Verification first: retailer plans, time windows, rates and conditions can change. Check the plan at the date of the proposal. No saving is promised by this guide.
What a “3 hours free” offer can mean for a battery
Some retailer plans may offer a defined three-hour period at no charge. If the plan is available to your household and the battery controls support scheduling, an eligible battery can be set to charge from the grid during that window. On poor-solar days, that may leave more stored energy available for later use—but it is not an automatic saving, and it will not necessarily fill every battery.
Read the complete retailer plan
Do not judge a plan by one attractive period. Check rates outside that period, daily supply charges, export treatment, every time window and any participation conditions. Energy Made Easy provides an independent government comparison service for South Australia.
Four things need to line up
- The current retailer plan must be available and suit the household.
- The battery and controls must support the intended schedule.
- The window and charge rate must allow useful energy to be stored.
- The household must have later use for the stored energy.
A simple worked scenario without a savings promise
Suppose a battery has usable capacity C, begins the window with stored energy S, can charge at rate R, and the window lasts W. The most it could add is limited by the smaller of C − S and R × W, before system losses and site controls. This shows why a window may fill only part of a battery. It does not calculate financial benefit; the complete tariff and later household use still decide that.
Cloudy days and winter: why the window can still matter
Where the selected battery and controls support it, scheduled grid charging can use the eligible free window even when solar generation is low. Depending on its starting charge, usable capacity, selected charge rate and household loads, the battery may reach a high state of charge before the evening period. The complete retailer plan and the energy you use later still determine whether it is a good fit.
Settings and handover matter
The household should understand where schedules are controlled, how solar charging interacts with grid charging and what needs review if the retailer plan changes.
Official source checked
Sources checked 23 July 2026. Recheck the retailer’s current plan documents when the proposal is prepared.
Related guides
Reviewed by the Adelaide SolarSafe installation team.
