EV range and SOC guide

Range anxiety is usually a units problem. Cars talk in kilometres remaining. Charging stations talk in kW. Your trip is actually kilowatt-hours versus kilometresat a speed and temperature you have not driven yet. EV Grids does not invent a new physics model; it uses your Wh/km and SOC settings to decide when to search for DC, then shows estimated arrival % on each stop card.

SOC is a tank gauge, not a promise

State of charge is the percentage of usable pack energy. It is not linear with kilometres if you climb the Western Ghats or sit in NH48 traffic with AC on. Two cars at 40% SOC can have very different remaining highway km. That is why the planner asks for Wh/km — energy per kilometre — instead of blindly dividing brochure range by distance.

The three numbers on every plan

How EV Grids reads your battery: below 30% it starts looking for DC, and it tries never to arrive under the 20% reserve. The gap between the two is your margin for traffic, detours and a charger that turns out to be closed.

Start SOC — what you leave with. 85–95% is realistic after a home or hotel charge. Starting at 60% because you “almost charged” is the most common way to add an extra stop.

Reserve SOC (default 20%) — the floor you do not want to cross on arrival at a charger. It absorbs a closed site, a wrong turn, and the last 10 km of “the plaza is just after the toll.” Dropping this to 5% to skip a stop is how people get towed.

Search threshold (default 30%) — when estimated SOC along the polyline hits this value, EV Grids looks for chargers. Higher threshold = earlier, safer stops. Lower = later, riskier, fewer sessions. Keep threshold above reserve. The SOC settings guide is the short version of this section.

Wh/km: the number that makes or breaks a plan

Vehicle presets ship with a typical highway efficiency (for example ~155–175 Wh/km on many Tata and MG crossovers, higher on large SUVs). Your number will be worse at 110 km/h, in 42°C with AC, with a roof box, or on a wet ghat. If your last 200 km of highway driving used 22 kWh, that is 110 Wh/km — unusually efficient — or 190 Wh/km if it used 38 kWh. Enter the honest average. Then enable hills & weather adjustment in summer or on ghat routes.

Rated range on a vehicle page is an ARAI-style full-range figure for orientation. Comfortable highway range is often ~60–75% of that number before you touch reserve. A 437 km Nexon EV Max is not a 437 km NH44 car at 100 km/h.

How EV Grids places stops

The planner walks the Google driving path, subtracts energy, and when SOC would pass the search threshold it ranks DC sites ahead of you. Arrival % on the card is an estimate from that walk — not a live telemetry feed from your BMS. If you drive faster than the assumption, you will arrive lower. Keep the reserve. Read how planning works for scoring (detour, power, cost).

Special cases

Cold and hills. Battery heaters and steep climbs spike Wh/km. Manali, Ooty, Lonavala ghats, and Western Ghat monsoon nights need extra threshold, not bravado.

Short commuter corridors. Delhi → Chandigarh at ~250 km can be a no-stop trip in a long-range EV starting at 90%, or a one-stop trip in a Tiago EV. Use Can I reach? before you skip charging at home.

800 V cars. Ioniq 5 / EV6 can recover SOC quickly if the station delivers. That does not mean you should arrive at 8% hoping the only gun works. Backups still matter.

Worked picture

Hyderabad → Bangalore is ~570 km. At 165 Wh/km you need about 94 kWh of road energy — more than a 45 kWh pack holds, so you will stop. A 75 kWh Harrier starting at 90% with 20% reserve has ~52 kWh usable for the road (~315 km) before the first search. That is why “one vs two stops” is a function of pack, start SOC, and speed — not a slogan. Plan the corridor with your preset rather than copying someone else’s Instagram itinerary.

Next: charging guide for connectors and queues, trip cost for ₹/kWh, and data accuracy for why a pin can be wrong.