So what wall charger should i get, if i need a wall charger that i can dynamically change the charge current on ?
I have a solar system, and it is integrated into HA, so i have “Watt generated from Solar panels” and “Current wattage being used by house”
What i basically want is to set the charge wattage at the charger, dynamically to “Watt produced minus watt used by house” to be able to maximize my “self-use” of power, whenever i want to charge my car.
It does not have to be totally dynamic, if it just has “X speeds / wattages” it can deliver at, i can work with that, and just drop to the highest setting, below what i produce.
I have just wrestled automations for load balancing e-go charger. It is cheap (about 650€), 3 phase 16A or 32A depending model.
I dont have solar system, but i have only 3x25A main fuse, so i must balance load to keep total current under that.
I just posted my automation here, and results look like this. Blue is charging current, red is total mains current (for only phase, in this case 2 phases are below that, so i left them out of graph). Target max current in automation linked is between 19 and 22A.
Edit. For solar use it is possible to change between 1 phase and 3 phase on mqtt. If your solar system is only on one phase that could be useful.
Looks promising, but also very scary for a non-programmer.
I have a system where a smart meter measures the powerdraw on all 3 phases and then combines these.
The system then tries to balance the load so that i send just as much out on the one phase it has, as i consume on all 3 phases.
Essentially i am able to draw 3600 watt’s from one phase, as long as i also feed 3600 watt’s back into the system.
So if i draw 1200 watt’s on 3 phases, and my solar system feeds 3600 into one phase i am essentially charging for free (But since my house offcourse always draws some power, even in “standby”) i would like to use that max number.
What is MQTT ? (I am a bit of a novice, i mainly have integrations where there is no programming involved, as i seem to botch that up pretty bad)
I assume, that smart meter measures only power from grid? If so, it should be quite easy to make automation so, that it tries to keep energy taken from grid at zero. Automation that i linked tries to keep energy from grid between 19-22 amps, yours propably should meter wattage and target at 0w and balance charging power against that.
I have multiple “sensors” already inside Home assistant, as the Growatt system i own, has full integration into HA.
What i was aiming for was “Power produced by solar cells” minus “Power consumed by other stuff” = This is the charge current i want.
This way, i can use all of the power that is “surplus” because if i sell it i get very little for it, but when i buy it back, i have to pay government tax on top of the electricity price.
I am literally a noob, i would not even know how to make a new “sensor” that has the result of the 2 sensors i mentioned in it.
I really tried a few times, but every time i try to do something, for some reason it just do not want to do what i want it to do, i think HA, hates me
I found a few chinese boxes that can be set in intervals (6/8/10/13/16 A), but it seems that i have to select the charge current, which is a bit annoying to have to do, every time someone increases the use of power in the house, or clouds get between my solar panels and the sun. This is why i wanted it to be automatic, but i have been unable to find anything where the integration is more or less plug and play (Point it at some sensors, and the rest just works.)
The next best thing to “So easy that even i can figure it out” would be to find something that will work, and then pay someone to do the “coding” once the box is mounted.
If you can measure power taken from grid and power produced from solar, you just need to balance those two with ev charger. It really does not matter how much there is other needs for power (ac, heating etc). Just adjust charging power so that solar power equals grid power. If there is other consumption charging power is automatically be lower.
There is evcc (GitHub - evcc-io/evcc: Sonne tanken ☀️🚘) and it has somekind of integration with hass, but documenting is mostly german, and i can not understand it.
I actually managed to make a sensor that has the solar minus consumption so right now i have one single sensor that has the correct number.
If i have 1400 watt surplus, it will have a value of 1,4 …
So now i only need to find a suitable charger that has HA integration that i can feed this one number and have it set itself to charge with that amount of watt’s.
Careful, charging a car is not the same as charging a mobile phone or powering a heater.
As you probably notice, when you plug in a car, it takes a couple of seconds to start charging. This is because the car is performing several tests. In fact, the car and the charger are in constant communication. You need to look at the charger as a power socket that provides energy safely to the car informing him of what power he can take. The car is then the one that is limiting the power it is taking from the charger. If you cut the power or change parameters during the “startup tests”, you may get several errors in the car and doing this repetitive might damage it (specially powering it on and off, will heavily reduce the life of the relays inside the car that where not designed for constant switching on and off). Additionally, please notice that according to the ISO standards that regulates the cars and the chargers, you have set currents and minimum current (6A should be your minimum current, less than this might result in errors in the car and/or charger).
Disclaimer, everything I’m saying is theoretically, if you decide to do anything like this, do it at your own risk. Additionally, something that works with one car might not work with another car, same applies to the charger.
What I would do, consider minimum charging power 6A (220Vx6A=1.3kW), if your charger allows it, test the charger and the car’s you what to charge at different currents above 6A (such as 7A, 8A, 9A…), if not, use the pre-set current values (usually something like 6A, 10A, 12A, 16A…). Make sure that when you start a charging session, you keep it on at least 5 or 10min, and don’t change charging parameters in the first 1-2min. Some cars have API’s so you can use it to change the charging speed. Don’t change charging parameter more then once every couple of seconds, design your algorithm to be as stable as possible, even if you are not able to utilize your solar energy to the maximum.
There are chargers such as LEKTRICO brand that supposedly can be managed by HASSIO. Never tested them.
What i did was buy a generic wallcharger that supports setting it up for 6A, 8A, 10A, 13A, 16A before connecting the charger.
Now i usually just set it to 13A if we are at home, and 16A if we are not.
This way it will not use more power than the solar inverter can deliver, and since i have a battery pack on the solar inverter, it “smooths” out if the sun goes behing a cloud.
This charger cost 1/3 of chargers that were said to be able to do what i asked, and i found, that i would never be able to earn back that extra investment.
I can confirm that the LEKTRICO 1P7K charger works with HASSIO. You can start - stop the charging, set the charging current (6-32A, in 1A steps) + other settings.
I use this to manage the solar energy produced and balance it between house, EV and electric water heater.
So is this charger “online” and is it possible to dynamically adjust the charge current.
I am still on the lookout for some charger that Home Assistant can dynamically chance the charge current on, using a Home Assistant sensor from “Solar Assistant”
Basically i have a sensor that is “surplus solar” that does the following calculation (Current wattage produced by solar panels - current house load)
This figure is updates every 2 seconds and gives me the amount of solar i have to sell, unless i am able to use it (The price i get for solar is a lot less than the price i have to pay to buy so if i can charge the car with surplus solar, it is the cheapest)
Until now i have mostly been seeing solutions where i had to add additional current clamps to my system to do this calculation, but since i have it already in HA, it seems wasteful to have to install extra sensors.
What i need is a charger that can go from “minimum charge amps” (Usually 6A) upto 11 KW (3 phase 16A).
I will never reach 11 KWh with my current setup, but in winter i want to be able to pump as much into the car, on days where electricity is almost free, for a couple of hours in the middle of a windy night
But the charger needs to be able to adjust dynamically, without me having to stop the charge and adjust and start charging again.
