Battery Degradation Issues: I bet you wil suffer from them

Mitsubishi Outlander PHEV Forum

Help Support Mitsubishi Outlander PHEV Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

user 457

Member
Joined
Sep 2, 2014
Messages
6
I am in Australia. My PHEV drive battery has been measured at 71.1% SoH with consequential reduced EV range. The car is under 5 years old and is under 65,000KM. I have been battling with Mitsubishi Australia to get it resolved since April. A few tests, a battery BMU reset and it is all still dropping. Very disappointed. I know of 11 other aussies that have a similar problem. Mitsubishi denies liability and is very slow to respond. In Australia we don’t have the warranty other countries have on the battery, but we do have strong consumer laws and a promise from Mitsubishi in their sales material that promises the battery won’t drop below 80% SoH for the LIFE OF THE CAR. We have made quite a bit of progress with them but are not there yet because we think they are trying to hide this issue. We are considering a class action and are getting a couple of consumer advocate agencies involved. If you live in Aus and want to join up message me and I will let you know how to join. If you are elsewhere I suggest you get the PHEVWatchdog app and an OBD and measure your battery if your range has dropped. We think that Mitsubishi has a worldwide problem but they are trying to keep it quiet. Contact me for more information and beware. See graph of my SoH below: View attachment 8E55FFD5-1331-4D90-8EE0-DCEBC271DEEF.jpeg
 
What was that jump to 100% from in April?

What % of your distance traveled is EV and what % is ICE?

What is your average DoD, and what voltage do you typically charge to?
 
STS134 said:
What was that jump to 100% from in April?

What % of your distance traveled is EV and what % is ICE?

What is your average DoD, and what voltage do you typically charge to?

The jump in 100% in April was because when I took it into the service centre they ran a routine on it which resets the battery management unit (the BMU). It is designed to only be run when a new battery pack is put in so they shouldn’t have run it. It basically tells the car that the battery is new and the capacity (SoH) is as new. You can see the rapid decline as the BMU learns pretty quickly that the battery isn’t what it thought it was and adjusts it as fast as it can. You can see another sharp drop in August from around 84 to 73. That’s where I took it into Mitsubishi again and they ran the correct battery testing procedure - the DBCAM procedure. That flattens the battery entirely, charges and smooths the cell voltages then uses that to measure the actual capacity. That’s when they proved with their own measurements it was around 73%. I expected the pace of decline to slow from that point but it has kept dropping quite rapidly.

% of distance travelled EV os reasonably high as we mostly use it for commuting around town and charge it every night but that’s the purpose of buying a plugin hybrid in the first place. We go on long trips too.

As for DoD - I’m not sure how to measure that but it is fairly common to get the battery to empty as the car’s dashboard says (but I think it keeps 20-30% in reserve). When I charge it - except very occasionally I use the charger that came with the car. The timer is set to start charging at around midnight so the batteries are cool and it is ready for the morning with a full charge.

None of the charging or use regime is anything other than the manual says - so far as it gives guidance, and I am not filling it with extreme charges, leaving it empty or full. Just using the car.
 
pscampbe said:
STS134 said:
What was that jump to 100% from in April?

What % of your distance traveled is EV and what % is ICE?

What is your average DoD, and what voltage do you typically charge to?

The jump in 100% in April was because when I took it into the service centre they ran a routine on it which resets the battery management unit (the BMU). It is designed to only be run when a new battery pack is put in so they shouldn’t have run it. It basically tells the car that the battery is new and the capacity (SoH) is as new. You can see the rapid decline as the BMU learns pretty quickly that the battery isn’t what it thought it was and adjusts it as fast as it can. You can see another sharp drop in August from around 84 to 73. That’s where I took it into Mitsubishi again and they ran the correct battery testing procedure - the DBCAM procedure. That flattens the battery entirely, charges and smooths the cell voltages then uses that to measure the actual capacity. That’s when they proved with their own measurements it was around 73%. I expected the pace of decline to slow from that point but it has kept dropping quite rapidly.

% of distance travelled EV os reasonably high as we mostly use it for commuting around town and charge it every night but that’s the purpose of buying a plugin hybrid in the first place. We go on long trips too.

