An EV battery’s energy capacity is measured in kilowatt-hours (kWh)—the amount of power it can provide for an hour of continuous use. For example, the 2022 Tesla Model 3 RWD has a battery capacity of about 60-kWh, which means it can discharge up to 60 kilowatts over an hour—in tests, anyway.
A kiloWatt-hour is therefore 3.6 MJ. Batteries are usually rated in units of current times time. This does not directly tell you how much energy the battery can store, but can be a more useful value in deciding how long a circuit will run from a battery. For example, a car battery might be rated for 50 Ah.
10kWh from 12V batteries -> 833Ah capacity Or seventeen 50Ah car batteries in parallel You forgot the time aspect: your answer assumes the 10kW must be delivered for one hour. A single car battery can deliver 100..200A, so for a short time period 4 batteries might be enough. The question as framed does not have a time element.
The term ‘kWh’, or ‘kilowatt-hour’, signifies a ‘unit of electricity’. Electric car batteries store units of electricity, or kWh, and as you drive they get used up. The term ‘kW’, or ‘kilowatt’, refers to the power rating of charging points. 7.4 kW is normal for a home charger. Public chargers vary from 50 kW to 350 kW.
A 10-cell 18 V battery uses cells that each produce only 1.8 V. You connect them in series to produce a higher voltage useful for driving an electric motor. This gives a power output of 18 x 20 = 360 Watts. If the cells were reconnected in parallel (which is usually unsafe), You could produce 10 x 20 = 200 Amps but only at 1.8 V.
Let’s say you have an electric motor rated at 200 kilowatts (kW) at peak power output. If you ran that motor for 30 minutes you would use 100 kWh of energy — 200 multiplied by 0.5 (of an hour) equals 100 kWh. If how far your electric car can travel on one charge is important to you, as a general rule of thumb, you want an EV with a big battery.