Your home battery has one main job.
It powers your home during the most expensive part of the day. For most plans, that peak window starts around 3 pm and runs into the evening.
In this article, we’ll go through the one goal that matters when managing your battery.
We’ll cover how your solar and the grid work together to get you there, what the common settings actually mean and what to expect through winter so you can start the peak time of day with a full battery.
Disclaimer: Please make your own decisions about what is right for you, your home and your system when managing your home battery charging preferences and your retailer.
Why a Full Battery at 3 pm is the Goal
Peak time is when power costs the most. Every kilowatt-hour sitting in your battery at 3 pm is a kilowatt-hour you don’t have to buy at peak rates.
The reverse is also true. If your battery is half empty when peak pricing starts, you’ll be paying the highest rates of the day while capacity you’ve already paid for sits unused.
The measure of success is simple. Is your battery full when peak pricing starts? Everything else is just detail about how you get there.
Solar First, Grid Second
Your battery doesn’t care where its power comes from. A kilowatt hour from your solar panels and a kilowatt hour from a free or cheap grid window do exactly the same job at 6 pm.
A well designed system fills the battery from your solar first. If solar alone won’t get the battery full in time, grid charging tops up the difference during your free or cheapest window.
Some people feel frustrated when solar fills the battery during a free power window. They wanted the free grid power instead. The power from your panels costs nothing to make and the end result is identical; a full battery before peak time.
If you haven’t set up grid charging yet, we have a step-by-step guide for each ecosystem we support:
What Self-Consumption and Time-Based Control Actually Mean
These two settings cause a lot of confusion, so here’s the plain English version.
Self-Consumption
The battery fills from your solar during the day. Your home draws from the battery whenever it needs power. There are no schedules and no rates involved. The system just uses your own solar as much as possible.
Time-Based Control
You tell the system your electricity rates and times. It then makes decisions based on cost. That includes charging from the grid when power is free or cheap and holding back when power is expensive.
Some ecosystems take this further. Sigenergy and Tesla both have smarter modes that look at your rates, the weather forecast and your recent usage to decide when and how much to charge.
Which One Should You Use?
If your solar reliably fills the battery by 3 pm on its own, self-consumption does the job. If your battery regularly starts peak time short, especially in winter, time-based control lets the grid make up the shortfall at the lowest possible cost.
What to Expect in Winter
Winter is where grid charging earns its keep. Shorter days and heavier clouds mean solar often can’t fill the battery on its own. We regularly see local homes reaching only 40 to 50 per cent on solar alone through the colder months.
That gap is exactly what a free or cheap charging window is for. The grid tops up what the sun couldn’t manage and you still walk into peak time with a full battery.
In summer, the opposite happens. Your solar often fills the battery well before 3 pm and the system may skip grid charging entirely. That is normal behaviour. The system charges from the grid when it’s needed, so seeing it in winter but rarely in summer is a sign things are working.
Why Your Battery Sometimes Does Its Own Thing
Smart battery systems learn from your recent usage, usually the last seven days. If you’ve been away on holiday, the system may assume your home needs very little power and charge less than you expect. It settles down once it relearns your normal routine.
Weather forecasting plays a part too. If the system expects a sunny day, it may hold off grid charging and wait for solar. Most of the time it gets this right.
Give a smart system time to learn before changing settings. A day or two of odd behaviour after a holiday or a change to your plan usually resolves itself.
How to Check You’re Set Up for Success
You don’t need to monitor your system every day. A simple weekly check will tell you everything you need to know:
- Check your electricity plan and note when your peak window starts
- Glance at your battery percentage around 3 pm for a week
- Full or close to it most days? Your setup is working
- Consistently falling short? Your settings need a review
If your battery keeps starting peak time short, we can check your settings from our end.
Head to the support request page on our website and pop your details in.
Our team will review your configuration and make sure everything is set up as it should be.
The Bottom Line
The aim of the game is a full battery when peak pricing starts. Solar fills it first and the grid tops it up when the sun can’t get it there.
Get those two working together and your battery does its job 365 days a year, whatever the weather.
If your battery keeps falling short before peak time, our team can review your settings for you. Submit a support request
Frequently Asked Questions
What if My Retailer Doesn’t Offer a Free Power Window?
The goal stays the same. Look at your plan and find the cheapest time of day before your peak window starts.
Set your system to top up the battery during that window if solar won’t fill it in time. A full battery before peak time saves you money on any plan, free window or not.
Why Isn’t My Battery Full by 3 pm Even With Grid Charging On?
The most common causes are other loads competing for your home’s supply while the battery charges, an import limit capping how fast the battery can draw or a charging window that doesn’t match your current plan.
Check your window matches your retailer’s times first. If it still falls short, submit a support request and we’ll review the settings for you.
Do I Need to Change My Settings Between Summer and Winter?
Usually not. A correctly configured system tops up from the grid in winter and leans on solar in summer without any changes from you.
The exceptions are when your tariff changes or daylight savings shifts your times. Keep your rates and times up to date in your app and the system handles the seasons on its own.
Does Grid Charging Stop My Solar From Working?
No. Your system continues to prioritise solar whenever it’s available. Grid charging only steps in to top up the battery when solar alone won’t get it full in time. Your solar feed-in continues to work as normal.