EV calculator methodology

Purpose and data version

Both SolaFi calculator routes use the same approved engine and 116 vehicle entries, imported into this release on 26 October 2026. The vehicle table contains battery capacity, consumption, AC/DC limits, range and stated test cycle. Some entries are marked as confirmed South African specifications; others use global specifications. These are dataset labels, not an independent certification. Check your exact model, year, battery and onboard charger with the manufacturer or dealer. Missing required specifications produce an unavailable result; an AC-only model is not treated as DC-capable.

Charging energy, cost and time

Energy drawn is battery capacity × (target state of charge − starting state of charge) ÷ 100 × 1.10. The 1.10 multiplier adds an estimated 10% charging loss; it is not division by 90% efficiency. Charge cost is that energy multiplied by the selected rand/kWh rate. Estimated added range uses battery energy before the loss allowance divided by the stated kWh/100 km consumption, multiplied by 100. Full-charge and per-kilometre costs use the same loss multiplier.

Charging time divides estimated drawn energy by the lower of charger power and the vehicle’s AC or DC limit. Home AC options are 7.4, 11 and 22 kW; indicative public DC options are 50 and 120 kW. DC taper, temperature, shared charger power, battery condition, auxiliaries and interruptions are not modelled in this simple time estimate. Actual charging often takes longer.

Tariff inputs and provenance

The approved source supplies these illustrative energy rates in rand/kWh: Eskom 3.56; Cape Town 4.54; Johannesburg 3.85; Tshwane 4.28; Ekurhuleni 4.23; eThekwini 4.17; Nelson Mandela Bay 4.50; other municipality 4.20. Its Eskom note refers to 2026/27. The source does not include dated official tariff schedules or source URLs establishing each municipality’s rate or the Eskom tariff category. These are editable calculator assumptions, not a verified current tariff quotation. Use the actual marginal energy rate from your latest bill or prepaid receipt. Fixed, capacity, service, connection and other non-energy charges are not included.

The road-trip comparison uses source assumptions of GridCars R8.45/kWh, Rubicon R7.00/kWh and CHARGE R9.15/kWh. Petrol comparison defaults are R26.92/litre and 8 litres/100 km. Their effective dates are not documented in the supplied source. Confirm current pump and charger prices, fees and availability before travelling. None of these values updates from a live pricing feed.

Driving, solar, batteries and supply

Monthly projections extrapolate the selected daily travel assumptions. Real consumption varies with speed, route, weather, passenger/load weight, driving style, tyres, heating/cooling and battery condition; stated test-cycle range is not a route guarantee. Plug-in hybrid calculations describe electric travel assumptions, not a complete prediction of petrol use.

The solar/battery timeline is an illustrative model using selected charging time, power and available battery energy. It is not a forecast of your roof’s output or a complete household energy simulation. Weather, season, shading, roof size, other household loads, inverter limits, battery reserves and time-of-use tariffs can materially change results. Solar energy assigned a zero grid purchase cost is not free equipment or a complete ownership-cost calculation. The supply checker and road-trip scenarios are planning aids, not electrical certification or navigation advice. Confirm installation suitability with a qualified professional and charging stops with their operators.

No quotation or guaranteed saving

Outputs do not include every ownership, installation, finance, maintenance or replacement cost. They are not quotations, guaranteed savings, credit approval or a recommendation to buy a particular vehicle or system. An enquiry starts an assessment through the selected SolaFi route. Your statutory consumer rights remain unaffected. See the website terms and privacy notice.