| 7 kWh AC Coupled Battery | 126 kWh Max Expandable | 2,896 kWh Exported to Grid | Any Inverter Brand Compatible |
Project Overview
Angela had a solar system installed five years ago in Frankton and had been told there were limits on which battery she could pair with it. She was right, until recently: Future Energy’s new supplier ATMOCE AC coupled battery works with any solar inverter on the market, regardless of brand or age. Rather than guessing at a size, we reviewed 13 months of Angela’s actual power data and found she had exported 2,896kWh back to the grid, an average of around 7.42kWh a day. A single 7kWh ATMOCE battery closely matched that pattern, with the option to add more 7kWh units, up to 126kWh in total, as her household’s power needs change.
The Challenge
Angela wanted to add battery storage to a solar system that was already five years old, and had previously been told her options were limited. That’s often true: many batteries are DC coupled, meaning they need to connect directly into the solar system’s wiring and typically require a hybrid inverter from the same manufacturer, which can rule out older systems or mixed brand setups altogether. The other challenge was sizing. Guessing too small would waste the opportunity to capture her exported solar, guessing too big would mean paying for capacity she would rarely use, especially with fewer people now living in the house and her consumption pattern shifting as a result.
The System
ATMOCE AC Coupled Battery – Compatible with Any Existing Inverter
An AC coupled battery connects on the AC side of the system rather than the DC side, so it doesn’t need to match or communicate directly with the existing solar inverter the way a DC coupled battery typically does. That made it possible to add battery storage to Angela’s five year old system without replacing or upgrading her original inverter, opening up a retrofit option that a DC coupled battery simply couldn’t offer.
Sized From 13 Months of Real Export Data, Not a Guess
Rather than sizing the battery off a rule of thumb, we asked Angela for her last 13 months of power data and found she had exported 2,896kWh back to the grid, an average of 222kWh a month, or about 7.42kWh a day. ATMOCE batteries come in 7kWh increments, so a single 7kWh unit was a close match to what she had actually been exporting, capturing the bulk of that surplus rather than over or undersizing the system.
Expandable to 126kWh as Her Needs Change
With fewer people now living in the house, Angela’s future export volumes are likely to grow rather than shrink, so the system was designed to grow with her. ATMOCE batteries can be expanded in 7kWh increments up to a total of 126kWh, meaning she can add capacity later without replacing what’s already installed.
The Results
- 7kWh ATMOCE AC coupled battery retrofitted to an existing five year old solar system
- No inverter replacement required, AC coupling works with any existing solar inverter brand
- Sized from 13 months of real power data showing 2,896kWh exported to the grid
- Average export of 222kWh a month, around 7.42kWh a day, closely matched to the 7kWh battery
- Expandable up to 126kWh in 7kWh increments as household power needs change
- A retrofit path for existing solar homeowners previously told their system couldn’t support a battery
Old solar system. New battery. No limitations.
Frequently Asked Questions
Can you add a battery to an existing solar system, regardless of the inverter brand?
In many cases, yes, though it used to depend heavily on the inverter. Traditional DC coupled batteries generally need to match or be compatible with the existing inverter, which can rule out older systems or certain brands entirely. AC coupled batteries like the ATMOCE installed for Angela connect on the AC side instead, so they can be paired with any existing solar inverter on the market, making a battery retrofit possible regardless of what was installed originally.
How do you size a battery for an existing solar system?
The most reliable way is to look at real data rather than guess. For Angela’s Frankton home, we reviewed her last 13 months of power data and found she had exported 2,896kWh to the grid, an average of about 7.42kWh a day. That figure pointed directly to a single 7kWh battery as the right starting point, closely matched to what she was actually sending back to the grid rather than using herself.
What’s the difference between AC coupled and DC coupled batteries?
A DC coupled battery connects directly into the solar system’s DC wiring, typically requiring a hybrid inverter from the same manufacturer or a compatible pairing. An AC coupled battery like the ATMOCE connects on the AC side of the system instead, working independently of the existing solar inverter. That makes AC coupled batteries a more flexible retrofit option for anyone with an existing solar system who wants to add storage without replacing hardware that’s already working well.
Can a home battery be expanded later if power needs change?
With the ATMOCE system installed for Angela, yes. The batteries come in 7kWh increments and can be expanded up to a total of 126kWh, so starting with a single 7kWh unit doesn’t lock the household into that capacity permanently. As circumstances change, whether that’s a home office, an EV, or a shift in who’s living in the house, additional 7kWh units can be added to the same system.
Have an older solar system and thought a battery wasn’t an option? Future Energy’s AC coupled battery range works with any existing solar inverter, so a battery retrofit doesn’t mean replacing what you’ve already got. Talk to us about sizing a battery around your real power data, not a guess.
