Battery life span will not be affected by PHEV mode selection?

[Woon Chung]

After I bought Outlander PHEV, I was always curious about why there is a charging mode. I owned Hybrid before this car and it does not have charging mode, because computer controls charging sequence automatically. After a short period of searching here and there, including other issues, too, to learn about my new(not brand new, but 2022) PHEV information. So far, I concluded that this has less relation for driving efficiency, but much related in "EMERGENCY CASE". like extra power source during camping and short time of grid power outage. One example of the evidence is 120V 1500w outlet in GT model in North America. The behind story of this is that 2011 Tsunami in Japan. This disaster made Mitsubishi to install 3000w level inverter inside the car, even though it limits to 1500w by its own On/Off switch.

There are some different opinions in the forum for money saving by using charging mode during driving. In here, I would like to add that most general information of Lithium Ion Battery character of Life. This battery has limited life span according to full charging frequency. Thus, lot of devices which using Lithium Ion battery apply safety circuit to prevent full charge, at the same time apply safety circuit to prevent full discharge. to extend its life. We have to talk about Mitsubishi Drive Battery Life span, too, considering frequent use of charge mode.

In the old time, Internal Combustion engine lasts a couple of decade without any big issues when we maintain properly, even more than that. Lots of Volvo and Forester is still running on the street. Most popular reason to change the car is old fashion or lots of other fancy models in the market. But when it comes to EV, most of the car owner want to sell his or her car not to face the case of replacing battery. The cost of replacing battery is more expensive than the cost of replacing the ICE motor. The battery technology is advancing day by day, but still long way to go.

Could it be good to battery if I do not charge at all as if it drives like pure Hybrid car?
Could it be better for battery if I charge only 80% at wall charger?
Could it be no problem for battery life span if I charge 100% every night?
Could it be safe to battery if I use charge mode all the time during driving?

Please give me your idea regarding battery life span by how we use drive mode in OHEV

 

[AndyInOz]

Using charge mode will slightly decrease the life of the battery, but it shuts off at 80% of user-space charge. Charge mode is equivalent to a fast charge.

The batteries have a fixed amount of charge/discharge cycles, but...

... running the battery to zero before recharging it, makes the battery wear out faster.

Mostly this is managed by the car's software.

A daily recharge is best for lithium polymer batteries, and there is no need to discharge to zero before doing it.

This is the opposite to NiCad batteries, where daily charging reduces the capability of the battery, and frequent discharge to zero is recommended.

 

[Woon Chung]

Using charge mode will slightly decrease the life of the battery, but it shuts off at 80% of user-space charge. Charge mode is equivalent to a fast charge.

The batteries have a fixed amount of charge/discharge cycles, but...

... running the battery to zero before recharging it, makes the battery wear out faster.

Mostly this is managed by the car's software.

A daily recharge is best for lithium polymer batteries, and there is no need to discharge to zero before doing it.

This is the opposite to NiCad batteries, where daily charging reduces the capability of the battery, and frequent discharge to zero is recommended.

What a great advise.

I just started to run charge mode instead charging from AC outlet because I have to consume a certain quantity to maintain sound IDE because I drive short distance in a whole year. I have to quit this plan to save battery life.

I am really in dilemma as much as I search this forum. Every posts are not match with my case exactly.

As of today, I concluded that I have to consume 5 gal of gas every 90 days in order to maintain the regular performance of ICE. If I calculate this gasoline consuming, I have to run 150 miles with ICE running with gas engine for a quarter year, assuming Pure gas mileage of ICE only is 26 miles per gallon(11km/Liter), and 100mile from battery. This result that I have a chance 5 times of EV only mode for 90 days. Am I going right?. Am I wishy-washy guy?

I was expecting running whole year with EV mode. but it became a castle on the sand beach all of a sudden

 

[mellobob]

Using charge mode will slightly decrease the life of the battery, but it shuts off at 80% of user-space charge. Charge mode is equivalent to a fast charge.

The batteries have a fixed amount of charge/discharge cycles, but...

... running the battery to zero before recharging it, makes the battery wear out faster.

Mostly this is managed by the car's software.

A daily recharge is best for lithium polymer batteries, and there is no need to discharge to zero before doing it.

This is the opposite to NiCad batteries, where daily charging reduces the capability of the battery, and frequent discharge to zero is recommended.

