{"id":92821,"date":"2025-06-30T13:35:49","date_gmt":"2025-06-30T04:05:49","guid":{"rendered":"https:\/\/www.solarquotes.com.au\/blog\/?p=92821"},"modified":"2025-07-02T14:12:12","modified_gmt":"2025-07-02T04:42:12","slug":"old-inverters-new-battery","status":"publish","type":"post","link":"https:\/\/www.solarquotes.com.au\/blog\/old-inverters-new-battery\/","title":{"rendered":"Can You Add A Battery To Your Existing Solar? Here’s How To Tell"},"content":{"rendered":"

\"AnWith all the interest created by Australia\u2019s shiny new Cheaper Home Batteries Program, we\u2019ve seen enquiries soar for everything electric. One of the most common questions is: do I need to replace my existing solar system to get a battery? Here’s how to tell if it is possible to stick with your legacy solar, and how to add a battery to it if so.<\/p>\n

As early adopters<\/a>, Australians are finding themselves at a new cutting edge with the federal battery rebate prompting a rethink, rejig or total replacement<\/a> of their existing solar power.<\/p>\n

There are 4.136 million solar power systems in Australia and to be honest, about 12 million different options for adding a battery. Getting the right answer for your place will involve a trained expert visiting before install day.<\/p>\n

A call centre sales numpty, using an aerial photo, simply cannot assess a battery location,<\/a> existing solar wiring<\/a> or your switchboard.<\/a><\/p>\n

Saving Good Investments<\/h2>\n

Roughly speaking, I\u2019ve noticed $12,000, 12-year-old solar systems<\/a> turning up second-hand for twelve hundred bucks. Realistically they\u2019ll sell for half that.<\/a><\/p>\n

While panels that originally cost $1000 each really shouldn\u2019t go to waste, as prices fell, lots have proven to be poorer quality.<\/p>\n

If yours was a cheap basic system then it\u2019s not likely worth saving, especially if the array is taking up prime real estate.<\/p>\n

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If you recognise these units then yours is likely junk too.<\/p><\/div>\n

However, if it\u2019s working, the greatest value in your old solar power system is simply that it\u2019s already there. In most instances, the paid labour required to remove and\/or reinstall costs more than the used gear is worth.<\/p>\n

\"terrible

This arrangement was never any good to begin with, particularly given LG Chem’s issues.<\/a><\/p><\/div>\n

I\u2019ve always maintained that the best quality equipment and installation is the best value, because it\u2019ll prove reliable in the long term. When Australian labour rates for installation are such a large part of your outlay, bolting cheap gear to your roof, or cheap batteries to your wall, is a fool\u2019s errand.<\/p>\n

What About New Systems<\/h2>\n

If your solar is only a few years old,<\/a> there\u2019s a good chance you can just add a battery, but like any solar system, it\u2019ll need an inverter,<\/a> which is where things can begin to get tricky.<\/p>\n

Whether it’s inside or adjacent, the inverter\u2019s main function is to turn DC electricity from solar or battery into AC, which is useful to your house and the broader grid.<\/p>\n

However with rooftop solar now Australia\u2019s largest generator by installed capacity, AEMO are imposing rules, so inverters must respond to external network controls.<\/p>\n

The federal battery rebate<\/a> calls for inverters<\/a> and batteries<\/a> that are on Clean Energy Council approved lists, but don’t worry, if yours doesn’t appear it may just have fallen off. So long as it’s not been delisted,<\/a> a legacy inverter will suffice.<\/p>\n

\"cheap

There comes a time when a salad of cheap gear like this may need to be unified.<\/p><\/div>\n

With Great Power Comes Great Responsibility<\/h2>\n

Whether it\u2019s using emergency backstop or flexible exports, we occasionally have to put a lid on our roaring renewable success.<\/p>\n

So new systems must have a consistent internet connection or be choked off with a default low fixed export limit, which frankly doesn\u2019t help anyone.<\/p>\n

Depending on network rules<\/a> you may be obliged to bring all your equipment up the latest standards. While Victoria allows existing systems to be grandfathered, SA wants tighter control, sadly creating more e-waste because of it.<\/a><\/p>\n

If you have a faithful old SMA workhorse for instance, it\u2019ll likely get a bullet, but at least Fronius have the ethics to make their last ten years of production retrocompatible with a simple firmware update.<\/p>\n

The other possibility is a smart device like CatchControl<\/a> with a quick and dirty shutdown to make any old equipment behave.\u00a0<\/a><\/p>\n

\"Scrap

Without external controls, sadly these incredibly reliable SMA Sunny Boys are all rendered obsolete.<\/p><\/div>\n

Inverter Capacity Counts<\/h2>\n

With 17 different electricity networks<\/a> to comply with, there\u2019s no consistent answer, but generally speaking you\u2019re allowed 10kW of inverter generation<\/i> capacity connected to each phase of your supply.<\/p>\n

For some, this is a ceiling. Others allow a further 10kW of battery<\/i> inverter (20kW total) but then they still have an overarching 30kVa site limit.<\/p>\n

A hybrid inverter may count toward both allowable totals for generator and<\/i> battery inverter, or you may get even more capacity with a network investigation and special agreement.<\/p>\n

What Are The Options?<\/h2>\n

Dumb fixed export limits have been the standard for years so cheap installs simply used a 5kW inverter instead of a smarter, larger system with a customer consumption meter to impose a limit.<\/p>\n

So let\u2019s assume you have a single-phase supply, 5kW inverter with 6.6kW of solar. Here\u2019s a few scenarios:<\/p>\n

Add a 5kW hybrid inverter with battery and DC-couple more solar<\/h3>\n