I think batteries charge slower approaching 90%. Obviously the dumb algorithm does not take that into account, so thinks it will be accomplished in the 4.5 hours.

 

They slow down on DC rapids, but not really on 7kw AC. Depends on the car I suppose, but my Corsa still managed 7kW right up to 97%, when it finally slowed down to 3kW. That was on a DC rapid, when I really needed 100% - or thought I did; I got home with 7% remaining. I’ve never paid much attention to AC charging speeds - so long as it’s done in the morning, I’m happy. The OP obviously isn’t, so a simple solution might just be to ask for 95% - if it then stops at 90%, problem solved.

 

more likely to do with the car. Set the car to 100% and see what happens.

 

Make sure the car is set to charge immediately and disable the charge% ceiling or set it to 100%. Disable any other timers, like for pre-conditioning etc. Basically, make the car as ‘dumb’ as possible. Let us know what happens.

 

What limit do you have set on the car, or its app? I presume IOG is controlling the car and not the charger? If your car, or app, is at 80%, then IOG can't go beyond that. If car is at 90%, and IOG is set to 80% (by a specific time), then it won't go to 90% (might go a bit beyond, or less than, 80% depending when it checks).

Over winter I set EV to 90% and IOG to 85% for extra miles in winter. I get, typically, 86%. Will be dropping to 80% over summer.

If IOG is controlling the charger, it may be that the charger doesn't know the car's charge level.

 

I didn't think hyundai was still supported? I'm lucky sort of, I've got home charger that I let it do the charging schedule. Kona set to 100% and charger set to 80%. Just plug in when I get home and it's to 80% at 7.30am. not 100% reliable as sometimes the ohme doesn't pick up the initial charge level of car.