How to best protect your drive battery.

[Trex]

Hi everyone,

Ok, still seeing some people here worried about degradation of the drive battery and I am not just talking about any particular person. Hell even I think about it as I am at the moment dealing with Mitsubishi Australia to hopefully get mine replaced under warranty. But to me its not a worry just more of a hassle. I have to handle far bigger problems at work in my own business with far bigger costs involved. But I digress.

Now I would normally probably write this up over in the Technical section but I think this is probably the most visited section plus I did not want to get too technical. I just want to give some of my general observations.

But just to put it into perspective for people that do not know me my first PHEV is nearly 5 years old (build Feb 2014) bought early April as soon as they released it here.

Now lets get onto the topic. Now remember this is my general observations but with a bit of research and experience thrown in.

I have to get this out of the way first though. Batteries degrade no matter if you never use them and say you put them in a fridge (a common way to protect RC batteries from my experience.). Age will kill them eventually at this moment in time.

Now lets say you just wanted to treat the PHEV just like a Hybrid Electric Vehicle (HEV) as some here I think do ie very little EV mode. By treating the PHEV like this I think the drive battery will last longest unless we do not use it at all. I hope everyone agrees.

But there is more to it than that. What State Of Charge (SOC) would I leave it in. I would do like member maby and leave it at the top of the Charge or Save modes which is about 85% SOC or even higher. As soon as you press Save (or Charge) the SOC will drop down to about 85% from 100% and you should leave Save pressed.

Why I hear you say? Well I am glad you asked. Because at that level the PHEV is doing a number of things automatically to protect the battery. It reduces regen on the paddles (B1-B5) on my PHEV and reduces the On Off cycle that happens when the loads are light on the petrol engine dramatically from my tests. It basically puts the PHEV into a automatic reduced use of the battery mode. You will have excess charge to climb hills etc BUT your petrol motor will run more so you will be less efficient and you will probably have to change your brake pads more according to my tests.

Now lets say you still want to EV around town a bit ie use you battery sometimes. I would still leave it at the top of the Save mode of 85% SOC as much as possible out on the highway for the reasons stated above.

Now you will lose some SOC climbing big hills. Do not charge it at the top back to 85% (just leave Save pressed at the bottom) as you will not have anywhere to put back into the battery any regen on the way back down because we do not want to have any chance having brake problems. A battery's cost is not worth safety IMHO. Once back down you can go back to 85% SOC.

So that is basically it. I can bring in my tests or we have graphs etc to show from over in Technical to back up the statements I made above if you feel that necessary.

Also this is not something I would necessarily do but the option is there.

I hope maby does not mind me mentioning him here and hope he will get involved in this discussion. As well as others of course.

Ask those questions if you do not understand as sometimes I do NOT explain myself probably as good as I should especially when I am in a hurry to get my thoughts on "paper" as probably in this thread.

I also want to say this. IMHO worrying too much about problems is bad for your health. That include mental,physical and financial health ie I totally believe in not whinging about problems as much as possible and just get into finding ways to solve them as best you can. I just want to put that out there.

As well, please do not come into this discussion if you just want to put crap on Mitsubishi. I think it is a great car and it will not solve anything IMO.But constructive criticism is reasonable I think.

Regards Trex.

 

[STS134]

I think 85% is a bit high and high SoC for sustained periods of time can kill batteries especially in hot weather. I'd keep the batteries at exactly 3.92V/cell which is 7/16 bars on the gauge, or around 55-65% in PHEV Watchdog (on the display with the % SoC and either Ah or kWh next to it). In fact I was looking at how to replace my phone battery today and I found a Reddit page with someone commenting on how his or her Prius manages its batteries: https://www.reddit.com/r/GooglePixel/comments/7jl2v1/ubreakifix_og_pixel_battery_replacement/

"As a reference, I own a 1st Generation Prius from 2003. ~115,000 miles and 15yrs old.

15yrs and millions of charge cycles on the original drive battery.

When I monitor the battery state, and it's SOC (State of Charge), it rarely allows it to charge >~70% or allow it to be used and discharged below ~45%. (I may be off by 5-10%, but it was close to this. I never saw 80% full or 40% empty)

This along with the precise temperature monitoring per cell and fan to cool if too hot in the summer, I'm confident helps make these Metal Oxide batteries last 15yrs will millions of charge cycles.

If only we could do the same with phone batteries."

