Why does my EV charge quickly, then slow down?
It's because your EV charges fast at first. Then the EV charging curve reduces the charging speed after your battery’s 50% full.
You arrive at a chargepoint and plug in. Your EV starts charging quickly.
You think you’ll be done in no time, but as your battery tops up, you notice it starts to charge slower. That’s the curve, at work.
What is the EV charging curve?
Your battery charges fastest when it’s relatively empty. As it fills, your EV gradually reduces the charging speed to protect battery health.
This change in charging speed is known as the charging curve. It’s a normal part of EVs.
How does it work?
Many EVs begin to slow their charging speed once the battery is more than halfway full.
Once your battery reaches 50% charge, it gets hotter and more energy is lost as heat, instead of being stored. The cooling system also needs to work harder to keep the battery within a safe temperature range.
After 80% charge, charging slows down more quickly to compensate for the above. That’s why the end of your session can feel like a lifetime.
What affects charging speed?
It’s affected by a few factors, like which chargepoint and charging speed you’re using.
Charging speed also depends on:
- Which EV you have
- How full your battery is
- The temperature outside
Using a rapid or ultra rapid charger? When charging speeds are high, your EV is more likely to reduce the charging speed near the end of your charge.
How to make the most of it on long journeys
The EV charging curve matters more on long journeys. Here’s how to use it to your advantage:
Arrive with a low battery
You’re on the motorway and you notice your battery’s dropped to 23%. It’s time to plan your next charging stop.
If practical, arriving with around 20% charge lets you make the most of the fastest part of the charging curve.
Try short charging sessions
Several short charging stops are often quicker than waiting for one long charge to reach 100%. You’ll save yourself time and keep your battery healthy.
Over several charging stops, that time you’ve saved builds up. You could arrive at your destination sooner, in plenty of time for that get together.
Set your limit to 80%
In many EVs you can pre-set your charge to stop once it reaches a certain amount. Set yours to 80%, so you never go over.
Use your EV’s touchscreen to set this limit. Or use the manufacturer or home chargepoint app.
Should I charge to 100%?
Charge to 100% when you need extra range, like before a long journey. For everyday driving, keeping your battery charged between 20% and 80% to function at its best.
How the Motability Scheme can help
We help you stay confident when you’re charging your Scheme EV both at home and on the go. Check EV for me hub to see useful guides and tips on driving an EV.
You can also use our:
- Go app: find and pay for over 80,000 UK public chargepoints
- Range calculator: see how far any EV can travel, under different conditions
- Route planner: plan your long journeys, including real-time chargepoint availability and prices
Use our tools to keep your charging sessions efficient.
Next time you’re heading out on a long journey, remember waiting longer does not always get you there sooner.
