Battery loses charge overnight

I’ve had my Zoe ZE50 for about 6 weeks now and occasionally she will lose about 3% charge overnight.

I was thinking this may have something to do with the cold weather?

Has anyone else experienced this?

What are you using to measure the difference? The car, the ONTO app or the Renault app?

I’m using the car. 43% last night. 40% this morning.

Could be the cold although there are some issues with the ZE50 losing SoH quicker than anticipated and a BMS update is required. Could be you’re seeing the result of both those issues. Keep an eye on it and if it continues as the weather gets warmer then your car may need the update.


Brilliant. Will do. Thanks for the info.

Could be down to rounding off as well making it look a larger difference. Perhaps last night it was 42.6% and this morning due to cold it’s dropped to 40.5% so only a difference of 2.1% so slightly less alarming!

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Hmm this topic interests me- we’ll receive our first BEV (an i3 from ONTO) mid next month and don’t have a driveway or a way to easily charge while parked on street near home (though within a mile there are a load of ubitricity points; unfortunately none in my parking permit area)

How much charge does a BEV lose overnight or say during the week if it’s only used at the weekend? Obviously some is to be expected but a couple of % per day adds up quickly.

My plan/hope at the moment is to charge the car after hours the night before I know we’ll need it, which I think is fine, but this being our first EV outside of using an e-Golf via zipcar I’m definitely a novice!

The loss is nothing major. Don’t worry about it. The i3 actually seems to be one of the better cars in that sense too. Even with the ONTO Kit sitting there awake it should only be about 3% or so in a week.

You’ll quickly find a routine that works for you regarding charging I am sure, but don’t let the thought of battery drain put you off. Unless you have a Tesla it’s rarely a concern.


Yeah I saw this on ZE owners group YouTube…. He said if it’s a 20 plate it will need a update as the SOC is wrong. If it’s a 70 plate or 21 hour fine.
His was a 20 so obv needed the update. Quite helpful page for Zoe drivers with Onto.


Do we need to speak to @Onto-Team to arrange this? My Zoe GT also showing “book service” - due date June for A service.

You need to call Driverline (0800 030 6840) Then option 1 as an existing customer. Follow the options for servicing and they will get you booked in at a convenient time and location. ONTO Themselves don’t deal with this but rather their outsourced fleet management company, i247 which is who you speak to on Driverline.

Be sure to request a while-you-wait appointment, since you will need to stay there to unlock the car for the mechanic using your phone.


Many thanks @Koda, seen Driver line mentioned lots of times but never knew who they were lol. Figured I would find out at some point :smiley:

Just to add to what @Koda said, once you know when the vehicle is booked in, I’d call the dealership ahead of time, to check everything is in order. Remind them that’s it’s a while you wait service and that there is no key and you will give them access via an app. This is still new to many dealers and better to clear any issues up before the day, rather than on the day.

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Thanks @E7EV, yeah been reading some of the stories. Still in my first month and learning every day, another reason to love this community.

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