Granny charge in stages to full

[darti3]

Hi, got a 2017 i3 last weekend and love it

Don't yet have a proper home charger installed. Have moved to a energy provider that gives cheap electricity 12-5am

I don't need to drive car much, could go 2-3 days without driving

Now, if I use the granny charger, understand this could take 20 hours to get fully charged

Would it do any harm to do this charging over 3 lots of 12-5am sessions over 3 days on a timer or would partial charging and then pausing like that be any type of problem?

 

[EvanstonI3]

If the timer shuts off the power to the ESVE (charger), it will cause the car to throw an error message each time. That's about it.

 

[mojo]

It should be no problem at all - I did a similar procedure on mine while I waited for an electrician to connect up my "proper" EVSE. I guess if the climatic conditions are extreme where you are, it might make charging efficiency a little bit higher or lower than charging continuously, but I doubt it would be enough for you to notice.

One thing to note though: even a "granny charger" can take a lot of current over a long period of time (depending on the setting, obviously) so make sure that if you use a timer, it has an adequate continuous current rating.

And, as EvanstonI3 says - you may find that the car will not resume after the timer has switched off and on again. If the car generates an error message (due to the power going down) then it always (on my car) seems to need to be unplugged and plugged in again.