One of the major concerns (if not THE major concern!) when switching over from a petrol- or diesel-powered vehicle to a battery-powered vehicle is how far you can travel between battery recharges.
Here is what we have learned so far….
Forget the old ‘petrol mindset’ of regularly stopping off at service stations to top up your energy supply – we do most of our car battery charging at home.
Commercial charging stations – in shopping centres, etc – are handy if we are travelling away from our local area for an extended trip, but otherwise each time we return home we plug the car in.
Just like our mobile phone.
We are all familiar with our current vehicle’s fuel tank capacity (litres), and rate of fuel consumption (litres per 100 km) – a combination of which determines how far we can drive a petrol or diesel powered vehicle before we need to refill the fuel tank.
Electric cars are much the same – except instead of a fuel tank EVs consume energy from a battery. The energy capacity of a battery is measured in kilowatt hours (kWh). The vehicle’s rate of energy consumption is measured in kWh per 100 kms.
Most EV’s energy consumption is around 15-18 kWh/100kms. If your battery has a capacity of 45 kWh, it can supply 15 kW per hour for 3 hours. If your battery has a capacity of 60 kWh, it can supply 15 kW per hour for 4 hours.
Battery capacity reality
Let’s say your petrol or diesel powered vehicle has a fuel tank with a capacity of 60 litres. Which means a usable capacity of around 50 litres – you don’t want to drain it to completely empty (especially if it is a diesel vehicle).
If you are using 8 litres of fuel to travel 100 kms, a journey of 750 kms would completely empty your 60 litre tank – and leave you stranded beside the road! If you play it safe and plan on using only 50 litres of your capacity (keeping 10 litres in reserve) you have a range of around 630 kms between refills. A refill of petrol or diesel only takes around 5 minutes at a service station.
The Lithium batteries that provide the energy supply for electric vehicles are much the same. You should work on using only 80% of their total capacity – charging to 90%, discharging to 10% – rather than using the full 100% of capacity. This will result in a longer battery life-span.
And of course, the other big factor to consider when ‘refilling’ your battery is that it takes a lot longer than 5 minutes – maybe 45 minutes for a full recharge of a 45 kWh battery using a 50 kWh charger. Less for just a ‘top-up’. Charging takes a longer time using a slower charging station.
Reality check? We have installed a 7kW wall charger at home. We rarely need to use a commercial charger – just plug in and recharge the battery overnight while we are asleep. For us, battery capacity really isn’t an issue in general daily use conditions. Just plug the car in when we arrive home. (Here is a ‘bonus’ of having an EV with a smaller battery – we can pretty much fully charge our battery in our 6 hour overnight EV-discounted charging period.)
Driving an EV at low speed consumes less stored battery energy than when driving at higher speeds – just the opposite of when comparing the fuel consumption of a petrol or diesel-powered car around town to driving on the highway.
At speeds under 80 km/h an EV will be consuming around 15 kWh of battery capacity every 100 kms, increasing to maybe 18 kWh per 100 kms at freeway speeds.
Around town, at lower speeds, consuming around 15 kWh per 100 kms, and allowing for the 80% rule……
- An EV with a 45 kWh battery will have a range of around 250kms before needing to recharge;
- An EV with a 75 kWh battery will have a range of around around 380 kms before needing to recharge.
Out on the highway, at higher speeds, consuming around 18 kWh per 100 kms, and allowing for the 80% rule…..
- Expect around a 200 km range from an EV with a 45 kWh battery, before needing a recharge;
- Expect around 330 km range from an EV with a 75 kWh battery, before needing a recharge.
And all of the above is very much an average. Everything depends on how hard you push that accelerator pedal, if you are travelling up hills, or down hills, if you have regenerative braking turned on, if you are using air conditioning, or heating, if you have a large load, how much charge you have in your battery before you leave, etc, etc.
With the above in mind, consider the figures below as a rough guide only….
Battery range and charge time (EVs in Australia 2023)
- The list below is not comprehensive;
- Battery size is based on manufacturer website specs;
- Usable kWh is based on 90% capacity;
- WLTP – The Worldwide Harmonised Light Vehicle Test Procedure measures the theoretical range of a car travelling at an average speed of 48 kmh in summer, with no heating or cooling systems running;
- ‘Around Town’ Real Range is calculated on 16 kWh / 100 km using 90% battery capacity;
- ‘Highway’ Real Range is calculated on 18 kWh / 100 km using 90% battery capacity;
- Charge rate is based on an actual ‘at home’ rate of 7kW.