How often should I charge my EV to 100%? [You should know This]

Now why this question coming is, one is about when 100% charging is needed in your EV which needs to be figured considering your driving needs and another is how often will be good for the battery to charge 100% so that it won’t result in battery degradation.

And there is one more reason behind this question. I will discuss it later here. But Let’s first clear out the first two points.

Let’s dive into it.

When should you charge your EV to 100%?

OK, now irrespective of considering the battery health of your EV, when you’re going on long trips and don’t have enough time to charge in between the trip then you should charge your EV to 100% without worrying about battery health. 

If you are frequently on long road trips (covering 80 to 100+ miles a day or two), it is totally OK to charge your EV to 100% daily or every alternate day depending on your driving needs.

Before proceeding further let me give a little clarification on battery degradation.

Clarification about battery degradation – My two cents

Now, when it comes to battery degradation, as per me it is actually an overrated thing taking it too seriously. 

Do you know, EV batteries are high-voltage robust batteries made to last for a long. And even charging it 100% whenever needed won’t make much difference. 

Yes, even if your EV drives daily 100+ or 200+ miles and charging it daily or alternate days to 100%, it will last for long at least well around two decades on average before it goes down to considerable degradation. 

And even the second or third owner of any EV will still enjoy a good battery life. 

And remember battery degradation does not depend solely on charging to 100%. However, it is a factor but it’s a very small factor. There are many other things adding to battery degradation. And charging to 100% whenever needed won’t make much difference. 

So just clear your fear about charging it to 100% whenever needed, it doesn’t matter even if needed daily. 

But that doesn’t mean there are no best practices to follow. It can make some difference in battery’s total lifespan. If your driving needs are such that you can follow then you should follow. 

Ok, let’s look at that. 

How often is good to charge your EV to 100%? – Considering battery health

Now you know charging EV to 100% is not dangerous to battery health, even if charged daily. But by following a certain charging practice you can add some pennies to battery health increasing its total lifespan. 

Now, if you can follow the 20-80 rule of charging your EV then it’s best. That means, don’t let your EV’s charge level fall below 20% and don’t charge above 80%.

If you drive less than 70-80 miles a day, which most EV drivers fall into and a lot of EV users just drive less than 50 miles a day. If your driving needs are like that then it is very easy and best for you to follow this charging practice maintaining State of Charge between 20% and 80% in your EV.

In addition to this, if you can maintain charge level around 50% then it is again best (of one level above!). 

If you drive around 20 miles a day then it will be possible for you and also it will be best if you maintain around 50%. That means, say, around 10% to 20% ± to 50% whatever suits you.

Now, whichever charging practice you may follow, charging to 100% if needed when you are on long trips is perfectly fine.

In addition to that it is again good to charge to 100% weekly or twice a month. 

There is a reason behind this. The third reason that I was talking about at the beginning of this article.

So let’s look into the third reason now, why this question arises.

When your EV needs to charge 100%? – And Why?

Now as I said charging your EV to 100% once a week or once every two weeks is good for the battery. 

The reason is EVs come with Lithium-ion batteries and Lithium-ion battery cells go out of balance often. Different types of Li-ion batteries go off the balance with different frequencies.

Now what is meant by Li-ion batteries going off? It means the charge level in each cell of the battery goes uneven. Ideally, all cells should have equal charge levels. 

So when you see the battery level percentage in your EV showing that particular percentage of battery is charged, it means each cell of the battery is filled that many percentage out of 100% of storage capacity. Let’s your EV’s battery have 65% charge level then it means each battery cell is filled with 65% of potential energy out of 100% of total capacity. 

When battery cells go out of balance then certain cells will have a lower state of charge and others will have a higher state of charge. Not all have an equal state of charge.

When this happens, first thing you will see is the wrong estimation of battery percentage and remaining range estimation in your EV’s dashboard. You may or may not notice it depending on how small the measurement error is.

Due to cell imbalance, the Battery Management System (BMS) gets wrong estimation of charge level when measuring battery’s state of charge. And later on, that error will continue in showing you battery charge level.

It may show you let’s say 90% state of charge but after some time charge level may fall suddenly and it will show 20% charge remaining and so corresponding range. 

OR when you try to charge your EV to 100% it won’t charge fully. It will stop charging to any level below 100% and you will see a message that charging is complete in your EV’s dashboard.

To avoid this happening to you, you should charge your EV to 100% at a certain frequency. This is called battery cell balancing and BMS calibration.

So every week or twice a month it is best to charge your EV to 100%. Or do it at the earliest opportunity if you see some error in showing State of Charge or range estimation. It will take care of these things. 

Now I have come upon this frequency of charging to 100% weekly or twice a month depending on my driving habits. But mostly it will fall perfectly into place for all drivers. But you may need to figure out a bit for yourself, but it will anyway come to just little here and there.

However, if that doesn’t fix the issue then you have to carry out cell balancing and BMS calibration in a proper manner. 

The proper process to balance the battery cells and recalibrate the Battery Management System (BMS) is to let the battery level fall below 10% then let it remain there for 3-4 hours in deep sleep and then charge it back to 100%. 

But that’s about a special reason concerning cell balancing and BMS calibration which requires your EV to charge to 100%.

But mostly just charging 100% every week or every two weeks will take care of this thing.

Conclusion

So this was all about how often you should charge your EV to 100%. 

I have explained best practices to follow considering your driving needs, battery health and BMS calibration. 

I hope now you are 100% clear about when to charge your EV to 100%.

OK Then, see you in the next article!