As for DoD - I’m not sure how to measure that but it is fairly common to get the battery to empty as the car’s dashboard says (but I think it keeps 20-30% in reserve). When I charge it - except very occasionally I use the charger that came with the car. The timer is set to start charging at around midnight so the batteries are cool and it is ready for the morning with a full charge.

None of the charging or use regime is anything other than the manual says - so far as it gives guidance, and I am not filling it with extreme charges, leaving it empty or full. Just using the car.

For DoD, you can take the total number of kWh put into the battery and divide it by the total number of charges, then calculate the DoD. For example, for me, for September, I've taken 152 kWh of total energy in 52 sessions. That's 2.92 kWh/session or an average DoD of around 25%. I would estimate that about 40% of my miles are ICE miles and the remaining 60% are EV miles. On average, I charge to 12/16 bars or around 4.03-4.05V/cell.

Another way you can look at this is that I'm doing around 13-15 cycles/month (12 kWh is the battery capacity and so each time you take in 12 kWh, that's one cycle), average DoD of 25%, and charging to around 70-80% on average.

Now lithium batteries usually are good for around 600 cycles before the SoH falls to 80%, if discharged to 0% and charged to 100% (4.20 V/cell) repeatedly. Only charging to 4.10 V/cell, as the Outlander does, approximately doubles the number of cycles. Furthermore the BMU only allows discharge to around 30%, not to 0%, which should increase the battery life by a further 1.5x or so (only discharging to 50% would be around 2x number of cycles). In any case, this is probably around 1500-2000 cycles. You have 65000 km on the car, and if you did 100% of that distance in EV mode, that would be 65000km/35km = 1857 cycles. That SoH does seem a bit on the low side of what I'd expect, but it's still in the general range of expectation if you really have put the battery through 1800 cycles. The 80% SoH promise over the life of the car is ridiculous though. In a Tesla, sure. With > 500 km of range on a charge, 2000 cycles is 1000000 km. And almost nobody is going to do 100% DoD on those batteries daily, nor are they going to charge to 100% except for maybe a few times a year when they are doing a roadtrip. Then there is the matter of pulling charge out of the battery at > 1C, which shortens battery life. I've noticed that when starting out from a stop, the Outlander will easily pull 30-40 kW from the battery. That's a discharge rate of 3C, although thankfully it's only for a short period of time. But to do the same thing to a Tesla, you'd have to launch the thing in ludicrous mode (which draws around 450 kW) EVERY SINGLE TIME. Most of the time the batteries are only supplying a current of less than 0.5C.
 
I've read (not a Tesla owner) that Tesla's car/system keeps track of the number of times you use a supercharger and can block further use if it calculates that it may damage the battery (this can only happen under pretty extreme mileage rates). Since recharging an 'empty' P100D from a domestic supply would take a couple of days, I'm not sure what happens after that.
 
ChrisMiller said:
I've read (not a Tesla owner) that Tesla's car/system keeps track of the number of times you use a supercharger and can block further use if it calculates that it may damage the battery (this can only happen under pretty extreme mileage rates). Since recharging an 'empty' P100D from a domestic supply would take a couple of days, I'm not sure what happens after that.
I haven't seen any evidence of that. https://electrek.co/2018/07/17/tesla-model-s-holds-up-400000-miles-3-years/ Supercharging frequently does wear down the battery though. Battery #1 on that Tesla was replaced at 194000 miles (312000 km), after only 6% degradation, due to severe cell imbalance. Pack #2 was replaced at 324000 miles (521000 km, difference of 118000 mi or 194000 km), with a degradation of 22%.

Teslas will, however, warn you if you tell them to charge the batteries to 100%, to not do it frequently or you are going to kill the batteries.

Bottom line though, PHEVs, with their undersized batteries, weren't meant to be driven around in 100% EV mode on the freeways all the time. If you're drawing current at 2-3C for long periods of time, you're going to kill the battery quickly. If you're going through 2+ cycles per day, you're going to kill the battery quickly. That's why I always use Save mode at speeds of > 50 mph/80 kmph, irrespective of how much charge I left left in the battery. Why Mitsubishi hasn't provided an option to limit the charge level, OR programmed the ECU to always kick in the ICE when the speed goes over 50 mph unless you select EV priority mode, I'm not sure. This would mean that I wouldn't have to press so many damn buttons all the time.
 
