Speak EV - Electric Car Forums banner
1 - 20 of 26 Posts

·
Registered
Joined
·
13 Posts
Discussion Starter · #1 ·
Dear All,
I need to leave a car at an airport for 2 weeks.
Am I being paranoid about the battery?
It will be in UK summer time.
I would be really grateful for anyone's thoughts or experiences.
bw
Peego
 

·
Registered
Joined
·
115 Posts
I did this for 1 week, was at ~80% charge, came back at it was basically still at 80% charge. No issues at all. I think assuming you don't keep it at 100% and don't keep it at <20% you should be good regarding storing it for a longer period.
 

·
Registered
Kia Soul EV 2020
Joined
·
3,337 Posts
Don't sweat it. My car was left for 3 weeks last year. It will be soon again.

The only thing is: don't leave it at the extremes of the battery, either full or empty.
 

·
Registered
E-Niro 64kWh '4' since 9/20 (was Prius)
Joined
·
1,466 Posts
Agree with others, should be no problem. However, please ensure that the Battery Saver+ option is enabled (ticked) as this is needed in order to automatically daily maintain charge the 12V battery. Also, don’t leave anything connected such as Dashcams, OBD adapters etc as these could possibly cause 12V battery drain. The big battery should be absolutely fine. These cars don’t suffer from the so called 'phantom' drain whilst parked that some other cars are quite notorious for. Peter
 
  • Like
Reactions: Todor

·
Registered
Joined
·
90 Posts
Dear All,
I need to leave a car at an airport for 2 weeks.
Am I being paranoid about the battery?
It will be in UK summer time.
I would be really grateful for anyone's thoughts or experiences.
bw
Peego
Will it stay in one place and you take the keys, or will they keep the keys and move it off site? I'd be more concerned that they shut and lock it properly to save the 12v battery dying.
 

·
Registered
Joined
·
13 Posts
Discussion Starter · #8 ·
Will it stay in one place and you take the keys, or will they keep the keys and move it off site? I'd be more concerned that they shut and lock it properly to save the 12v battery dying.
Hi We got the cheapest option which was it staying in one place, thanks for that though i had not considered it and will remember it for the next time we need to park
 

·
Registered
Joined
·
13 Posts
Discussion Starter · #9 ·
Agree with others, should be no problem. However, please ensure that the Battery Saver+ option is enabled (ticked) as this is needed in order to automatically daily maintain charge the 12V battery. Also, don’t leave anything connected such as Dashcams, OBD adapters etc as these could possibly cause 12V battery drain. The big battery should be absolutely fine. These cars don’t suffer from the so called 'phantom' drain whilst parked that some other cars are quite notorious for. Peter
Thanks, i had not seen that, will look at the manual to see how to work it
 

·
Registered
Kia e-Niro MY20 64 kWh - Gravity Blue
Joined
·
1,607 Posts
I get not leaving it really empty, but why can't you leave it full? Quite new to this EV world!
100% charge puts excess stress on the battery when left for a long time. A battery is basically a bunch of chemicals thrown together which will react when left at a high or low SoC. They call this parasitic reactions. So it's best to avoid leaving the car at a high SoC for long periods.
 

·
Registered
Ioniq 38kwh 2020
Joined
·
1,010 Posts
I get not leaving it really empty, but why can't you leave it full? Quite new to this EV world!
I get not leaving it really empty, but why can't you leave it full? Quite new to this EV world!
It's supposed to be bad for the battery especially in high temperatures. But in reality you aren't likely to park up at 100% anyway after driving there
 
  • Like
Reactions: Green_Viper

·
Registered
Kia Soul EV 2020
Joined
·
3,337 Posts
I get not leaving it really empty, but why can't you leave it full? Quite new to this EV world!
It is more of a compromise in battery management. Battery chemistry is like cooking. Too much or too little is known to be bad. So, the compromise of "least damage" is leave it half-empty or half-full, depending on your preferred world view. ;)
 

·
Registered
Kia e-Niro MY20 64 kWh - Gravity Blue
Joined
·
1,607 Posts
And besides that, virtually every EV battery when indicating 100% is at about 90% anyway, quite clever these motor manufacturers.
That's a common misconception. It is true that EV batteries in most cases are not used to their full capacity, but a 10% difference between what the BMS indicates and the actual max voltage of the battery is probably not in line with reality. The e-Niro battery is assumed to have a gross capacity of 67 kWh, 64 of which are available. That's only a 5% margin which also serves to make sure the battery is never discharged to its minimum capacity. So it's safer to say that 100% BMS SoC is more like 96% or 97% battery SoC.
 

·
Registered
Joined
·
1,007 Posts
That's a common misconception. It is true that EV batteries in most cases are not used to their full capacity, but a 10% difference between what the BMS indicates and the actual max voltage of the battery is probably not in line with reality. The e-Niro battery is assumed to have a gross capacity of 67 kWh, 64 of which are available. That's only a 5% margin which also serves to make sure the battery is never discharged to its minimum capacity. So it's safer to say that 100% BMS SoC is more like 96% or 97% battery SoC.
Well maybe the e-Nero battery/BMS is different to most then.

I know the i3 has a 10% true buffer built in, I had the BMS diagrams a few years ago.
 

·
Registered
Ioniq 38kwh 2020
Joined
·
1,010 Posts
That's a common misconception. It is true that EV batteries in most cases are not used to their full capacity, but a 10% difference between what the BMS indicates and the actual max voltage of the battery is probably not in line with reality. The e-Niro battery is assumed to have a gross capacity of 67 kWh, 64 of which are available. That's only a 5% margin which also serves to make sure the battery is never discharged to its minimum capacity. So it's safer to say that 100% BMS SoC is more like 96% or 97% battery SoC.
Doesn't it also depend on what the maximum cell voltage is, I think it's often set lower now anyway to reduce degradation?
 
  • Like
Reactions: Boxbrownie

·
Registered
E-Niro 64kWh '4' since 9/20 (was Prius)
Joined
·
1,466 Posts
And besides that, virtually every EV battery when indicating 100% is at about 90% anyway, quite clever these motor manufacturers.
It’s actually at 95.5% real SOC when displaying 100% on my 2020 '4' Eniro. You can read the actual real and displayed SOC values direct from the BMS via an OBD scanner. Despite this, It’s still healthier not to leave it long at 100% displayed value. The optimal storage state recommend by battery makers for Lithium Ion cells is around 40-60% SOC. When supplied brand new and unused from the cell factory, this is where they usually sit at. Peter.
 
  • Like
Reactions: Xinix

·
Registered
Joined
·
1,007 Posts
It’s actually at 95.5% real SOC when displaying 100% on my 2020 '4' Eniro. You can read the actual real and displayed SOC values direct from the BMS via an OBD scanner. Despite this, It’s still healthier not to leave it long at 100% displayed value. The optimal storage state recommend by battery makers for Lithium Ion cells is around 40-60% SOC. When supplied brand new and unused from the cell factory, this is where they usually sit at. Peter.
But two weeks isn’t a long “storage” period, regardless maybe the Eniro is not so well protected I guess.

BMW recommendation is to keep it plugged in for long periods of non use, I guess that’s the difference in BMS protocols.
 
1 - 20 of 26 Posts
Top