CHARGING BASICS 107: Reason why some rapid chargers cutoff at 90% SoC | Is it to prevent battery life degradation? (2024)

FAQs

Is it OK to charge EV to 90? ›

There are two reasons: charging performance and battery longevity. Most of the time you should only charge an EV to 80% because charging rates slow down dramatically past the 80% mark. And two, the long-term health of your vehicle's battery pack is improved when kept below 100%.

Fast charging has little impact on battery capacity, battery health, or long-term loss of vehicle range. Several studies have been conducted to look for a potential link between fast charging and battery degradation. However, each study shows minimal overall impact on battery degradation.

You may find your battery only charges to 80% and then stops (or creeps up very slowly). This is because it can take as long to charge from 80-100% as it does getting from 0-80%. Solution: Lithium-ion batteries don't like to be fully charged or fully discharged.

But just like a big sugary snack, fast charging can sometimes be too much of a good thing. Charging your phone to 100% all the time, especially with a fast charger, can put more stress on the battery and shorten its lifespan. It's like stuffing your phone with too much energy, which can make it wear out faster.

If you really need the range, go up to 90-95%. Electric car batteries should not, generally, be charged to 100%. Long-term, this reduces the battery's longevity, and Tesla cars actually charge up to 90% by default.

Tesla to start charging extra if you charge past 90% at a busy Supercharger. It's called a "congestion fee". Tesla is taking another step to free up busy Supercharger stations for more users — and potentially make some extra dough in the process.

Fast charging generally tends to reduce a battery's life quicker than slow charging, so repeated usage of this technology may not be good for the battery's health. As a consequence, users may have to replace the battery pack sooner than those who primarily use slow charging.

Yes, you can use your smartphone while charging. There is no danger in using your phone while it's charging. When you use your phone while charging, the battery is charging at a slower rate than normal to allow enough power for the ongoing usage.

When using slow charging, the cycle life of the battery can usually reach more than 3,000 times. However, if it is always fast charging, the cycle life will be shortened to about a thousand times, or even lower. So slow charging vs fast charging are important to batteries life.

There may be times when you want or need to charge up your EV to get maximum range. But charging it to the max shouldn't be done every night. In general, the SOC for the battery in your electric car should be maintained between 30% to 80% capacity.

What happens if you charge your EV to 100%? ›

Keeping the state of battery charge, from 0 percent to 100 percent , also improves the performance of the battery life of your vehicle. Even though a full charge will give you the maximum operating time, it is never a good idea for the overall lifespan of your battery.

When it comes to charging your EV, aiming for an 80% maximum charge is better practise than charging all the way to 100%. This might not make much sense if you're new to the EV world, especially if you're used to charging things to 100%, like mobiles or laptops.

Fast charging is safe for your phone's battery and won't cause long-term damage. When you use a fast charger, your smartphone will only draw as much power as it can handle, preventing any overload.

Using a higher wattage charger does not harm the phone or affect its charging process negatively. The phone will only draw as much power as it requires, regardless of the charger's maximum output. Therefore, using a 120W charger to charge a 33W phone is perfectly safe and will not cause any damage.

So at what percentage should you charge your phone? The best practice for preserving phone battery health is to plug it in at around 20% and charge it up to 80-90%. This is especially important if you use fast charging, as charging from 0% will cause a lot of heat, and from 80% up, fast charging becomes less efficient.

When it comes to charging your EV, aiming for an 80% maximum charge is better practise than charging all the way to 100%. This might not make much sense if you're new to the EV world, especially if you're used to charging things to 100%, like mobiles or laptops.

If you don't need it 80% is fine. I drive 90 miles round trip to and from work so I usually charge to 90%. I have charged to 100% exactly once just to see what it was like. Never needed to do it again.

Take care of your battery

However, if the battery overheats, the charging speed could decrease, or charging could stop altogether as a safety measure. It's worth moving your car into a parking spot in the shade if you can, to avoid overheating – plus your EV could even lose charge if left out in the sun for too long.

OVERCHARGING

Never let your battery sit at 100% charge. Generally speaking, lithium-ion batteries do best when they operate in the 30%-80% charge range. Although it may take some extra planning, prolonging the time spent within that middle range may extend the life of your battery.