Batteries have gone from a niche purchase to something we get asked about most weeks. The technology has settled down, the federal rebate has made the numbers work for a lot more households, and electricity prices have done what electricity prices do.
Here’s the honest version: what a battery does, what it costs you, and who it actually suits.
What a home battery does
Solar panels generate during the day. Most households use most of their electricity in the morning and evening. Without storage, you export your cheap daytime generation to the grid for a small feed-in tariff and buy it back at night at four or five times the price.
A battery closes that gap. It stores your daytime generation and gives it back when you need it.
That’s the whole idea. Everything else — blackout backup, virtual power plants, time-of-use arbitrage — is built on top of it.
The three things that actually determine whether it’s worth it
1. Your evening consumption. Not your total usage — your after-dark usage. A household that’s out all day and home all evening gets far more from a battery than one that’s home all day using solar directly. Pull twelve months of usage data from your retailer and look at the overnight figure.
2. Your feed-in tariff versus your usage rate. The bigger the gap between what you’re paid to export and what you pay to import, the faster a battery pays back. That gap has been widening for years.
3. Whether you already have solar. A battery without solar is a much weaker proposition — you’re just buying off-peak power to use at peak, which helps but doesn’t transform anything. The federal rebate requires solar or a solar-ready installation for this reason.
Sizing it properly
The most common mistake is buying too much battery.
Work out your overnight consumption — the electricity you use between sunset and sunrise — and size to cover that, not to cover your entire daily usage. A battery that never fully discharges is capital sitting idle.
For most Melbourne households that lands somewhere around 10–15 kWh of usable capacity. Bigger houses, or homes with an EV charging overnight, will want more.
Two numbers to check when comparing systems:
Usable capacity, not nominal capacity. Manufacturers quote both. Usable is what you get.
Continuous power output, in kW. This is how much the battery can deliver at once, and it’s separate from how much it stores. A battery with plenty of stored energy but low output can’t run an oven, an induction cooktop and air conditioning simultaneously. If you’re going all-electric, this matters more than people expect.
Blackout backup — read the fine print
This is where most disappointment happens.
Not every battery provides backup power during an outage. Many grid-connected systems shut down when the grid goes down, for the safety of anyone working on the lines. If you want your lights on during a blackout you need a system specified for it, with a backup gateway installed.
Even then, backup is usually limited to selected circuits — lights, fridge, power points, internet — rather than the whole house. Ducted air conditioning and electric hot water are typically excluded because they’d flatten the battery in an hour.
Decide up front whether backup matters to you. Retrofitting it is expensive; specifying it at the start is not.
If outages are a recurring problem at your place rather than an occasional one, that’s worth investigating separately — see our guide to brownouts and blackouts.
The rebate, briefly
The federal Cheaper Home Batteries Program provides a discount of around 30% on installation, applied at the point of sale by your installer — you don’t claim it afterwards.
Since 1 May 2026 the support tapers by system size, and it steps down every six months. Victoria no longer has a state battery rebate of its own.
We’ve covered the mechanics properly in a separate article on home battery rebates in Victoria, because the detail changes often enough that it deserves its own page.
What the installation actually involves
This is the part most battery articles skip, and it’s the part that determines whether the job goes smoothly.
Switchboard capacity. A battery needs its own protected circuit, and many older Melbourne boards have no spare ways and no RCD protection. A switchboard upgrade is a common prerequisite, and it’s better to know that before you’ve paid a deposit on a battery.
Where it goes. Batteries have temperature limits and clearance requirements. A west-facing garage wall in a Melbourne summer is not ideal. Garages, laundries and shaded external walls generally work; roof spaces do not.
Weight and mounting. These units are heavy. They need structural fixing, and in some cases a floor-standing arrangement rather than wall mounting.
Grid connection approval. Your distributor — United Energy, AusNet, Jemena or Citipower depending on where you are — has to approve the installation. There are export limits, and in some areas they’re tighter than people expect.
Single phase or three phase. If you’re on single phase and heading toward an all-electric home with an EV, it’s worth having the three-phase conversation at the same time rather than twice.
Compliance. Battery installation is licensed electrical work under AS/NZS 5139, and both the battery and inverter have to be on the Clean Energy Council approved list to qualify for the rebate.
Who we’d tell to get one, and who we wouldn’t
Worth it: you already have solar, you use a decent amount of electricity after dark, you’re on a poor feed-in tariff, you’re planning to electrify (induction, heat pump, EV), or you genuinely need blackout backup.
Probably not yet: you don’t have solar, your household usage is low, you’re planning to move within a few years, or your switchboard and wiring need significant work first — in which case do that first, because it needs doing either way.
We’ll tell you which one you are. We’d rather do the switchboard you actually need than sell you a battery you don’t.
Talk to us
Registered Master Electrician (REC 25989). Tesla Certified Installer. Over 200 five-star Google reviews. Lifetime workmanship warranty on everything we install.
Send us a photo of your switchboard and twelve months of usage data, and we’ll tell you honestly whether a battery stacks up for your household.
Related: EV home charging setups · Switching your home from gas to electricity