 

[ThudnBlundr]

Prius batteries were a totally different battery chemistry to our PHEV's Lithium batteries until fairly recently (except for the Prius PHEV), so it is pointless comparing them

 

[elm70]

Prius was using NiMh batteries ... which have way less energy density compared to Lithium batteries

NiMh can be stored in any charging condition as far as I know ... but from my old time racing 1:10 RC car and NiMh cells .. "expert" racers like to discharge the pack to 0.7v per cell (1.2v is the nominal voltage per cell) ... but racer were more keen on maximize the performance, not the longevity ... so discharge to 0.7V possibly was only for maximize the power while charging the cells just before the race

NiMh cells have problem on over discharge and bring these into reverse polarity .. discharge to 0V look like is not an issue
NiMh cells have problem on over charge .. since they will start to ventilate and lose capacity

 

[HHL]

You could also just drive the car like any other, charge it when you feel like it and generally not worry too much about the battery. That's what I do.

 

[elm70]

...

I have to get this out of the way first though. Batteries degrade no matter if you never use them and say you put them in a fridge (a common way to protect RC batteries from my experience.). Age will kill them eventually at this moment in time.
...

I think you like too much Mitsubishi/Outlander/PHEV for be objective in this subject.

Yes, everything with time is going to transform and "die" ... the question is how fast.

A car should be able to last at least 15 years ... ok Mitsubischi Australia decided that 10y is the life of their PHEV .. since they made a mistake on some Australian brochures , and they have been forced to define a precise life time for the Outlander PHEV

You are claiming since ages that SOH does not impact much on EV range ... but this is 100% false and wrong

For how it is designed this PHEV each drop in SOH does impact proportionally into the possible EV range.

80% of SOH, equal 80% of EV range compared to new.

Other thing that I find hard to accept ... it is to try to dis-inform people that the Mitsibishi PHEV batteries are worrying free
Even recent PHEV from 2017 shown a mayor drop of SOH even with less then 20.000km ... the WatchDog facebook page is full of people reporting very poor SOH , also from people with a new PHEV and few km done

With your car you are lucky due to the legal action done by somebody that believe in opposite way then you, and thanks to then and to the PR mistake of Mitsubishi, now everybody in Australia with an PHEV (sold at the time that the wrong information published) has granted 80% SOH for the 10y of the car life .. with free battery exchange from Mitsubishi

Other are not so lucky and have to fight for get battery replacement for battery that lost over 30% SOH
Other will have to pay with further car devaluation, since we have already reports of how badly the car behave when the battery is in very low SOH and with high IR

Finally ...

Since there is a big difference in SOH of our batteries ... yes ... how people handle the car and how people charge their own PHEV, has a huge impact on the battery life and battery SOH.

PS: People bought a PHEV with 50km EV range ... assuming it can do 40km in EV mode also 10y after the car was new ... people don't expect that once the SOH is too bad ... the car is more a normal hybrid then a PHEV

 

[elm70]

You could also just drive the car like any other, charge it when you feel like it and generally not worry too much about the battery. That's what I do.

Just an important note

If I make 1km in EV mode, with energy sources from my home electric network ... this km cost me 25% compared to 1km done with the energy coming from the petrol in the PHEV tank. It is a factor 4 .. which isn't that much irrelevant.

This without taking into account that when the PHEV run with the ICE on ... it does "consume" multiple components of the car, which otherwise they would be preserved

Lower is the SOH, and more expensive is the usage and the maintenance of the PHEV

 

[Sumpy]

I think people are worrying far too much about the battery in the PHEV.

I just drive and charge the car as is required and what fits around my life. The car is just a tool to get me and mine from A to B, and it does that reliably and comfortably (albeit with a wobbly gear knob :roll: ooer, steady!).

I don't have the watchdog app (stone him he's a luddite!) and I don't know exactly what state of health my battery is before, during or after a drive (too busy enjoying life with my family or listening to music or both (kids hate both :lol: )), It still takes about 5 hours to charge overnight on the provided charger that came with the car, so I am happy that the car still does 22 to 26 miles on EV alone. I look at the battery the same way that I have looked at every lead acid battery, brake pads/shoes and discs, tyres or wiper blades from all the cars I have owned before, it is a consumable item that has a certain life and will wear-out, degrade or generally stop working at some point.

If my EV range drops too much too quickly, then I will of course be back to the dealer to get it sorted, has anyone had a battery reduction of 50% or more?

