How to find cheaper charging periods for the energy you need

The cheapest electricity period may be too short to deliver the energy your vehicle needs. A useful charging plan has to consider price, available time, charging power, and losses together.

EVCharge.mobi helps turn that calculation into a charging routine. Start with our Cheapest EV Charging Hours tool to explore a realistic energy target, then use the EVCharge app to review and schedule periods on a suitable connector. The useful outcome is less manual price watching and a plan you can compare with completed sessions.

Give the calculation a realistic energy target

Open Cheapest EV Charging Hours and choose an available electricity bidding zone. Enter the energy you want to add to the vehicle, the charging power, an efficiency assumption, and a price horizon.

Use power your vehicle and installation can realistically sustain. A charger's rated maximum can be higher than the power the vehicle accepts or the site makes available.

The efficiency input accounts for the difference between electricity taken from the grid and energy reaching the vehicle. For an illustrative target of 30 kWh and an assumed efficiency of 90%, the calculation needs about 33.3 kWh from the grid. At a constant 11 kW, that is roughly three hours and two minutes of charging. These numbers illustrate the calculation; they are not a prediction for a particular vehicle.

Changing the power or efficiency changes how much charging time the plan needs. That can also change which price periods are selected.

Illustrative prices: two selected hours supply 22 kWh from the grid at a constant 11 kW. These are example values, not a live quote; tariff extras and tax are excluded. Select the diagram to open it at full size.

The cheapest periods may be separated

The tool ranks the available periods by price and selects enough of them to cover the requested energy. It then shows the selected periods in time order.

That means the result can include gaps. Two inexpensive periods in the evening and another later period may be preferable within the calculation to a single uninterrupted session. Check whether your actual charging setup can follow that pattern.

The chart marks the selected periods and shows nearby prices for context. The estimate includes only the energy needed from the final selected period, even if the chart displays that period in full.

Choose a horizon that fits how long the vehicle can remain available. The tool is a planning aid: it does not know your departure time, battery temperature, or other demands on the site's electrical capacity.

Understand what the price includes

The public tool uses market prices for the selected zone. It does not include your electricity supplier's markup, network charges, taxes, or an operator's charging tariff.

Those costs can materially change the final amount you pay. A low market price is therefore a reason to examine a charging window, not a promise about the price on a public charger's receipt.

Compare the result with the tariff that actually applies where you charge. A fixed-price charging tariff may not pass a change in wholesale electricity prices through to you.

Available prices limit the plan

The tool can only use market periods currently available in EVCharge.mobi. Selecting a longer horizon does not guarantee that prices have already been published for every hour in it.

If there is not enough available energy capacity across the returned periods to meet your target, the tool cannot produce a complete plan. Revisit the horizon, power, and energy assumptions, or check again when more prices are available. Do not treat missing prices as free charging.

Put the plan into practice with EVCharge

The public calculator does not control your charger. Use it to understand the price pattern, then open a connector you can use in the EVCharge app. With a dynamic tariff, choose Smart, select or clear periods on the chart and check the estimate before confirming. Leave the vehicle connected and the charger online.

For a repeating owner-managed routine, open Charger settings → Automation. Smart automation requires a vehicle in your account and a dynamic tariff; choose the vehicle and daily ready time, then apply the settings. With a fixed tariff, scheduled charging may be appropriate instead.

After charging, open Insights and inspect the completed session. This connects planning with what happened. Actual energy and cost depend on prices, charger power, site limits and vehicle demand and can differ from the estimate.

Use the charging-hours tool for your first plan and the scheduling guide to carry it into the app. If you are connecting your own OCPP charger, the setup guide explains how to bring it into EVCharge.mobi.