Hi there
I am very new to using my E2 charger, having only picked up my first EV a few days ago.
We have solar and two Tesla Powerwall 2 batteries.
Is it possible to set the charger to either pull from the powerwall, the excess solar, or the grid? At the moment it seems I have to manually tell my powerwall to not discharge to stop the charger from pulling from it. I’m not sure if my settings are wrong, or if it the installation needs to be changed.
Kristy
I have this setup, except I have 3x Powerwall 2’s. I have found some things that frankly annoy me. Because I live in a very wet/overcast environment in Australia.
Firstly the good news. Provided your solar is producing 1.7kw or greater, then the solar diversion will work. However if your Powerwalls are only capable of 15 amp each (as rated) then you do need a minimum of 2 kw from the solar as a minimum, and you might as well set that figure in Evnex. Its worth investigating if the 15 amp stated limit per Powerwall is indeed exactly that figure IN PRACTICE. Because a lot hinges on it.
But in my case as soon as it drops below that, say due to cloud, it will stop for a period and if the solar resumes long enough, will go back on charge. Because I have sufficient Powerwall capacity to draw 32 amps, I prefer to use the batteries as a shock absorber and simply set the Evnex to “charge”. However you could test if two Powerwalls will run at 16 amps each, as I think the capacity is 15 amps. You might be able to slow the charge rate slightly in your EV.
But for the bad news if you have Amber as your “wholesale” price but retail supplier. Because their Smart Shift, if left to its own devices, can decide now is a very good time to charge your Powerwalls, and the moment it puts more than (60 amp less 32 =) 28 amps down your grid supply, the Evnex will shut down on the basis that it is very concerned about overloading the grid feed. In my case it does this even if all 32 amps are coming out the battery, and nothing is being supplied to Evnex via the grid feed.
However you cannot in Evnex force a feed from the battery. The Tesla “smarts” will always charge out the battery rather than from the grid, and of course it is monitoring the solar feed and only taking the extra from the battery. The Evnex only has a CT (current transformer) on the grid supply so it actually only knows the ins and outs of that grid supply.
If the EVnex was actually OCPP compliant, then Amber would indeed be able to do some smart things. As it is i get lots of control over my Powerwalls using Amber’s app that I cannot do with the Tesla app.
My feeling about the Evnex charger is that its settings reflect the situation of people who dont have batteries - ie just solar. And those of us with the works have more sophisticated demands than its set up for at this time. This would probably not be an issue if Evnex actually was properly OCPP compliant.