My PHEV is almost 5y old, and has almost 140k km.

Per the DOG , the SOH is almost 89.5% or 34.0Ah

10% lost in 5y is "ok" ... possibly when my car will be 10y old, battery should still be around 80% SOH

I think weather, or better hot weather has a huge impact on battery life ... when it is parked and unused, especially if left with high SOC ... there is no defense against the hot weather .. and above 30C especially at high SOC .. battery degradate very fast

Still ... some PHEV look like have been sent out with weak battery ... like the PHEV from Anko, which lost 10% SOH in less then 1 year usage
 
STS134 said:
Bottom line though, PHEVs, with their undersized batteries, weren't meant to be driven around in 100% EV mode on the freeways all the time.
Apparently Mitsubishi does not agree with you. Otherwise they have allowed us to drive 125 km/h in EV mode.
 
elm70 said:
My PHEV is almost 5y old, and has almost 140k km.

Per the DOG , the SOH is almost 89.5% or 34.0Ah

10% lost in 5y is "ok" ... possibly when my car will be 10y old, battery should still be around 80% SOH

I think weather, or better hot weather has a huge impact on battery life ... when it is parked and unused, especially if left with high SOC ... there is no defense against the hot weather .. and above 30C especially at high SOC .. battery degradate very fast

Still ... some PHEV look like have been sent out with weak battery ... like the PHEV from Anko, which lost 10% SOH in less then 1 year usage
I don't think Anko's weather is hotter than Poland.
 
anko said:
STS134 said:
Bottom line though, PHEVs, with their undersized batteries, weren't meant to be driven around in 100% EV mode on the freeways all the time.
Apparently Mitsubishi does not agree with you. Otherwise they have allowed us to drive 125 km/h in EV mode.

Just because a manufacturer allows for something, doesn't mean it's good for the vehicle. Manufacturer's design and allow for launch control too, for the sake of impressive 0-60 times, but it also reduces vehicle life fast if done often.
 
Thanks for your informative posts. I don't know how often the car has been charged as I think I lost that in the BMU reset. I will look around the watchdog app and see, but I bet it is 1800+. That's the trouble. The way the car was sold to me gave no indication of the complexity of managing the Lithium batteries life. I understand that my phone's battery degrades and assumed that the car would do the same, but was assured by Mitsubishi's sales people and their material that they had thought of everything. The 30% bottom buffer and the top 5-10% buffer gave me confidence. Looking at these posts and comparing it to a Tesla it couldn't be more different. Given the tiny comparative capacity of the PHEV to the Tesla, day to day driving and charging, the power taken out of the battery to drive normally etc is all huge compared to the battery size - unlike a Tesla. Know I know this I think it is quite significant. Pity I wasn't an electrical engineer/battery expert because then I wouldn't have bought the car.

Check out this lifted from the FAQ's in the Australian sales material. Interestingly, some time this year, they removed the last statement around the 80% - so they must think it was stupid too. Not stupid enough to sell cars, but stupid if it comes back to haunt them. I am a bit frustrated that they aren't engaging with me properly, just wait a few weeks for each formal, confidential, no liability accepted exchange. Like pulling teeth - also for the others in the same boat as me. I am glad Australia has strong consumer laws, however would like to hope I don't have to challenge them significantly.

Thanks again for your advice and context. I will keep this thread updated as I progress (if I don't end up bound by some sort of confidentiality agreement).
View attachment Battery80PCTFAQ.JPG
 
jaapv said:
I don't think Anko's weather is hotter than Poland.

Maybe Anko's PHEV likes to spend summer in some tropical island :cool:

Anyhow ... what I did want to said is that PHEV battery get degradated faster in hot weather ... but as well, we have evidence that some PHEV battery pack did born "unfortunate" .. else I would not explain why Anko's battery lost 10% in less then 1y time from new.
 
I think it might be that your car was driven like a normal hybrid during the first part of its life and not plug-charged once.
 
jaapv said:
I think it might be that your car was driven like a normal hybrid during the first part of its life and not plug-charged once.

I don't know

For sure my car, when used by its first owner in NL , it had a some time which was not charged since the charger was broken.
As well, this guy was also doing a lot of km .. 120k in just 2 years. so I guess to charge or not the car was not making much of the difference.

