I've had an Ohme since October and not had any problems with charging as per the Octopus Go schedule. As long as you have the right tariff selected in the settings, then it will automatically start charging at 12.30 and turn off at 04.30 - which, in my case, seems to result in about 87 miles added. Then it's easy enough - if you're needing more, or to get it to full charge for a longer run - to select Rapid Charging from the dashboard (which ignores the tariff rate).
My charge history shows that the 87-ish miles usually costs around £1.30, using approx 25-27kWh.
I want (need) my car charged to at least 90% in the morning by 6:30am.
Depending on the day, when I get home and plug it in about 6pm, it could have as little as 10% battery remaining.
I want it to charge as much as possible during off-peak rate.
So I want it to start charging as soon as off-peak begins e.g. 12:30.
If it is finished by 4:30, great it'll all have charged during the off-peak tariff.
Usually it wouldn't be finished by 4:30 so the final part of the charge would be at peak rate.
Also, I want it to do any balancing that maybe necessary after it's done it's main charge to 100%.
This isn't really possible to achieve using the Ohme application.
In order to guarantee a full charge & it allows balancing, with Ohme you have to say you want 100%/163m added.
It obviously has no idea how much charge is already in the car so it assumes it it completely empty. It then works backwards from your set target time - 6:30am in my case, it then decides that in order for it to be at 100% by the target time it must start the charge before the off-peak period begins.
You can force it to only charge at the off-peak rate, which will make it start charging as soon as the off-peak begins, but it will then stop charging once the off-peak ends and therefore will not always be fully charged/plus it won't let it do any balancing.
It is "trying" to be too clever, when all I need it to do it start charging when the off-peak rate begins and keep charging/balancing for the next say 12 hours.
The other thing I forgot about, is you can't really tell when it is actually planning on charging as the scale on the graph it shows you to see this info is pretty useless.