Can you charge your electric car off-grid with a Zappi?
Charging your electric car at home off grid is nirvana for many. Is it really possible?
If you're a new EV owner, it's good to know that you can be self sufficient and not dependent on grid power. The Zappi is renowned for self consumption but can it still work when there's no grid connection and you are essentially off grid?
Charging an EV off-grid is NOT an unusual request
We often get approached by electric car owners and typically Tesla Model 3 owners, wanting charging setups that are outside the box but when Paul called us earlier this year and said he was living off grid and wanted to charge his EV we immediately knew 2 things.
1. It wasn’t going to be easy but
2. The Zappi was up to the challenge.
For those with offgrid setups, it's a common quest to remain offgrid while driving electric and without being dependent on patchy public electric car charging infrastructure. Most ev car owners boast about the convenience of charging their electric cars at at home so why shouldn't off grid guys and girls enjoy the same privilege?
The challenge when charging an electric car off-grid
Back to Paul's scenario. He has 15 solar panels producing up to 4.8kw feeding into a 24 cell battery array and obviously no electricity grid connection. The Zappi was never designed to be connected offgrid. So the challenge with the Zappi was how to simulate the grid connection to provide the Zappi with enough information to differentiate the solar generation and the stored energy in the battery array.
What are the off-grid charging principles?
Working with our team, Paul was able to come up with a solution that works and works well. The solution involved a separate AC connected solar and battery inverter. The inverter on the solar array converts the DC energy to AC from the solar array to service the house and a second inverter on the battery array converts the stored DC energy to AC to simulate the electricity grid for the Zappi to charge the vehicle. With this new setup Paul is reporting that his solar array is now more efficient with his battery array now being charged earlier each day and harvested energy being available for the charging of his EV.
How does charging off grid with the Zappi now work?
Very well! Essentially the Zappi sees the AC battery as the grid connection, pure and simple. In operation, to get the Zappi to work Paul needed to make changes to two inverters, a PV inverter 'generation' CT clamp which is the Fronius, and the battery inverter which is the Victron which runs the 'grid' CT clamp simulating a grid connection for the Zappi. We followed the Victron AC-coupling guide here to get the two inverters working together: https://www.victronenergy.com/live/ac_coupling:start
Paul then arranged the Zappi CT clamps as per the diagram provided by EVolution's Matt to get the Zappi working successfully.
The one caveat to off-grid is that when the house battery is full, the Zappi will just say 'Waiting for surplus' because the battery inverter tells the PV inverter to reduce the PV generation to almost nothing to prevent over charging the house battery, the work around to this is to set the Zappi to 'Fast' mode for a few seconds until the PV generation ramps up high enough, then the Zappi can be placed into 'ECO' mode.
The overall situation is that now Paul can charge his EV off grid and it's all due to the Myenergi Zappi. #Happizappi #EVcharging #EVolutionaustralia
For more information on Paul and his setup take a look at the links below.
Blog post: https://livingtinyandgreen.com/the-zappi/
Myenergi Zappi - Charge your EV from your PV - Australia NZ
Welcome to intelligent, solar-aware home EV charging
The EVolution team are proud to be partnered with myenergi, a future-focused and innovative company who design and manufacture a range of exciting EV charging products in England.