kW vs kWh: What's the Difference? (EV Guide)

The single most useful thing to understand about EVs is the difference between kW and kWh, because nearly everything about charging and running costs comes back to it. In one line: kW is power, how fast energy moves, and kWh is energy, how much you have. Mixing them up is the root of most charging confusion, so here is the simple version.

The bucket and tap analogy

Imagine filling a bucket from a tap.

• kW (kilowatts) is the tap's flow rate — how fast the water comes out. A bigger tap fills faster.
• kWh (kilowatt-hours) is the amount of water — how much is actually in the bucket.

A charger rated at a higher kW fills your battery faster. A battery with more kWh holds more energy, so it goes further. One is about speed; the other is about size.

What does kW mean for charging?

kW tells you how fast a charger delivers energy, so it sets your charging speed.

• A slow home charger might deliver a few kW, perfect for topping up overnight.
• A public DC fast charger delivers many more kW, so it adds range quickly on a trip.

The higher the kW, the faster the fill, up to what your car can accept. This is why fast chargers are for trips and slower home charging is the cheap everyday default, a trade-off our guide to EV charging costs breaks down.

What does kWh mean for your car and your bill?

kWh measures energy, and it shows up in two important places.

• Your battery size. A battery rated at, say, 50 kWh holds that much energy. A bigger kWh battery generally means more range.
• Your electricity bill. Meralco bills you per kWh, at roughly ₱11 to ₱13 per kWh on a typical home tariff. So charging that adds, for example, 10 kWh costs about ₱110 to ₱130 at home.

This is why you can estimate a charge's cost with simple multiplication: energy added in kWh times your rate per kWh. Our guide to EV charging costs works through real examples.

How do kW and kWh work together?

They connect through time. Power (kW) applied over time gives you energy (kWh). A charger delivering 10 kW for one hour delivers 10 kWh. So a faster charger (more kW) puts the same energy (kWh) into your battery in less time. That is the whole relationship, and once it clicks, charging speeds and costs stop being mysterious. You can see it in action with our charging time calculator, and the EV glossary defines the related terms.

Frequently asked questions

Is kW or kWh more important?

Both, for different things. kW (power) determines how fast you charge; kWh (energy) determines how much your battery holds and how much your charging costs. You need both to understand EV charging.

How do I know how much a charge will cost?

Multiply the energy you add, in kWh, by your electricity rate per kWh. At a home rate of roughly ₱11 to ₱13 per kWh, adding 20 kWh costs about ₱220 to ₱260. Our charging cost guide shows full examples.

Does a higher-kW charger damage my battery?

No. Your car only accepts as much power as it is designed to, regardless of the charger's maximum. Faster charging generates more heat, which is why using slower charging day to day and fast charging for trips is a gentle habit.

Why does my bill show kWh but chargers show kW?

Because your bill measures energy used (kWh), while a charger's rating describes how fast it delivers that energy (kW). They are two sides of the same coin, linked by time.