The economics depend on the price spread, usable capacity, efficiency and how much stored energy you consume later.
The Short Answer
Often, yes. Grid charging can make sense where the effective cost of storing cheap electricity is clearly lower than the price you would otherwise pay later.
The calculation
Start with the cheap import price, then allow for round-trip battery losses. Compare that effective stored-energy cost with the rate you avoid later in the day.
Usable capacity matters
A 10 kWh nominal battery does not necessarily deliver 10 kWh every cycle. Reserve settings, depth of discharge and operating limits reduce the usable amount.
You must actually use the energy
Savings are only created when stored energy displaces more expensive grid imports. Charging a battery that remains partly full at the end of the expensive period reduces the benefit.
Solar changes the strategy
If you also have solar, night charging must leave enough spare capacity for expected daytime generation. In summer, the optimum strategy may differ materially from winter.
Key Takeaway
Battery economics depend on the complete energy flow: what electricity costs when you charge, what it would cost when you discharge, what solar export is worth, and how efficiently the battery is used.
Frequently Asked Questions
Does battery efficiency wipe out the saving?
It reduces the saving, but a sufficiently large price spread can still make grid charging worthwhile.
Should I charge to 100% every night?
Not necessarily. The target state of charge should reflect expected demand, solar generation and tariff conditions.
Can this be automated?
Many modern systems allow scheduled charging; some platforms can also adapt schedules using tariff and forecast data.
Calculate Night-Charging Value
Model your cheap rate, daytime rate and realistic battery usage before changing the schedule.
Tariffs, supplier terms and export payments change. Check the current plan details before making a purchasing or settings decision.