Hi. I’ve found conflicting guidance when researching how to best set up my system having recently taken delivery of my first EV. My system as follows: GIV-HY5.0 Inverter, Giv 8kw battery, Hypervolt Home Pro 3 charger, Tesla Model Y. I’m on Octopus Intelligent Go tariff (‘EV saver’ version as the car is from Octopus) and Octopus Outgoing fixed Export tariff. I’m really confused what should control the scheduling of charging, what inverter settings I need to charge the battery on the cheap overnight rate and generally how to optimise for least cost household usage. Any real world advice would be greatly appreciated!
If you are on Octopus intelligent Go the Octopus advice is to plug your car in and let Octopus charge your car (via the EV charger or the car) when grid demand is low. You will get extra bonus rate cheap slots if you do that.
However, depending on how your EV charger and givenergy inverter have been wired up, your inverter may be able to “see” EV charging load, and so when the car charges the inverter will discharge the home battery into the EV.
So most flexible is to ensure your EV charger and the givenergy CT clamps are wired in such a way that the inverter can’t see the EV load. Your inverter will remain unaware of these bonus rate slots but at least the battery won’t discharge into the EV when the EV charges. For your battery to be aware of, and take advantage of, the IGO extra slots requires something like Home Assistant or Wonderwatt.
Simpler is you just charge your EV in the overnight cheap period and set the inverter to also charge the battery at the same time. You won’t get the bonus slots but you won’t have to change your EV/inverter wiring if it hasn’t been done right.
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Many thanks for the reply. At the moment I have the simple set up described, with the inverter set to charge the battery at the same time as the cheap overnight rate (11.30-05.30) rate with IOG, with Octopus managing the charging schedule. Given I don’t anticipate needing to charge the car more than once or twice a week, I’m not overly concerned about missing the extra slots. However, I wouldn’t want the battery to be drained if there is a cheap slot when I have the car plugged in outside of this this time - for example if I plug it in in the afternoon ready for an overnight charge. How can I test whether the inverter can detect the EV charging load or not?
Simply look at the power flow in the givenergy app when your EV is charging, does the grid/battery power spike upwards or not?
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