Still .. in the last 2 years, it has been almost daily charged

My PHEV now as almost 90% SOH ... something that some people lost from new in less then 1y

Both mine and Anko are '13 PHEV models .. so the early PHEV in EU/NL

So .... I tent to believe that some PHEV has been shipped out from with a B quality pack, and some with a A quality pack ... so ... I don't know what could be the % of A and B pack .. but for some graph that some application owner are doing over battery degradation, I'm not the only one with a 5y old PHEV and around 10% decline in SOH ...
 
OP lives in Australia so likely to be hotter summers than in most of Europe - even with the cooling in the PHEV, it may be the same problem that the Leaf had in the US desert states. Even if daily re-charging to full has brought up the maximum effect life earlier than expected perhaps a similar class action is the way forward, if the car was never suitable for the market.

BTW what is current range? With the figures given the OP has used very little petrol is he not "in pocket" despite the degradation?
 
Range ?

Guessometer does not provide any sense in my car (it can be a very high number even above 54km range, but it will collapse quickly while driving, even while driving slowly)

My record so far has been around 47km in EV mode .. mainly driving at around 80km/h on motorway

The driving pattern also can impact the range ... if I make 10km .. and then I stop over 2h .. car wrongly believe SOC has gone up, and I can do in theory further 35km per the guessometer ... if I make 20km trip, and I stop, the car will believe SOC has gone down while parked .. and I have less EV range

Anyhow ... with my normal driving I'm able to do 33km up to 40km .. with a 90% SOH

While my battery is getting worst, my driving style got adapted .. so I am more efficient .. so I don't see much difference compared to 2y ago .. when I had over 96% SOH in my PHEV

PS: About class action ... I think you are right .. but it is country specific ... so people from Australia should try .. but hopefully Mitsubishi can find a solution before go in the courts ... I think 70% SOH guaranty for 160km or 8y is relative fair ... but I agree that in some markets they may have give the "wrong" advertise by promising 80% SOH guaranty ...
 
Woodman411 said:
anko said:
STS134 said:
Bottom line though, PHEVs, with their undersized batteries, weren't meant to be driven around in 100% EV mode on the freeways all the time.
Apparently Mitsubishi does not agree with you. Otherwise they have allowed us to drive 125 km/h in EV mode.

Just because a manufacturer allows for something, doesn't mean it's good for the vehicle. Manufacturer's design and allow for launch control too, for the sake of impressive 0-60 times, but it also reduces vehicle life fast if done often.
Come on. You cannot compare launch control with allowing the car to do its own thing while driving along with other traffic on the motorway.
 
anko said:
Come on. You cannot compare launch control with allowing the car to do its own thing while driving along with other traffic on the motorway.

Just pointing out that manufacturer allowing does not equal good-for-vehicle. The problem, as STS has pointed out, is that driving at motorway speeds in EV mode is at the top limit for the Outlander's batteries, incurring high discharge rate. Just like driving at the top speed limit of the ICE engine is not good for the engine (same idea as high-rpm in ICE to high-discharge in batteries).
 
I know exactly what he is claiming. But it is a bit weird to state that the car was not meant to be driven in EV mode at motorway speeds. As EV mode is the default mode at motorway speeds (and EV mode even occurs when the car is operating in hybrid mode at speeds up to 125 km/h), this is almost the same as stating the car was not meant to be driven at motorway speeds.

What car requires you to push additional buttons in order to stay within intended use?
 
anko said:
I know exactly what he is claiming. But it is a bit weird to state that the car was not meant to be driven in EV mode at motorway speeds. As EV mode is the default mode at motorway speeds (and EV mode even occurs when the car is operating in hybrid mode at speeds up to 125 km/h), this is almost the same as stating the car was not meant to be driven at motorway speeds.

What car requires you to push additional buttons in order to stay within intended use?

Fact 1: battery drive top speed is 125/135 kph (2.0L/2.4L)
Fact 2: driving in EV mode anywhere near the battery drive top speed will drain the battery very quickly (meaning high discharge rate)
Fact 3: high discharge rate = lower battery longevity: https://pdfs.semanticscholar.org/810a/ee30e307fd5b0ffe4768f3461f579aafeac6.pdf

It is not a question of what the car was meant for. It's a question of whether it is good for the battery long term.
 
Back
Top