House battery and Electrical Vehicle

Energy
1

Hi everyone,
I am renovating a house from scratch and I am evaluating whether I should install a home battery or not.

Leaving aside the cost factors, the doubt stems from the fact that I will install both solar panels and a car charging point.

The charging point will be installed by my employer and they will also pay/reimburse the car charging costs since it’s a company car.

My doubt: if I install a home battery it will recharge during the day while it’s sunny and I am not home.
Then if in the evening I come back and plug the EV in, I am quite sure it will drain the battery quite quickly, forcing me to grab energy from the network and nullifying the purpose of the battery.

Has anyone faced this issue already? Is there a way I can “split” the car circuit from the house one and prevent it to use the battery?
Of course I could install a completely separate meter but it will come at an extra fixed cost and I am not very keen to do it.

thanks!

2

You’re thinking about it incorrectly.

Purpose of battery is ONLY to provide smoothing and storage for when the grid or solar is unavailable. You can battery with or. Without solar and you can solar with or without battery. The only consideration should be. Do I want continuity of service when power isn’t coming in from the grid. And if so how long. That’s it.
That answer ltells you if you want /. Need a battery and everything else is moot.

Also I’m personally doing battery before solar because continuity oslf service is WAY more important to me than powwr generation

3

Hi, thanks for your feedback!

I am starting to think I am indeed missing an important piece…
Why would continuity of service be a factor in this?
My assumption (which I am now afraid might be wrong) is that I will be able to configure the system so that it will drag energy from, in order:

  • solar
  • battery
  • network

Under this assumption my worry is that an EV charging would instantly drain the battery (100KWh EV vs max 15 KWh of the battery) and I would need to grab energy in the evening from the network.

Am I missing something?

4

A properly built battery system handles the flow and knows where to draw from.

So with that assumption. A battery is designed to provide energy when you are cut from source…

Your assumption should be the battery and solar controller should be designed to work together to do this for you without blowing stuff up.

I am probably going SunRun battery because they work natively with my SPAN smart panel. This is an edit so I’ll explywhat that means next.

5

So my battery controller will handle charge discharge to my main transfer switch (in this case the span panel with a special lug for the battery)

It will provide the connection to the battery and communicatte with it as to charging and discharge state. Solar is similar. The system would be programed to handle not charging the car when only on battery
And a lot. Of other tricks.

That function in my system comes from span. So in yours you need to figure out how they work together and not blow it up.