I am in the process of changing Electricity providers to take advantage of free or low cost hours to charge my EV.
I have been using the Solar Diversion feature on the E2 Plus during the daytime on good weather days and it works well with a schedule setup to Solar Divert at all times and my home battery not being drained.
My question is can I set up a schedule for a few hours of night charging at low or for free, where I can charge from the grid and not have my battery power being drained and when the allotted time is done charging that the grid is no longer used and the home battery kicks in to supply power to the house for the remainder of the night.
What you want to do can be achieved with help of a home automation system like Home Assistant. It’s free to run on your own hardware or can run on relatively cheap dedicated devices. You connect the Evnex charger, SunBattery and the Xpeng charger to the Home Assistant via free integrations and set up automations to do exactly what you need.
For example, at midnight, check the battery level of the Xpeng, if it’s below x% then read the current battery level from the Sungrow Battery and set the battery reserve to that level then set the Evnex to Charge Now mode. It can then monitor until the Xpeng battery reaches a desired %, or until the Evnex charger stops drawing a current, then turn off Evnex Charge Now, and reset the reserve battery level in the Sungrow battery to it’s prior value. An automation as simple as that would draw power from the grid while the car was charging, then revert the home to battery power once the charging was complete and do it every day, completely autonomously. You can make the logic as simple or as complex as you like.
Something like this could be very simply implemented by anyone with basic logic skills and a bit of trial and error after initial setup of the system.
I have just purchased an Asus N150 Intel based barebones NUC mini pc with 16g ram and 1tb onboard NVME SSD for use as a hardware video decoder for my Home NAS. Would this PC be sufficient for the Home Assistant do you think ?
For a home assistant, N150 NUC is more than sufficient.
HA works well on a Pi, thus 16GB RAM + NVMe is overkill in a good manner. That unit won’t even cause any problems for your automated setup of Evnex + Sungrow + Xpeng.
All you need to do is install Home Assistant OS on it (or a virtual machine if you want isolation). plenty of headroom.
That is a powerful machine for HA. I used to get by with a raspberry pi that was a fraction of that (I’ve since upgraded)
Also regarding your battery if your sun grow has a “pause” feature that would protect the battery. My solaredge has this feature and I just set it to pause during the cheap tariffs while the car battery is charging. If you’re on cheap (or free) electricity during this window then doesn’t matter much if the house is drawing power too.
Alternatively you can use the HA automations described above