Can I safely charge to 100% with my L2 home charger?

[ottsoul]

Hi,

Leased my first electric car Kia Soul EV (base model) last month.

I've been reading that it's bad practice to always charge lithium-ion batteries to 100%, over the long-term it will reduce the battery capacity.
So, I've set the schedule on my car to charge every night but only to 80% full.

But then I read on this forum that even though the battery size is advertised as 27kwh the actual battery size is 30.3kwh.

Therefore can I safely charge to 100% with my L2 home charger every night?

My daily commute is only 25 miles (round-trip) but on some days I might go 55-75 miles.

thanks!

 

[notfred]

If 80% gets you there, why charge more?

 

[wrickcook]

I have only had mine since Oct, but I am banking on the 30kWh buffer.
I use an L2 and charge to 100% every night. Commute 45mi round trip.

 

[tractioninc]

For what it's worth, "100% charged" isn't actually 100% of the capacity of your battery pack -- at least not when the car is new. There is logic built into the charging system to help limit the impact to the battery pack from charging to max capacity. And while there may be a measurable variance between the battery health of cars routinely charged to 80% vs 100%, it's small and produces effects gradually over time. How long is your lease? :twisted:

 

[ottsoul]

My lease is for 3 years.

I live in Ottawa (Canada), the winters are long and cold. In the summer I can get away with only charging to 80%. But I'm not sure what will happen to the range when the car is sitting outside all day at -20 degrees Celsius, and I have to run 2 errands after work. In that case I'd like to charge it to 100%, having the longer range gives me the confidence to make unscheduled trips.

However I don't want to ruin the battery or decrease my range by charging it to 100% unnecessarily.

 

[JejuSoul]

However I don't want to ruin the battery or decrease my range by charging it to 100% unnecessarily.

I own my car and want my battery to last. I prefer charging to 80% but will go to 100% whenever necessary. Similarly I prefer slower charging but will use Chademo whenever necessary. The main issue for degradation of a battery is heat. At -20 Celsius you do not have a problem with degradation. The problem in very cold weather is due to loss of range because the battery is cold, and air density is greater.

There is laboratory data for the deterioration of our our battery cells if left at 100%. See graph below. The results show that you should never leave your car for long periods at 100% charge in temperatures greater than 45 Celsius. You are in Canada not Phoenix, Arizona. This should never be an issue for you. (or me).

Data from U.S. Advanced Battery Consortium Report
FY2014_APR_Energy_Storage_R&D (for SK Innovation E400 see printed pages 47-49, on screen pages 95-97)

Calendar life tests are ongoing at four different temperatures of 25, 35, 45, and 55°C. Each battery is charged to SOC 100% at the C/3 rate and allowed to rest in an open circuit condition at the desired temperature for 4 weeks. At the end of 4 weeks, the batteries undergo 'Reference Performance Tests' at 30°C. Calendar life tests were conducted for 56 weeks and Figure II - 33 shows C/3 capacity retention at 25, 35 and 45°C after 56 weeks are 91.0%, 85.0% and 79.8% respectively. The 55 °C test reached 'end of life' after 24 weeks and the result of C/3 capacity was 81.0%. 
Figure

 

[notfred]

On a 3 year lease don't worry about it.

I'm in Ottawa, I bought mine and I intend to keep it for ~10 years. I got it last September so I've been through winter with it. I charged to 100% during winter and on the coldest days (and with winter tyres on steel rims) I would start with 100km on the GOM. Now it has warmed up again I'm only charging to 80% and getting 110km on the GOM. There was one day where the temperature was below -25C all day and then I think the battery heater kicked in because I lost a bit of charge with it sitting in the parking lot at work - I don't recall how much but I posted about it on these boards, it wasn't enough to worry about.

There aren't any Chademos around unless you head across to the Quebec side, but that should be changing soon (see the Ontario EVCO thread in the local discussions section). The lack of Chademo charging will also help battery life.

 

[ralyon]

One thing I do is use both schedules. There are 2 days a week where I take my son to soccer practice so one schedule has the night before both of those days and is set to 100%. The other schedule has the other 5 days and is set to 80%. That way I don't have to think about changing it manually so long as I have it plugged in before the charge time starts.

ralyon

 

[slobodanc]

Ignoring other factors, charging to 80% compared to 100% will double battery life. It has been debated on other forums for Li based batteries, such as LiCo.
Now this chemistry is different so may be different result. But that is roughly the rule.

 

[jstack6]

don't worry, go for 100% if you need it or feel more comfortable.
The battery cooling is the key to long life batteries. This chemistry and cooling should make it last 20 years or more.
The SOUL EV has the best chemistry and cooling of any EV.

 

[ralyon]

don't worry, go for 100% if you need it or feel more comfortable.
The battery cooling is the key to long life batteries. This chemistry and cooling should make it last 20 years or more.
The SOUL EV has the best chemistry and cooling of any EV.

I would be interested to see any details on this. Do you have any links?

 

[JejuSoul]

There's a thread on this forum Comparing Battery Chemistries with some links. My opinion is that the chemistry is good but it is more expensive than LG Chem's.

BTW the world's highest temperature for June 27 2016 was 51 degrees and occurred at Death Valley, USA. Am wondering how the SoulEVs in Arizona / Nevada / Southern California are doing in that heat. Seems even Tesla cars are having trouble coping - Air Conditioning Blowing Hot Air

 

[ralyon]

Thanks for the info!

 

[mysoulev]

i bought my SoulEV so definitely interested in getting maximum battery life. i'd be really happy if i could get 20 years out of the original battery, but none of my smartphone battery could last more than 2 years. with my current phone, i'm charging it to 80% only to see if it makes any difference.

i met another EV owner at a local charging station and he assured me that he always charge to 100% and he has seen no battery degradation on his 3 year old iMiEV. not sure if it is because of the reserve?

 

[tiburonh]

I'm not an electrician or a battery chemist, but my understanding is that the option of charging to 80% is really only there for use when charging at a public level 3 CHAdeMO station, and that's because those stations typically charge a flat fee for charging to 80% and then start charging a fee by the minute after that -- and that fee quickly adds up because the charger itself slows way down after the first 80%. Otherwise, when charging on a level two or level one, you should always feel free to charge to 100% without worrying about battery degradation.

 

[slobodanc]

80% option is available for scheduled (night) charging at home using L2 station.
I am certain it is for longer battery lifespan.
This has been discussed in great detail on other LiIon cell forums.

From memory, charging a LiIon cell to 90% instead of 100% can double the number of cycles. This is just a general rule as there are different chemistries in use.

 

[tiburonh]

80% option is available for scheduled (night) charging at home using L2 station.
I am certain it is for longer battery lifespan.
This has been discussed in great detail on other LiIon cell forums.

From memory, charging a LiIon cell to 90% instead of 100% can double the number of cycles. This is just a general rule as there are different chemistries in use.

In any event, there really is no need to worry about the battery life as Kia warrantees it for 10 years or 100,000 miles.