Hello again fellow Givenergy users,
Please help me with this conundrum. Why is it, that no matter what I set with Battery Discharge settings [Reserve, max discharge] my 2 GEN1 5.2s end up being drained to 4% each morning that I charge my car?
There must be something obvious I'm missing? Is it the dynamic setting?
Many thanks
MaxG you'll most likely want to leave discharge as dynamic and set your charge target to the % you want to keep your battery to.
Can also looking into home assistant and givtcp if you want to get more involved.
MaxG Set the inverter to a timed charge for the same period as the EV is set and set the battery Charge to % to whatever value you want left in it at the end of the charge window.. The EV will drain the battery down to your Charge to % but then the inverter will hold it there until the end of the timed charge period. If the inverter doesn't play nicely with the EV charger, set the battery discharge rate to zero during the timed charge period.
Preventing the home battery discharge with IO, especially during the ad-hoc, smart charge slots can be tricky with the standard setting that are presented in the portal. Prior to being on IO, we had GO and that was easy because the cheap slot and the car charging was always the same so it was a case of setting the home battery to charge at the same time.
However since moving to IO, I had the same dilemma. Generally the slots tend to be 23:30-05:30 so one can set the home battery to charge in those times but if Octopus throw in a slot outside that, even a 30 minute slot at 7kW can take a lot from the battery.
The solution for me has been to use Home Assistant and set up an automation triggered by the car charging which sets an action to pause the discharge. HA is a whole new level of geekery though which will need some research if you haven't ventured into that.
Yorkie71 even a 30 minute slot at 7kW can take a lot from the battery.
The maximum that the car can charge at is 7.2kW. However the maximum that the battery can supply is limited by the discharge rate of the battery and/or the throughput that the inverter can handle, both of which is a lot lower than 7.2kW (AIO users excepted)
My approach is to charge battery to setpoint (e.g. 100%) during the known Intelligent window 23:30 to 05:30, setting this in the app. IF IO charges the car in this window, all is good.
When IO charging falls outside of the off-peak window - as it did this morning, granting me an 09:00-10:00 charge slot, Home Assistant is used to 'catch' this event and Pause the battery; restoring normal state after the car charge activity is over.
There are some 'rough edges' in all of this: Intelligent Dispatch Slots are half hour blocks, but car charging can start and end at unpredictable times in these blocks. Furthermore, car and battery charging tends to have an exponential decay around the 100% mark, so there's no exact process which is obvious to me to set an automation. So I have done this in a rather lazy way: looking for high grid import to know that the car is charging (presently using > 3500W which suits my house) and then looking for low import to see that charging has 'pretty much' ended (presently < 2850W) - in both cases setting the battery state accordingly.
It seems to work well enough to be satisfactory.
Zakalwe I'm aware of that thanks. 2.6kW in my case but the post was about preventing discharge from the battery to the car in general. Even 30 minutes at 2.6kW is more than I want to lose to the car when I need it for the next day's peak time.