I plan on keeping this car for a few more years yet, and if in another 5 years say my EV only range is in single figures then I will look into the feasibility of a replacement battery (hopefully solid state) or the option I am really hoping for is to change the car for a BEV depending on how the charging infrastructure has improved by then (looks like a battery upgrade in the PHEV then).

I really enjoy reading all the different views and information on this forum, but for me I try to enjoy every day to the fullest I can, and to be honest the battery in my car is not on my list of things to worry about.

 

[windymiller]

As advised to us by Mitsubishi, via the dealer, in response to our question about how to slow the rate of degradation;

[*]Always run the battery down to "empty" before recharging
[*]Always charge to completely full
[*]Never partially charge
[*]See if that helps

I have it on an email from them somewhere.

 

[ChrisMiller]

I just drive and charge the car as is required and what fits around my life. The car is just a tool to get me and mine from A to B, and it does that reliably and comfortably

Amen, brother. Look, I'm a geek, I like to play with the flappy paddles and even the save/charge buttons, but I don't expect to make more than a few percent difference* to either fuel consumption or battery life. It's certainly not something to agonise about.

* and I'm not even sure whether positive or negative

 

[STS134]

As advised to us by Mitsubishi, via the dealer, in response to our question about how to slow the rate of degradation;

[*]Always run the battery down to "empty" before recharging
[*]Always charge to completely full
[*]Never partially charge
[*]See if that helps

I have it on an email from them somewhere.

That's basically everything you DO NOT want to do if you want to prolong the life of a lithium-ion battery! You get the longest life from a li-ion battery if you use only a very narrow portion of its total SoC range. See Table 2. https://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries

 

[Trex]

I think 85% is a bit high ...............

You have to take it into context of why I said it IMO which was "It basically puts the PHEV into a automatic reduced use of the battery mode".

Would you agree using the battery less decreases degradation?

 

[Trex]

Prius batteries were a totally different battery chemistry to our PHEV's Lithium batteries until fairly recently (except for the Prius PHEV), so it is pointless comparing them

I think I could go either way on this statement ie I see both sides of the argument. So I will stay out of it.

 

[HHL]

As advised to us by Mitsubishi, via the dealer, in response to our question about how to slow the rate of degradation;

[*]Always run the battery down to "empty" before recharging
[*]Always charge to completely full
[*]Never partially charge
[*]See if that helps

I have it on an email from them somewhere.

I think they just made that up......

Or copied and pasted from an old NiCad battery powered remote race car instruction sheet....

 

[Trex]

You could also just drive the car like any other, charge it when you feel like it and generally not worry too much about the battery. That's what I do.

I agree HHL except I can hardly ever get to drive it. Oh well, back to the Ford Courier ute for me. I know my place.

 

[STS134]

I think 85% is a bit high ...............

You have to take it into context of why I said it IMO which was "It basically puts the PHEV into a automatic reduced use of the battery mode".

Would you agree using the battery less decreases degradation?

Sure. Putting the voltage at 3.92 V/cell and storing the entire vehicle in a refrigerated garage and never driving it, decreases degradation even further though.

But more seriously, I think particularly in hot weather, the degradation caused by keeping the battery at such a high SoC for most of the time would probably outweigh the degradation caused by increased regen current. By the time Save mode kicks in, it's doing almost full regen.

 

[windymiller]

That's basically everything you DO NOT want to do if you want to prolong the life of a lithium-ion battery! You get the longest life from a li-ion battery if you use only a very narrow portion of its total SoC range. See Table 2. https://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries

At the risk of incurring the wrath of the OP, and in particular the second last sentence of the top post in this thread.....

Thats what we have in an email. I can only take it as it is presented. Has it made any difference to the rate of degradation as reported through the OBDII port? No. Has it turned the vehicles into gas guzzlers? Yes.

I guess if they are guzzling gas, they are not using the battery (so much), and if the battery is not being used so much, there will be less degradation, so thats perhaps MM's logic.

But, as MM are God, I am inclined to believe all they say.

 

[Trex]

:?

...

I have to get this out of the way first though. Batteries degrade no matter if you never use them and say you put them in a fridge (a common way to protect RC batteries from my experience.). Age will kill them eventually at this moment in time.
...

I think you like too much Mitsubishi/Outlander/PHEV for be objective in this subject.

So do I have to I hate Mitsi or the PHEV or both to be objective about batteries. Or is it somewhere in the middle? :?

