Which charger do you need?
| Charger | Supply | Typical use | Circuit |
|---|---|---|---|
| Scooter / portable car charger, about 1.5–3.3 kW | Single phase | Two-wheelers, overnight car top-ups | Dedicated 16 A socket, 2.5–4 sq mm copper |
| 7.4 kW wall box | Single phase | Most home car charging | Dedicated 32–40 A circuit, 6 sq mm copper or as calculated |
| 11 kW wall box | Three phase | Larger batteries, two cars | Dedicated 3-phase circuit, sized by the designer |
Wire sizes are common practice for short runs; long cable runs to a parking area need a larger size to limit voltage drop.
Check your sanctioned load first
- 1Add the charger rating to your existing maximum demand
AC + geyser + kitchen + pump + charger, all running in the evening.
- ?Is the total above your sanctioned load?Yes Apply for load enhancement firstNo Go to the next check
- ?Single phase connection and charger above about 7 kW?Yes Convert to three phaseNo Go to the next check
- ✓Dedicated circuit, RCD and earth pit installed and tested
Our load enhancement guide explains the application to your ESCOM.
Worked example: adding a car charger to a 5 kW house
Take a three-bedroom house on a 5 kW single-phase connection with two ACs, a geyser, an induction hob and a sump pump. The family buys an electric car and the dealer offers a 7.4 kW wall box.
- Evening load without the car: one AC (about 1.5–2 kW), the hob (1.5–2 kW), lights, fans and the fridge. That is already close to 5 kW on a hot evening.
- Add the 7.4 kW charger: the total goes well above the sanctioned load, and the charger alone is above the 5 kW single-phase limit. The house needs conversion to three phase and a higher sanctioned load, say 10 kW.
- What that costs every month: 5 kW more sanctioned load at the domestic fixed charge of ₹150 per kW is about ₹750 a month plus tax, whether you drive or not. One-time costs are the three-phase meter, extra deposit and the board rewiring.
The cheaper alternative. A 3.3 kW charger running overnight for 8 hours puts about 26 units into the battery, enough for roughly 170–200 km at 13–16 units per 100 km. Most families drive far less than that in a day. With the charger on its own circuit and a timer that starts it after the evening peak, the house needs a much smaller load enhancement. Whether it can stay on single phase depends on the new total staying within 5 kW, which a house with ACs and a geyser rarely manages, so ask the subdivision before you buy. Our single-phase vs three-phase guide explains the conversion if you do need it.
The ESCOM assesses load from what is installed, not from when you use it. So declare the charger in your load enhancement application even if you plan to charge only at night.
Wiring and protection that the charger needs
- A dedicated circuit from the main distribution board. Never share it with other sockets.
- Residual current protection. EV chargers can leak smooth DC current that blinds an ordinary Type AC RCCB. Use a Type B RCD, or a Type A RCCB where the charger has built-in DC leakage detection (check its manual).
- A good earth. Charging happens outdoors on wet floors. A dedicated earth pit with low resistance is essential. See our earthing guide.
- Weatherproof mounting at a suitable height, away from where water collects.
- Surge protection at the board, especially in thunderstorm-prone areas.
What a proper installation looks like
Car dealers often send an installer with the wall box. That installer fits the charger; he does not always check your distribution board, earthing or sanctioned load. Have your own licensed contractor check the work, or do the circuit and earth pit before the charger arrives.
If you are unsure what each protective device does, our guide to MCB, RCCB, RCBO and ELCB explains the types and why an ordinary Type AC RCCB is not enough here. Houses in thunderstorm-prone areas should also read about surge and lightning protection; a strike on the line can destroy a charger's electronics and the car's on-board charger with it.
Charger features worth paying for
- Adjustable charging current. Lets you cap a 7.4 kW unit at a lower current if your load or cable is limited. Useful while a load enhancement is pending.
- Scheduling. Start charging after the evening peak, when the AC, geyser and kitchen are off. Many cars can do this from their own app too.
- Load management. Some wall boxes read the house current through a sensor on the incoming cable and slow down when the house load rises. This keeps you within your sanctioned load without thinking about it.
- Built-in DC leakage detection. Allows a Type A RCCB instead of the costlier Type B. Check the manual for the exact wording before you rely on it.
- Outdoor rating. For open parking, choose a charger with a suitable ingress protection (IP) rating for rain and dust.
Also check your car's on-board charger. Many cars accept only 3.3 kW or about 7 kW on AC. A 11 kW three-phase wall box will not charge such a car any faster than its on-board limit.
What it costs to charge
A typical electric car uses about 13–16 units per 100 km including charging losses. At a home domestic rate of about ₹6.50–7 per unit all-in, that is roughly ₹1 per km, compared with ₹6–8 per km for a petrol car. Scooters use far less.