And, like charging, decreasing the juice in the battery to 0 is not practically possible. I suppose if you have no gasoline and decide to go uphill at high speed ... but, otherwise when it goes to zero you still have 10 to 20% left and the ICE will be charging it (if you want it to or not).

 

[Woon Chung]

Using charge mode will slightly decrease the life of the battery, but it shuts off at 80% of user-space charge. Charge mode is equivalent to a fast charge.

The batteries have a fixed amount of charge/discharge cycles, but...

... running the battery to zero before recharging it, makes the battery wear out faster.

Mostly this is managed by the car's software.

A daily recharge is best for lithium polymer batteries, and there is no need to discharge to zero before doing it.

This is the opposite to NiCad batteries, where daily charging reduces the capability of the battery, and frequent discharge to zero is recommended.

Thanks always to you. I think you have broad and deep knowledge on electric field.
Then I can use charge mode with confidence to run ICE during driving not to sleep ICE for several months by using EV and Charge Overnight Only. I have to consume 4-5 gallon for 3 months disregarding my annual mileage is 1,000 miles, which is 83 miles per month and it becomes 3 miles per day. 20 miles a week. What a short driving miles journey.

 

[antonvs]

Using charge mode will slightly decrease the life of the battery, but it shuts off at 80% of user-space charge. Charge mode is equivalent to a fast charge.

The batteries have a fixed amount of charge/discharge cycles, but...

... running the battery to zero before recharging it, makes the battery wear out faster.

Mostly this is managed by the car's software.

A daily recharge is best for lithium polymer batteries, and there is no need to discharge to zero before doing it.

This is the opposite to NiCad batteries, where daily charging reduces the capability of the battery, and frequent discharge to zero is recommended.

Good answer Andy, but for me it raises another related question. Lithium batteries in general usually have a life of 500 charge/discharge cycles. So assuming daily use does this mean the PHEV batteries would only have a use life of 1.4 years. I'm guessing (hoping) this is not the case as there would be people screaming. What is your take on this?

 

[AndyInOz]

Good answer Andy, but for me it raises another related question. Lithium batteries in general usually have a life of 500 charge/discharge cycles. So assuming daily use does this mean the PHEV batteries would only have a use life of 1.4 years. I'm guessing (hoping) this is not the case as there would be people screaming. What is your take on this?

The car's software protects the battery.

It does not allow the cells to be 'fully' charged, keeping some 'head room' to reduce the damage to the battery. I'd guess the 300 to 500 cycles usually quoted above is for people that charge batteries for radio control cars etc. where they fast charge from zero to one hundred percent. Charging to 80% capacity is usually quoted as improving the number of cycles to 1000.

I believe that our cars also have a built in charge floor that we are not allowed to pass, also to protect the batteries.

Personally, I have never used a fast charger. There is a warning in the manual that states (paraphrased):

Do not only use fast charge. If you use fast charge often, make sure that you also perform a normal charge at least once every fourteen days to maintain the battery.

This is probably because the cell balancing process does not run during a fast charge.

My car was one year old when I bought it, so I don't know how it was charged during the first twelve months (call those charges x).

I was charging three times per week for the first five years of my ownership, so that takes me up to x + 780 cycles (3 * 52 * 5). In three months time, I will have owned the car for 10 years, and the last five years I've been charging it at least once per week, so that's another 250 cycles, minimum.

So, so far I've recharged mine, more than 1000 times, and I don't know how many charges it received in the first year, while the car was on lease.

In summer, I routinely see a range guesstimate of 38 km after a charge.

We did have a member on this board who managed to kill a battery, but he was towing a three ton load (trailer plus earth mover) and charging twice per day (IIRC).

I don't think you have to worry about the battery only lasting 1.4 years.

Mine is nearly eleven years old.

 

[greendwarf]

As I recall from the Leaf fiasco lecture video the figure quoted there was around 2000 complete charge/discharge cycles - which would give at least 7 years for daily charging - again clearly not true in practice as mine is also almost 11 years old. However, it might be the reason why battery warranties are 8 years.

BUT the actual situation is more complicated than just that described by Andy because even when using the ICE the energy goes via the battery before powering the wheels, much of the time - essentially trickle charging - which should also age the battery. Quite how this all plays out over time we have yet to see.