Are E-Bike Batteries Damaged When Charged Too Long?

It may surprise you to learn that batteries that are meant to be rechargeable are actually quite sensitive.

Whether it is a cellphone battery, a car battery, or even an e-bike battery, there are plenty of ways to put a drain on the battery, which will shorten its lifespan.

One of the biggest ways to damage your battery is to overcharge it or even if you never let it fully charge.

So, what exactly happens to an e-bike battery when charged too long, and what is the best way to care for your battery to make it last?

Here is what we learned:

Here’s What Happens When You Overcharge an E-bike Battery:

Overcharging an e-bike battery will put a huge drain on the battery, which can shorten the number of years that the battery can be usable before it needs replacement. However, this is not the only way you can damage the battery by charging.

Do E-Bike Chargers Switch Off When Fully Charged?

Only a handful of e-bikes come with an internal switch that shuts off the power to the battery when the battery has reached a full charge. This works even if you leave your bike’s battery plugged in for an extended time.

Once the battery has reached a full charge, a signal will be sent to the charger to switch it off. This completely puts a stop to any power that is running to the battery.

However, this feature is only found on more advanced and expensive e-bikes that generally use lithium-style batteries.

The majority of e-bikes that you see on the market now do not have this feature.

This means that even if the battery has reached a full charge, power will continue to be flowing to the battery, which puts a lot of stress on it.

When you allow an e-bike battery to stay connected to the charger, the battery cycle will constantly switch on and off. Just the simple act of switching battery cycles can, over time, reduce the battery’s capacity for power.

So, over time you will find that your battery does not stay charged for as long as it used to and also may take much longer to charge up to a full battery.

E-bike batteries are meant to last up to 5 years before needing a replacement. Mistreating your battery during a charging cycle can reduce the battery’s life by up to 2 years, forcing you to purchase a newer battery early than expected.

It should also be noted that e-bike batteries can run up to $700 per replacement, so keep a close eye on your battery’s charging cycle unless you want to spend more than you have to.

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What Is The Most Optimal Charging Routine?

Now that you know the worst ways to charge your e-bike battery, it’s time to dive into what is the best way to charge your battery to extend its lifespan.

Most people think charging their e-bike battery overnight is the best way to ensure it will be full and ready for their next ride.

However, charging overnight usually means that the battery will be left plugged in and charging for up to 10 hours, depending on when you get up.

In order for an e-bike battery to reach full capacity and hold a full charge, it only needs 4-6 hours plugged in.

So, when you charge it up to 10 hours after the battery has reached full charge after 6 hours, it will spend those additional 4 hours switching the battery cycle on and off, which will stress the battery over time.

The best way to charge your e-bike battery to ensure you are not damaging it, in the long run, is to plan ahead.

For example, start charging the battery 6 hours before leaving if you plan on going for a ride.

For extra measure, set a charging timer on your phone for that exact amount of time so that you can be sure to swiftly disconnect the charger when the battery reaches full capacity.

If you need to charge your battery overnight to prepare for a long morning ride, you can purchase a timed power switch that will connect to the charger’s power source.

Set the time for 6 hours. Once it reaches 6 hours of charging time, the switch will engage, turning off power to the battery, ensuring it won’t be overcharged.

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Can You Leave Electric Bike Batteries Charging All Night?

As mentioned, you shouldn’t leave your electric bike battery charging overnight, but that doesn’t mean that you can’t.

Just understand that you are putting your battery under stress if you do this often. It should also be noted that occasionally leaving your battery charging overnight won’t do that much damage as long as it is only on certain occasions.

However, if you leave your battery to charge for an extended period of time overnight every time you charge your e-bike, you are could be doing damage.

By using a timed power switch or a timer to ensure that your battery isn’t charging for more than 6 hours at a time, you greatly reduce the risk of burning it out quicker than expected.

So, yes, you can leave your e-bike charging overnight.

Just ensure you are doing your best to reduce the overall charging time to help make your e-bike battery last five years before it needs a replacement.

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Is It Bad to Always Charge to 100%?

Keeping your e-bike battery constantly charged to 100% is not a great idea. This usually means that you are either overcharging your battery or charging your battery too often.

Most riders think that they need to charge their e-bike after every use. But that really isn’t the case. A 40% charge will still mean that the bike will ride perfectly fine as if it was charged for a full 100%.

Some experts suggest keeping your bike between the 20%-80% charge range or 40%-70%. It is suggested that you should not let your bike get to 0% and not overcharge it at 100%.

You should also avoid charging your battery for a short time to just give it a little charge to make it through your ride.

It is much better to fully charge the battery than to only charge it halfway.

Final Thoughts

There are several ways that you can strain your e-bike battery, which will result in having to replace it sooner than expected.

However, the most significant way that you can drain your battery is to not be careful when you are charging it.

So, always make sure to never leave it charging for more than 6 hours.

This is the best way to save a good chunk of money on replacement batteries and ensure that your battery is running at its full potential.

Please also check out my article about 8 electric bikes with dual-battery capability.

Sources:

Should I Charge My E-Bike After Every Ride?

How To Keep Your E-Bike Battery In Top Shape