EV battery maintenance 101: Avoiding lazy batteries

We love our scooters. We keep them covered in the rain, lock them up at night to keep them safe from thieves and give them a nice cleaning from time to time. In turn, our scooters are good to us, allowing us to leave the office as fast as possible at exactly 5 pm on a Friday or make a quick getaway when we spot an ex. 

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But there’s an important part of our scooters that often goes overlooked. Despite the fact that batteries are what keep our electric scooters powered up and running, we often forget to show them the love they deserve. 

The problem is, there’s so much conflicting information out there. To sort through the noise, we spoke with our team of in-house battery experts about how to keep your EV batteries happy and healthy.

First, let’s start with the basics:

The science behind how your batteries work

Think of your batteries like an hourglass. One side contains graphite, while the other contains lithium. As the lithium ions in your battery are used up and depleted, they move from the lithium side to the graphite side of your battery. When you charge it back up, the process simply reverses.  

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Because lithium ion batteries rely on this shift in ions (rather than a chemical reaction like in older nickel based batteries), they degrade much more slowly and are able to survive thousands vs hundreds of charge cycles. Their greater powering capacity also make it possible for these relatively lightweight batteries to power high energy consuming products like electric vehicles. 

Read more about how lithium ion batteries were developed and why the scientists behind this technology were awarded the 2019 Nobel Prize for Chemistry.

What’s the average life expectancy of your scooter’s battery?

That depends on how well you maintain it. If you take care of your battery, it could actually outlive your scooter. 

The truth is, an electric scooter is not the same as a car which is built to go faster and have the capacity to drive farther. Different factors including the distances you drive, speed, terrain, weather conditions, etc. will all impact the lifetime of your scooter but, on average, most last for plus or minus 25,000 – 30,000 km (much less than a car).

Your battery, on the other hand, has a life of its own. Tucked inside the safety of your scooter’s outer shell, it will experience less external wear and tear from the elements than your scooter itself. But, despite this relative protection, if you fail to maintain your battery properly, it could burn out within a year. 

When it comes to batteries, it’s all about maintaining the internal dynamics. By following proper charging, discharging and storage practices, your battery could outlive you… ok, maybe not, but close. 

Check out these common questions, myths and best practices:

Does overcharging impact your EV battery’s lifespan?

What better way to take care of your batteries than to always keep them fully charged up, right? Not according to one of our battery experts, Joris Koudis:

Meet Joris Koudis, one of the innovators behind Etergo's AppScooter. It's not just electric, it's better in every way.

Charging your battery all the way to the top is going to take the most wear and tear out of it. Usually you would charge a battery to 4.2 volts, that is more or less what every single battery cell can actually do. But if you charge it up to 4.25 volts (so just five hundredths of a volt extra), that will already reduce the lifetime value by a very significant amount. So this is really a bit of an upper limit. After that it’s a bit of a cliff where you start with a lot of wear on the battery.

Like a student during exam week, pumping your body full of coffee and Red Bull may give you the hyperactive energy you need to get through an all night study session, but doing this every night will cause significant damage to your body over time. 

This doesn’t mean that you have to strictly adhere to the commonly cited ‘charge up to 80% and discharge down to 20%’ rule of thumb. He assured us that you can still charge up to about 98% without causing damage to your battery. 

You also don’t have to stress about leaving your battery plugged in overnight. By design our charger and battery actively prevent voltage levels that cause excessive wear, allowing you to maintain the life of your battery, without even having to think about it. 

So, to sum up, it’s ok to fully charge up your batteries overnight but try not to leave them plugged in for longer than that. 

Checking out the AppScooter's patented EV battery.
Prince Constantijn of the Netherlands checking out AppScooter at CES Vegas 2019

How long does it take to charge an EV battery?

Just like you shouldn’t charge up to the maximum level, charging too fast can also damage your batteries. Recently, a team of scientists at Purdue University discovered that fast charging batteries may actually degrade at a faster rate. Despite the fact that they’re equipped with thicker electrodes, faster moving ions simply break down electrode particles at an accelerated rate.

Evidence that (in the battery world) size isn’t everything, project lead and assistant professor of mechanical engineering Kejie Zhao explained, 

The capacity of batteries doesn’t depend on how many particles are in the battery; what matters is how the lithium ions are used.

That’s why it takes between 2.5 – 5.5 hours to charge up the batteries of your electric scooter. 

Check out this cool video about how Zhao’s team is using 3D models to better understand how batteries work internally:

Should you let your battery drain down to 0% once in a while?

You may have heard that letting your phone or computer completely drain from time to time is actually good for your device. 

The truth is that older battery types like nickel-cadmium and nickel-metal hydrides can sometimes develop what’s called a ‘memory effect’. This happens when a battery is only partially discharged and then recharged again, and then essentially ‘forgets’ it has a greater charge/discharge capacity.

Unlike other types of batteries, lithium ion batteries don’t suffer from the memory effect and, in fact, letting them deplete down to 0% could have deadly consequences for your battery. 

