular use, or we're going to burn it when the computer requires it to keep the fuel from destroying the pumps and injectors. Use some of the energy we have to use anyway to 'baby' the lithium battery. That's my plan, anyway.

Honestly ... I can't be as sure as you are ...

Sure every battery de gradate with time even unused ... nothing is for ever .. not even a block of cement will be a block of cement forever ...

Still I believe some batteries have been designed for having longer life then other ... there a too many type of lithium batteries , so I don't even want to follow which is better in which condition ...

I know I have lithium battery which I acquired back in 2001 for RC hobby .. one of them from 2006 I'm still using as replacement of a lead acid battery on my "home" tractor (cutting grass "by hand" is too boring) , and still this battery which is charged only before usage and sitting at 3.75v or 3.80v for the rest of the time .. is looking to do as good as on day one in 2006 (but check 10% in lost battery capacity or increase IR .. would need proper testing .. it is not seen in normal usage)

Anyhow ... based on my "random" experience as lithium battery user in RC model (mainly air plane and drones) ... I see my set of battery, some even more then 10y old ... have different behaviour based on battery type/brand ... I have mainly Lithium Polymer battery, but as well I have Li-Ion and few Li-Fe

In the past I did not know (possibly nobody did) how to properly store lithium battery ... and some I did store fully charged for years .. and these .. are having mainly a huge IR ... but capacity wise are still in decent shape after more then 10 years ...

Anyhow ... I'm not sure how temperature management is relevant for battery ... all I know is that over 60deg the Lithium battery is compromised ... even worst is to charge a battery that is "hot" ... while I'm not sure there is any arm to use a battery in very low temperature ... our PHEV does not really have a AC system for cooling the battery .. I guess it is just a fan ... but I could be wrong about it ... in my experience I did notice while drive on motorway in a hot summer day .. there was some battery module very hot (~35deg or a bit more) ..and some more "fresh" like 25deg ...

 

[anko]

The emphasis of the advertising seems to have changed over the last few years - in Britain, at least. When it first launched over here, I remember the TV adverts referring explicitly to it as a "plugin hybrid electric vehicle" - now they just seem to describe it as a "plugin hybrid SUV".

But they didn't bother changing the name? From the UK website:

COMMUTE FOR PENNIES A DAY
Capable of up to 33 miles in EV mode, the average commute can be driven solely on electricity, reducing the cost to you and the environment as well as producing combined emissions of only 41 CO2 g/km.

 

[anko]

I'm bit confused about how many Outlander PHEV you own ... but I guess you are not any more a daily driver of Outlander PHEV

I still own just one. But my wife drives it, since I have taken delivery of an Ampera e on Janruary 3rd. Yesterday, was my first time back in the PHEV.

The info above is very scaring for me ... it is looking like that not only your battery degradation in capacity has been "massive" .. but as well the battery IR in your car is huge

It doesn't release more than 40 kW. Does not necessarily mean it is not capable of releasing more than 40 kW. Maybe it is just the PHEV ECU setting new upper boundaries to protect the battery from further degradation?

IR is still reported as 1.5M. As it always has.

 

[jaapv]

Driving a completely different type car for a while can completely skew your recollection of "how it was".

 

[MikkB]

One example of how to abuse a battery of any type: Start with an extremely cold battery pack, don't pre-heat or allow the ICE to run, then drive 20km to work. The poor battery has very high Ri, the chemical reactions are slow, and much of the energy liberated in the cell is converted to heat. Pre-heating or pre-cooling is a battery lifesaver.

Hi AndyH,

I'm struggling to keep up with the technical discussion here, but I'm interested in this comment in the context of the various discussions around how to prevent the ICE from starting up on cold days (not sure if UK cold days qualify as 'cold'). My questions are, if you are able to answer them;

Does the PHEV have battery warming capability, and is this part of why the ICE will sometimes run on startup?
Does an electric 'pre-heat' warm the battery as well as the cabin/windscreen?
How cold does it need to be for battery warming to take place/be required?

Many thanks.

 

[elm70]

The info above is very scaring for me ... it is looking like that not only your battery degradation in capacity has been "massive" .. but as well the battery IR in your car is huge

It doesn't release more than 40 kW. Does not necessarily mean it is not capable of releasing more than 40 kW. Maybe it is just the PHEV ECU setting new upper boundaries to protect the battery from further degradation?

IR is still reported as 1.5M. As it always has.

Reported IR most probably is an hard coded value or similar .. so possibly the ECU does not really use this.

Speaking of 40kw , or 60kw ... I remember Vtech told us that he can configure / reconfigure the 60kw limit to any other limit ... (he did show on YouTube a 70kw acceleration and he also mention 110kw was possible too)

Did your VTech box mess with this value ? Or did the PHEV firmware decided based on battery condition to change this parameter ?

For me it would make sense to limit the power if the lowest voltage in any cell in the battery is below 3.30v (or whatever configurable value) .. but ... possibly Japanese Engineers may have opt for a different approach ... in which case it would be a mystery to know which condition does set the max power down from 60kw to 40kw

Anyhow ... personally .. I would check if the limit of 40kw happen only when battery is discharged or also when SOC is close to 100% .. but it is your car , and I'm already happy you shared this important information with us.