Tips for Charging Electric Cars in Hot Weather

Does heat affect electric cars?

Although it’s perfectly safe to drive in hot conditions, EV drivers are understandably concerned with the effect of extreme heat on their car’s lithium-ion battery.

From a technical standpoint, electric car batteries are less efficient when it’s hotter as the heat affects the battery’s power output, which translate to a lower-than-usual driving range. If exposed to high temperatures frequently, or significant periods of time, this can further result in reduced energy storage capacity, giving the battery a permanently shorter range.

High temperatures also slow the rate at which your EV battery can charge, because heat slows down the battery’s internal processes – whether you’re discharging (i.e. driving) or storing (i.e. charging) energy. However, it’s still safe to charge when it’s hot, even on a rapid-charger.

Modern electric cars are equipped to deal with hot temperatures

Like most concerns about EV driving, we tend to think of the early days of electric cars when the technology was still relatively new.

Thankfully, modern electric vehicles are worlds apart, coming equipped with advanced thermal management systems (TMS). This keeps the car within optimal temperatures, preventing overheating and maintaining performance in hot weather, by working with another system – the battery management system (BMS) - which monitors battery temperatures.

TMS includes the use of cooling pipes which circulate coolant fluid around key components of the car, including the battery and electric motors. Radiators can also be used to take the heat from the car away and into the surrounding air.

This doesn’t mean it’s unsafe to drive an older EV in hot weather. You just might see some loss in battery performance if you drive it frequently when it’s extremely hot, but again, that’s in temperatures of 35 °C+ which (in the UK at least) remains unlikely.

How hot is too hot for an EV battery, and what temperature is best for my EV?

The optimal ambient temperature for your EV sits at around 20 ° C to 25 °C (68 °F to 77 °F for our American readers). In this range, your car will be at its most efficient, giving you peak battery performance, driving range, and charging times.

Above 35 °C/95 °F is when any lithium-ion battery can start to overheat. Fortunately, in the UK at least, it’s still very rare for temperatures to exceed this, especially for long periods of time. Elsewhere in the world, it can regularly be this hot, but fortunately for us...

How to mitigate EV battery issues in hot weather

If you do need to drive on an extremely hot day, these are a few easy-to-follow tips that will help you avoid any issues with your EV:

Pre-condition your cabin before driving

Just like pre-heating your car’s cabin in cold weather, you could air condition the cabin whilst the EV is plugged into your home charger. This ensures your cabin is nice and cool once you set off, without using your battery and spending energy that could otherwise contribute to driving range or performance.

Reduce air conditioning and on-board infotainment usage

You’ll naturally want to keep your cabin cool whilst it’s hot, but using air conditioning constantly will eat into your driving range, which may already be lower due to the heat. That said, air conditioning uses less energy than heating during winter, and some modern EVs have more advanced systems that make air conditioning more efficient.

Plus, EV driving ranges tend to be significantly higher than the typical journey. Unless you’re going on a lengthy road trip, don’t sweat about using the AC! Similarly, any additional features like infotainment will reduce range, so where possible avoid using these.

Use eco mode

Eco driving modes can limit the power available for the electric motor, adjusting performance to conserve battery power such as by reducing acceleration levels in exchange for higher ranges.

Don’t drive too fast

A useful tip whether it’s hot or not, accelerating quickly or driving fast for prolonged periods of time can quickly eat away at your driving range. Driving smoothly will maximise your range.

Park in the shade

If you’re able to, park your EV in a shaded spot as this will help keep your battery (nice and cool naturally. This includes the cabin, meaning you won’t need to use as much energy on air conditioning straight away.

Check your tyre pressure

Whether you’re going on a long trip or not, a generally sound piece of advice is to always keep an eye on your tyres. Underinflated or worn-out tyres can make your electric car less efficient, giving you a less-than-optimal driving range. On the other hand, an overinflated tyre can affect the car’s handling and braking, so always make sure they’re at the right PSI.

Keep your car free of clutter

Excessive weight can result in a less efficient EV. Whilst it’s not a problem if you’re doing short trips in hot weather, it’s worth having a clear out of anything unnecessary if you’re planning a long trip on a hot day to squeeze out every mile possible.

Can you charge your EV in hot weather?

Summer heat isn’t dangerous for your home charger, with the heat on a normal summer’s day posing no risk at all to the charger. If it’s anything like the Pod Point Solo 3S, it will have been designed to withstand a wide range of weather conditions, including UK summers and occasional heatwaves. The Solo 3S in particular is safe to operate in temperatures of up to 50 °C.

There are some concerns that you shouldn’t use rapid chargers in hot weather. Whilst that may be true in the world’s hottest climates, in the UK it’s not a problem rapid charging in the summer. Even if you’re sweating from the heat, your EV’s TMS and BMS will keep your battery safe whilst charging.

Simply put: a bit of sunshine won’t stop you from charging your electric car, even on a really hot summer’s day!