Eco mode tries to minimise grid import and export. It will power the house using PV where possible. If there is excess PV generation then it will charge the battery. If there is not enough or no PV generation then it will use the battery to minimise import.
Timed Discharge forces the battery to discharge at full rate to wherever is possible- into any house load or into the grid. It's used when you want to maximise grid export (for instance when on Agile Export and you are getting a high price for exported power).
Timed Charge charges the battery at full rate from whatever source is available up to the SoC set in the Settings.
You can set the Timed Charge to whatever SoC you wish. If you set a Timed Charge for the same times as your off-peak and car charging times then the system will then charge or discharge the battery to whatever SoC you have set.
Think of it this way- Timed Charge allows you to exit the Timed Charge period at whatever SoC level you desire. Forget about what happens before that, just set the Timed Charge and SoC and the battery will be at that level when the Timed Charge period ends (obviously within the constraints of the system- you cannot expect it to charge a flat battery to 100% in say 30 minutes).
If you have Eco mode set, then it will resume that once a Timed Charge or Timed Discharge period has ended.
So, say you are on Octopus Go with a cheap period of 00:30 to 04:30. During this time you also want to charge your EV to take advantage of cheap rates. You also want your battery to exit that period at 75% so you can power the house in the morning and top it off with PV generation during the afternoon. Set the inverter into ECO mode to minimise grid import and export. Then set a Timed Charge from 00:30 to 04:30 and a SoC of 75%. At 00:30 the EV will start charging. If the battery is over 75% then the inverter will discharge it into the house load and EV until it hits 75%. If the battery is under 75% then the inverter will charge the EV AND the battery until the battery hits 75%. In both cases the inverter will maintain the battery at 75% until 04:30.
At 04:30 the car will stop charging. The Timed Charge period will also end and the inverter will revert to ECO mode and start to power the house load from the battery. It will continue to do that until PV generation can satisfy the house load. Any excess will then go into the battery.
At 00:30 the cycle repeats.
Does this help?