Newbie question. I'll be charging the EV tonight in the Octopus Go time of 00:30-04:30. This will take 7kW of load. I've also got the system set to take the battery to 30% in that time too so there's enough for the morning cuppas and son on before the sun comes around.
What will be the resulting action? Will the battery be drained but then be kept at 30%?
stevelewis I thought that would be the case. Thanks for confirming. 👍️
The fine detail of the required settings depend on whether you have a GivEnergy hybrid inverter alongside an EV charge-point from other manufacturer, or they are both by GivEnergy.
If the EV charge-point is from another manufacturer, then you need to be setting a time schedule in each of the 2 systems, and to avoid discharge from the GE battery in to the car, it is best to set the EV charge-point schedule to be slightly shorter by say 5 minutes at the beginning and end. This is because the live time clock within each of the 2 systems can be slightly out of sync.
Simon_C My current EV charger is a dumb one so when it kicks in, the 7kW draw will pull from the battery and the grid, which is fine as it's filled with free electricity anyway.
I had planned to get a Zappi to manage the consumption of excess solar but then the GE team announced their charger so I'll wait for that.
@Yorkie71 , but you do not want to be charging your GE battery from grid up to the 30% (even at cheap rate), then discharging in to the EV later, as there will be the round trip energy losses in the AC-DC-AC inverter conversion processes of potentially around 16%. This is why your 2 time schedules need to be synchronised. If you do not have any energy 'to spare' in the GE battery, it is more efficient to be charging the EV direct from the grid.
It is less of an issue when the GE battery starts above the 30%, because the discharge from GE battery down to 30% will probably have been free solar energy from the previous day.
Simon_C I get what you are saying. It's not a problem tonight as I have way over 30%. On the occasions that it would be below, both car and GE battery would be filling up from the grid at the same time as that's when the Octopus GO cheap rate starts. So in this situation, there would be no round trip loss. Unless I'm mistaken. Which is entirely possible as this is a whole new level of technology for me 🙂
The problem might be that the GE battery will not sit at 30% - they seem to discharge to say 28% then top up to 31% then discharge to 28% and keep doing that all night until the timed charge period ends.
I guess the vast majority of the car’s charge will come from the grid, but some of it may come from the GE battery too.
TX200 I suspect that you could be right. But sure how that could be prevented and have the same outcome though. I guess when the charger comes available then it will be able to control this and prevent battery drain. Hopefully.
TX200 I've seen a small amount of SoC ripple overnight on my system. I've put this down to minor changes in battery voltage due to temperature changes, etc. I've not seen my system charging and discharging at full tilt to hold SoC and certainly not dependent on any other domestic loads during the charge period.
If you charge to 100% then it locks out and stays there. Anything less and it does occasionally bounce a little trying to keep it steady but not very often.
This is a hangover from the "winter mode" setting that used to exist. It's just a thing.
If it really bothers you it's a very quick script via the API to set discharge rate to 0% during AC charge windows.
I believe the app is going to get "timeable pause" type update at somepoint which may also do this although they will need to seperate charge and discharge power settings from the current pause button for obvious reasons...
I just thought I'd circle back on this given that I ran the system as stated in my original post. I happened to be awake during the 00:30-04:30 window (due to the warm nights), and the system performed just as expected.
I'm happy with that. Thanks for the advice.