Check the manual. My Ampera (a my13) will top up the 12v battery if left plugged in every now and again so I leave plugged in when not using. The Niro may well have a similar function.

I would think as the car has a limit on the charge level then its fine to leave it plugged in however I always unplug mine when lightning is around as a local strike could in theory spike the electronics in the car. The open contactor probably is not enough to stop a really high voltage spike.

 

I have left my EVs plugged in when not in use for the past 7 years. It doesn’t make one jot of difference as far as the battery is concerned. The OBC remains in a Charge Delayed mode until it gets the next instruction to charge.

That said, my EVSE is in my garage. Those whose EVs are parked outside may need to give some thought to long-term pin corrosion.

 

I leave it plugged in, that way if I decide I need 100% I don’t need to go outside I can just do it from pod point app.

 

I leave mine plugged in too, it sorts itself out .

Plus I need to really for the preheating function.

 

I used to leave the cable plugged in but have taken to removing it if it reaches my set level and it is convenient to do so on the basis of this wording in the Mercedes on line guide for the car:

• If leaving the vehicle idle for lengthy periods, park up the vehicle with a high-voltage battery charge level between 30% and 50%. Do not keep the high-voltage battery continuously connected to power supply equipment.

Clearly a few hours overnight is not the same scenario as leaving it connected it for days but I assume there is some reasoning for the advice.
Again I say are we all too neurotic about these issues with the batteries, probably, but I want the best performance out of mine all the time I have the car so if I can take reasonable action I will.
Maybe one of our more knowledgeable members will come along and give a view on why Mercedes advise what they do. I am lucky the theft issue is not one I need worry about the vast majority of the time however I do as a matter of course always make sure the cable is left locked away when I leave the house on the basis it is an easy thing to wander off with should a tea leaf pay a call and see it.

 

Thanks for your comments.

I think that whatever the manual says is the way to go, of course, but AFAIK the niro manual doesn't give any guidance on the subject

I too agree that we all tend to obsess a little bit over small issues and this is probably one of them but it is always good to know what is best.

 

My Volvo XC90 PHEV used to discharge the 12V battery if the charging cable was left connected without charging...

 

Interesting can anyone explain why? I assume it was some sort of constant monitoring going on🤷‍♀️

 

I unplug it when I need to use it, no matter if that's an hour after the charge has finished or a couple of days.

 

The problem is, hearing everybody else’s views or personal obsessions doesn’t necessarily tell us what’s ‘best’, so in the absence of any guidance from Tesla or VW I tend to leave ours plugged in until they’re next used.

I can see the case for electrical storms ruining your day if it was plugged in and there was a strike on your supply though, along with the charge socket possibly being more protected from water ingress and frozen water/snow in cold weather if it wasn’t.

That said, I haven’t had any issues leaving any of my EVs plugged in for extended times for the last 8 years, so I’d conclude it doesn’t really matter what you do.

 

It's not an issue for me as I use the car every day ☺ or I don't plug it in if I get home with over 80%

 

The Ampera Owner's Manual Model Year 2014 Edition June 2013 states:
"The vehicle must be plugged in when the temperatures are below -25° C to operate properly and to maximise high voltage battery life. However, we recommend plugging in the vehicle when temperatures drop below 0° C or raise above 32° C."

The implication being that the car will operate its battery temperature management system under extreme temperature conditions. I don't know whether this is true for any more recent cars.

 

If you've got a charge limit on the vehicle, then leaving plugged in can mean that any remotely controlled or timed temperature pre-conditioning can come from mains power, not take charge from the battery.
Other than that, it doesn't really matter, unless the vehicle designers done something silly.
Proviso: If you're on a new-fangled GB smart charger regulations thing, then the chargepoint software designers may have mis-interpreted the regulations and it might stop the vehicle resuming to draw current on a previous charging session until off-peak if your vehicle suddenly wants some power for pre-heating the cabin in the winter.

 

edited

 

Paul
My diagnosis is that you have bought an eNiro.
Ergo you are now rapidly running out of things to worry about

If I were you, I’d be getting worried about that 😂

I think you misunderstand my reasons for posting a lot of the time... I am not "worried" about it... I am interested in hearing what others think as it is an interesting topic of discussion especially for newbies. I fully understand that experienced people on here may not be interested in discussing then that is fine... don't. But others might be interested and willing to give me their views.

Sorry to disappoint you. No danger of you running out of ways to make unnecessary, unfriendly and snidey remarks though is there

 

Yes.

• I don't use the car every day.
• My car's four years old and has the original 12V battery.
• That 12V battery will be degrading.
• Keeping the car plugged in will top up the 12V battery when needed.
• I don't have to remember to plug in the car specially if it's going to be a cold day and I want to preheat the car.
• I don't have to go and plug in the car specially if my plans change and I want to charge to 100% for a long trip the next day. I can just use the app.

 

I use the charging schedule in the car to only charge between 00:30 and 04:30 and that bit is working well. But I didn't use the car at all yesterday so I didn't have cause to unplug the cable. Obviously the car is already at 80% (my max charge limit) so even if it was plugged in last night it wouldn't have charged but it got me thinking... should I make a point of unplugging the car if it is already at 80% or is it OK just to leave it plugged in?

Yet another vote for absolutely nothing to worry about.
If it keeps the 12V topped up in that state (I don't know if it does, but it might) that's a bonus.

 

I unplug my car. Just feel it draws less attention

 

It draws less electricity as well😂😂😂😂

 

I have a 2014 Leaf 24 that is left plugged in all the time at home. It is still on 12 battery bars and on its original 12V battery.

I use the charge timer to charge to 80% every morning except Monday, when it is set to 100%.
The car gets used for a ~40 mile round trip commute Monday - Friday. Sometimes it gets used at the weekend, sometimes not.

 

I have a 2014 Leaf 24 that is left plugged in all the time at home. It is still on 12 battery bars and on its original 12V battery.

I use the charge timer to charge to 80% every morning except Monday, when it is set to 100%.
The car gets used for a ~40 mile round trip commute Monday - Friday. Sometimes it gets used at the weekend, sometimes not.

Sounds like your car is going really well... long may it continue.

I have noticed that cars that are regularly used and regularly charged seem to do quite well... at least with the older Leafs anyway. I hope it is the same with newer cars too.

What is the car milage?

What does the GoM read?

 

Now this may just be psychology (amateur) but I think that having the car plugged in may deter theives. They would have to cut a potentially live cable to forcibly take it away.

What do you think?

 

@jmacneil re your (hopefully still) good 12V battery:- does your car have the solar spoiler? I've never had (touch wood) 12V Leaf battery issues either and am wondering if the PV insert it sports has actually done some good?

 

Nope. Just the plain vanilla one.
Anyone know what voltage I should expect across the 12V when the car is off if it's still in decent nick?
Occurs to me it might be worth sticking a meter on it to check, if that will give a sensible answer (e.g. be concerned if the measured voltage is below 12.4V)?

 

I've always left mine plugged in but the chargepoint door lock mechanism started through in up error messages which cleared after driving about 10 miles so I started unplugging it qfter charging and the error has cleared itself, the charge port mechanism is open to the elements while it's plugged in.

 

When the 12V battery is actually being charged it goes up to 14.2V on my car

 

To push current into a battery you need to put a voltage across the battery that is higher than the battery’s open-circuit voltage. Something between 13.8 and 14.4V is normal charging voltage. However this is not the battery voltage it is the charger voltage.