Hey everyone! With Tesla's new support for always-on accessory ports, I'm curious about the potential of home battery systems that can draw power from electric vehicles (EVs) and other sources. For instance, the Model 3 can supply 144W from one port, while the Model Y provides up to 288W from two ports and even more with a direct DC connection. I'm wondering if there are battery systems available that allow for: 1. Regulating power from DC or AC inputs—like limiting the draw to 12 amps. 2. Taking input from multiple sources simultaneously, such as an EV and solar panels. 3. AC coupling with an existing solar grid-tie system after disconnecting from the grid. This setup would let me use solar energy during the day while keeping the EV as a backup after sunset. I've done some research but haven't found the perfect solution. What options are out there for achieving this kind of home battery system?
2 Answers
There are definitely DC-to-DC systems that can regulate current for EV charging, especially if you're working with a 48V system, which is efficient. You can also parallel multiple DC sources without much hassle. Plus, most hybrid inverters support AC coupling, so you should be good there too. Just keep in mind that as you scale, you might need a comprehensive management system to keep everything running smoothly, especially if you're drawing power from multiple sources simultaneously. Just be cautious with your budget; you might find an inverter and battery setup at the lower end, but expect to hit around $1,000 to $2,000 for a decent setup that can cover essential circuits in your home.
Many wired grid-tie systems allow you to set max output power throughout the day, but if the system exceeds the limit, it just trips the breaker. Most non-cheap inverters can combine solar and generator/grid inputs without a hitch. For your particular situation, brands like Sunsynk, Deye, and Solark can allow for AC coupling with the current limits you’re looking for. They can isolate excess power or turn the grid-tie inverter off when the batteries are full. Keep in mind, it's all about matching your inverter's capacity with your solar setup to ensure smooth operation, especially during outages.
For sure! AC coupling often requires a bit of protocol tweaking, like adjusting the AC frequency, to signal the grid-tie inverter about how much power to reduce. But how does the hybrid inverter prevent drawing too much from the grid? Is it smart enough to limit itself or do I need to manually set input limits?
Good point! Just remember that using the car as a low power source is quite different than actual vehicle-to-grid (V2G) setups, which usually require more advanced tech. For charging, if you go from DC to AC and then back, you need to set limits on how much your system draws to avoid overloading it.