KERC has a separate EV charging tariff (LT-6c) that is lower than domestic. It needs a separate connection and meter for the charger, which makes sense mainly for public chargers, commercial fleets or apartments with shared charging, not for most single houses.
How many units it adds, and what happens to Gruha Jyothi
Work it out from your driving. A family that drives about 1,200 km a month in a car using 15 units per 100 km adds about 180 units a month. At roughly ₹6.5 a unit with charges and tax, that is about ₹1,170 a month. An e-scooter doing the same distance uses only a small fraction of that.
The bigger effect may be on Gruha Jyothi. The scheme does not apply in any month your consumption goes above 200 units, and then you pay for every unit, not just the extra. A home that used 150 units and had a zero bill can jump to well over 300 units with a car, and pay the full bill every month. Plan for that rather than discovering it on the first bill. Our appliance units guide helps you see where the rest of your units go, and the bill calculator shows the new monthly amount.
Charging from rooftop solar
An electric car is one of the best reasons to put up rooftop solar, because it turns a light-use home into one that pays a full bill. Each 180 units a month of driving needs about 1.5 kW of panels (180 ÷ 120).
- Daytime charging uses solar units directly. This suits people who work from home or have a second car that stays parked.
- Night charging still benefits under net metering, because units exported in the day are set off against units imported at night within the month.
- The subsidy cap is ₹78,000, reached at 3 kW. A house adding a car often ends up at 4–5 kW, so plan the sanctioned load for both the charger and the solar together.
Our PM Surya Ghar guide explains the application and sizing.
Electric scooters: small load, real fire risk
Two-wheeler chargers draw little power, so the load is rarely a problem. The risk is the lithium battery itself. Fires from scooter batteries charging overnight inside homes have been reported across India, and they spread fast.
- Charge in a ventilated parking area or balcony, not in a bedroom or next to the main door, which is your escape route.
- Use only the charger supplied with the scooter or an approved replacement. Cheap chargers do not stop at full charge.
- Plug into a fixed, earthed socket on a circuit with an RCCB. Do not run the charger from an extension board on the floor.
- Stop using a battery that is swollen, smells, gets very hot or was submerged during a flood.
- Do not leave a scooter charging unattended for many hours after it is full.
Tenants: the connection is in the owner's name, so agree with the owner before adding any charging point, and get any load enhancement done by the registered consumer.
Building or rewiring? Plan for a charger now
If you are building a house or redoing the wiring, provide for EV charging even if you have no electric vehicle yet. It costs little during construction and a lot afterwards.
- Run a spare conduit from the main distribution board to the parking wall, sized for a cable suitable for a 7.4 kW charger, with a pull wire inside.
- Leave a spare way in the distribution board, and make the board and service cable three-phase ready.
- Fix a weatherproof box at the parking spot at about chest height, clear of where water collects.
- Plan the earth pit for the charger at the same time as the house earthing, so it is tested with the rest before the connection inspection.
When the vehicle comes, the job is then a cable pull, a breaker and the charger, not chasing walls and digging up a finished driveway.
Apartments and gated communities
- Chargers in a flat's own parking slot can be fed from the flat's meter if the load allows, or from a separate EV connection.
- Common chargers for residents can be on a separate EV tariff connection, with billing to users.
- Plan the cable route, the transformer capacity and fire safety with the association before individual owners start installing chargers.
Government schemes and ESCOM rules are revised from time to time. This article explains how things work in practice. Before you act, confirm the current rule on the Seva Sindhu portal, your ESCOM website, your subdivision office or the helpline 1912.
Questions
Do I need permission from my ESCOM to install a home EV charger?
You do not need a separate permission if it runs within your sanctioned load from your own meter. If the charger pushes you over the sanctioned load, apply for load enhancement.
Can I charge an EV car from a normal 16 A socket?
A portable charger can use a dedicated, properly wired 16 A socket with good earthing. Do not use an extension cord or a shared socket circuit.
What RCCB is needed for an EV charger?
A Type B RCD, or a Type A RCCB if the charger has built-in DC fault detection. An ordinary Type AC RCCB may not trip on DC leakage.
Is there a cheaper EV tariff in Karnataka?
Yes, KERC has an EV charging category with a lower energy rate, but it requires a separate connection and meter. Most homes charge on the domestic meter.
How long does a 7.4 kW home charger take to charge a car?
Roughly the battery size in kWh divided by about 7, so a 40 kWh battery takes around six hours from nearly empty. If the car's on-board charger accepts only 3.3 kW, it charges at that rate whatever wall box you fit.
Will charging an EV at home make me lose Gruha Jyothi?
Only in months when total use goes above 200 units. In those months the scheme does not apply and you pay for every unit. A car adding 150 to 300 units a month often pushes a house over that limit.
Can a tenant install an EV charger?
Only with the owner's agreement. The connection and sanctioned load are in the owner's name, so any load enhancement has to be applied for by the registered consumer.
Need this done for you?
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