This is a no go according to Joris: “If you completely deplete a lithium ion battery, you should not  try to recharge it. Strictly speaking you can but it comes with a very serious safety risk and sometimes it will not work at all.” For example, our Battery Management System won’t let users recharge batteries that have been completely drained in order to ensure safety. 

Will my batteries hold their charge when I’m not using them?

Even if you don’t completely drain your battery, keep in mind that it will still lose charge, even when not in use. 

In this sense, our batteries work similar to our bodies. When you work out, you deplete your energy levels faster than if you spend your day lazing in front of Netflix… But that doesn’t mean you don’t expend energy. Even if you’ve shamelessly buried your gym card somewhere at the bottom of your random things drawer, your energy is still being used up, just at a slower rate. 

According to Joris:

At the end of summer, let’s say you track your scooter until it’s almost completely empty. If you’re then going to store it over winter, most likely after winter you can throw away your battery. You should make sure your battery always has some charge in it. 

The same goes for your electronic devices. If you leave them in a drawer for a couple of years and you try to charge them up, they’ll only hold a very small charge. It’s because they’ve been at such a low charge for so long. So that will be a big user influence on battery life.

Of course running down to the last dredges of your battery can sometimes happen. 

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If it does, here’s a tip from one of our awesome Etergo forum members:

“Try to avoid full discharge if you don’t charge immediately afterwards. And don’t charge to 100% if you will leave it there for multiple days,” said Jean.

What are some best practices for maintaining your battery during short/long term storage?

Etergo service engineer, Javier Franzoni, shared some of his tips for maintaining your battery during both short and long term storage of your scooter:

Keep the AppScooter in a flat, steady, well-ventilated and dry area. If necessary, protect it against dust with a porous cover. Charge the battery to 50% full before storage to maximize battery life. Avoid exposure under sunlight and rain to reduce damage or aging.

Remember to have a charge and a discharge at least every 2 months. Charge the battery to 100% full after long-term storage.

Joris agreed explaining that:

Charging to 50% has turned out to be a bit of a sweet spot. If you store it at higher voltages, it will actually deplete faster. But if you start more or less halfway down, it will deplete really slowly. In addition to that, it’s also safer to store it at a lower state of charge.

What happens to your EV batteries in cold/warm weather?

Extreme weather is your battery’s kryptonite. Lithium ion batteries start to degrade if stored at extremely low (<0C) or high temperatures (>45C). Keep this tip from Joris in mind:

If you’ve parked your scooter out in the sun on a hot day, there’s not a lot of room for the scooter to dissipate heat. This is because, when it’s stationary there isn’t going to be any driving wind and it’s going to be very concealed. This may cause the battery to heat up more during charging which then creates more wear. 

AppScooter's EV batteries are easy to carry and charge at home.

Just like you like to stay nice and toasty indoors on a cold winter day, so do your batteries. 

If your scooter is parked outside below zero degrees, it will not even be allowed to charge. So in both cases, it would be beneficial to charge the battery inside.

Another Etergo battery expert, Loek Marquenie, added:

What a customer can do is make sure his/her batteries are placed in a cool environment after heavy use, when they’ve become hot.

So, in practice, this means that on a very hot day after a long drive, they should not leave the battery sitting inside the scooter, but take it out and leave it inside a room somewhere. Otherwise the battery will stay at an elevated temperature for much longer, a situation that favours the unwanted chemical reactions that cause capacity loss.

Will using more than one battery pack while driving help prolong the overall lifetime of my batteries? 

Some EVs are equipped with one large battery pack, while others (like the AppScooter) can be powered by multiple packs – depending on the driving habits of the user. But does having one versus two, or even three battery packs make a difference when it comes to longevity?

According to Joris, the benefit of having more than one battery is that you’ll take less energy out of each individual pack. This means that:

1. Your batteries will experience less wear and tear 

Let’s say you bought your appscooter with a single battery and you charge this every 50 km for 30,000 km. You will then end up with about 600 charge cycles. This is already very achievable for any modern lithium battery. 

If, however, you decide to buy your appscooter with two or three batteries you may only charge it every 100 or 150 km for 30,000 km. This means that, in the same total distance, every pack will have only endured about 200 – 300 cycles which is very comfortable for any battery,” he explained.

2. You can reduce the overheating that comes with using just one energy source

Assuming you drive the same distance and speed, three battery packs will remain cooler during operation. Because they spread the heat evenly across all three, they have more heat rejection and they generate a bit less heat because, combined, they have less internal resistance. I think, if you expect to drive a lot of kilometres, three battery packs will definitely help you out.

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With these tips in mind you’ll have the basics you need to give your batteries a long, happy and healthy life. We love questions, so if you’re an investor or pre-order customer, please drop by our forum and let us know what you’d like to learn next about our batteries or the AppScooter in general. If you’re not a part of the Etergo community, we’re happy to share our insights on all your EV related questions on social.

Read more about the AppScooter’s batteries:

Charging your electric scooter’s battery has never been so easy. Find out more.

Learn more about our battery’s unique patented design and how it improves the handling of your scooter. 

Find out more about the evolution and improvements we’ve added to our batteries over time.

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