A car should be able to last at least 15 years ... ok Mitsubischi Australia decided that 10y is the life of their PHEV .. since they made a mistake on some Australian brochures , and they have been forced to define a precise life time for the Outlander PHEV

Just what the hell does Mitsubishi Australia decisions have to do with you? How do they affect you? Are you moving here? :? Sure you can have a opinion of what happens here but with you no "IMO" or "I think" just a smart arse comment or trolling IMHO.

I think 10yrs is a reasonable classification for a lifetime of a vehicle in these modern times and I live here in Australia where this affects me.

You are claiming since ages that SOH does not impact much on EV range ... but this is 100% false and wrong

Ok, now you are going to lie about me for trolling purposes. May have to get the Mods involved I think.

On this forum I have done 7 range test that I have posted here individually. I have had to put up with people saying its not necessary to do but I keep doing them and I keep posting them.

Here is a summary of the 7 individual posts you LYING TROLL.

I did another range test on my oldest PHEV.

I do this test by driving with a fully charged drive battery early morning, (light traffic so few red lights) with no heating or air conditioner along the same route (same speed) after resetting the odometer and note when the petrol motor starts and goes into hybrid mode. The results of the tests are:

1. 52.5kms Just after buying Phev early April 2014
2. 52.9kms 6ths months later ie October 2014
3. 51.8kms April 2015 Now this test had notable more traffic (some big area championships soccer games) ie stopped at traffic lights more than last 2
4. 53.0kms October 2015
5. 48.2kms January 2017 Battery condition was 86.05% according to EVBatmon.
6. 45.1kms February 2018 Battery condition was 78.68% according to EVBatmon. Geolander 4wd tyres fitted before this test.
7. 38.8kms December 2018 Battery condition was 72.11% according to EVBatmon.

Pretty sure I was saying there that degradation is affecting range. :roll:

 

[Trex]

Other thing that I find hard to accept ... it is to try to dis-inform people that the Mitsibishi PHEV batteries are worrying free
Even recent PHEV from 2017 shown a mayor drop of SOH even with less then 20.000km ... the WatchDog facebook page is full of people reporting very poor SOH , also from people with a new PHEV and few km done

So you are saying is that I am deliberately supply false information (disinform) about PHEV drive batteries? Where TROLL?

As for worrying about the drive battery what does it do? Whinging here or on youtube is not going fix it for me. Get to your dealer and start the process rolling as well as contacting your importer which for me is Mitsubishi Australia.

With your car you are lucky due to the legal action done by somebody that believe in opposite way then you, and thanks to then ...............

Who is somebody? :?

From my dealings with Mitsubishi Australia it is a case by case basis. Now I have been working with them for about a year now and they are treating me very helpfully so far.

Will they give a new battery? Not sure yet. Some software changes, so I can use the reserve at the bottom of the drive battery just sitting there could be good enough for me.

Now that is as far as I will go with this TROLL.

Now where are the Mods?

 

[Trex]

I think people are worrying far too much about the battery in the PHEV.

I just drive and charge the car as is required and what fits around my life. The car is just a tool to get me and mine from A to B, and it does that reliably and comfortably (albeit with a wobbly gear knob :roll: ooer, steady!).

I don't have the watchdog app (stone him he's a luddite!) and I don't know exactly what state of health my battery is before, during or after a drive (too busy enjoying life with my family or listening to music or both (kids hate both :lol: )), It still takes about 5 hours to charge overnight on the provided charger that came with the car, so I am happy that the car still does 22 to 26 miles on EV alone. I look at the battery the same way that I have looked at every lead acid battery, brake pads/shoes and discs, tyres or wiper blades from all the cars I have owned before, it is a consumable item that has a certain life and will wear-out, degrade or generally stop working at some point.

If my EV range drops too much too quickly, then I will of course be back to the dealer to get it sorted, has anyone had a battery reduction of 50% or more?

I plan on keeping this car for a few more years yet, and if in another 5 years say my EV only range is in single figures then I will look into the feasibility of a replacement battery (hopefully solid state) or the option I am really hoping for is to change the car for a BEV depending on how the charging infrastructure has improved by then (looks like a battery upgrade in the PHEV then).

I really enjoy reading all the different views and information on this forum, but for me I try to enjoy every day to the fullest I can, and to be honest the battery in my car is not on my list of things to worry about.

+1. I just want get to drive the bloody thing. :roll: