This Is the Right Way to Charge, Discharge, and Store E-Moto Batteries

What is an electric dirt bike battery?

Everyday life is full of lithium batteries. If you’re reading this on your cell phone or laptop – yep, lithium battery! Since about 1991, Lithium Ion has been storing the electrical energy needed to power everything from portable electronics to electric cars and bikes. Regarding e-moto use, think of your battery as the gas tank in your traditional dirt bike. It is what provides the energy that converts to a fun day out!

Without going into a complete science lesson, lithium batteries, like the one in your Surron, are made from hundreds of cells. Each cell resembles a standard-looking AA battery, which all combine to create one big battery. The magic that happens inside each cell is due to lithium ions moving from the positive electrode to the negative electrode and vice versa, depending on whether the battery is being charged or discharged. Watch this video here if you’re interested in learning more:

What is important to note is the fact that your battery has lots of packed-in energy. It has to, to provide the high-performance power behind the throttle. That’s why it’s important to know how to take care of your e-moto’s precious battery, because if something goes wrong, it can go wrong in a big way.

What Causes E-Bike Battery Fires?

Any e-moto rider’s biggest fear is an idle battery catching fire in the garage or workshop, completely destroying the battery itself and possibly the bike or whatever building it was in at the time. Just look at any news article regarding lithium battery fires. But what really is the reason behind the fires? 

In 2022, the New York Fire Department reported 92 fires started from e-bikes and similar devices in the first half of the year.¹ This also resulted in 9 fatalities. And while any number greater than 0 for either figure is a tragedy, considering just how many e-bikes and e-motos there are in that area – easily thousands – we can safely conclude that the statistical likelihood of a battery fire was low in that area during that time.

Nonetheless, you should take every precaution to make sure it doesn’t happen to you. Let’s look into why lithium battery fires start; then, we can determine how to prevent or minimize any risk. 

Thermal runaway

Lithium-ion batteries can catch fire if a short circuit occurs due to a malfunction, or if they are overcharged or get too hot. The battery will heat up to a dangerous level, and a ‘thermal runaway’ will occur – rapidly heating with a fire or explosion shortly after. The Battery Management System (BMS), integral to the battery, should prevent overcharging or provide a cut-off if the battery overheats. Whether the BMS does its job at that moment or not largely depends on the quality and condition of the BMS itself.

Remember I said there are many cells inside a battery? If one of those cells overheats and goes into thermal runaway, it will quickly trigger the cells around it to also overheat. For this reason, lithium batteries will have multiple ‘explosions.’ This video shows how individual cells can trigger further fires.

Needless to say, if your battery catches fire, don’t be fooled into thinking the fire is out, and don’t move it with your hands! 

Are electric bike batteries a fire risk?

With all this doom and gloom, it could be easy to conclude that lithium batteries are dangerous. Yes, they can be, but there’s usually more to the story… With a reputable battery, proper care and maintenance, you can minimize the likelihood of a battery fire happening to you. 

Additionally, US Senator Kirsten Gillibrand stated  “Let me be clear: most lithium-ion batteries are safe. Those that are certified have a safety tool built in to prevent overheating and malfunctions like all of our iPhones have. We must encourage the use of more sustainable transportation alternatives, but we can’t allow for faulty or improperly manufactured batteries that keep causing these dangerous deadly fires.”² This indicates that, generally speaking, it is faulty or improperly manufactured batteries that are the most at risk. 

The FDNY suggests the following:³

• Purchase your battery from a reputable company. These companies have strict policies to follow to ensure manufacturing is at a high standard and meets all guidelines.
• Be cautious about purchasing a secondhand battery.
• Follow the instructions for charging your battery carefully.
  • Always charge using the charger provided with the battery, look for any signs of damage, and don’t use it if anything appears out of the ordinary. If you need to replace the charger, purchase one from an authorized seller from the manufacturer. Also, check that it is compatible with your battery. 
  • Charge at the correct temperature. Surron states it is ‘prohibited to charge the battery in the temperature below 0 degrees Celsius.’⁴
  • Don’t charge if any of the connections are wet
  • Don’t charge overnight or leave it unattended. 
  • Don’t charge in an exit or near a door. (If you need to escape, you don’t want the fire blocking your exit!)
• Dispose of an old battery correctly. https://www.call2recycle.org/ is an excellent place to start (not affiliated). 

Sources
1. FDNY: Lithium-ion battery fires
2. Senator Kirsten Gillibrand comments on lithium battery safety in Habitat Magazine
3. FDNY Foundation guidelines on lithium battery safety
4. Surron LBX official owner’s manual (PDF)

Aftermarket Batteries and Battery Modifications

The allure of swapping the stock battery for something bigger with more output is high on many riders’ lists. And why not? Many reputable battery companies are creating batteries specific to e-motos. But the same rules apply: always buy from a reputable company and follow their instructions. If you’re not sure what to do, then ask! 

You’ve also probably seen how to bypass stock batteries to increase power; a quick search will show many articles and YouTube videos of other riders doing that. While we’re all for max power and exhilarating fun, we’re also for not doing something stupid when mucking around with high-performance energy storage devices. Do your research first. Not everyone is qualified to give advice, and while you may be able to pull more power from your battery, you run the risk of damage if not done correctly. That damage might not appear for a few rides after vibrations come in and things start to short-circuit. Damage could be a battery that no longer charges, but it could also be a battery that catches fire. Not good. Also, keep in mind that ‘cutting that wire’ is not as risky as tinkering with the internals of a battery – let’s limit this discussion to the internals of a battery and talk about ‘that wire’ later. 

E-Moto battery care

Replacement stock batteries are upwards of $1600, and aftermarket batteries can be much more than that. Not only is it a good idea to look after your battery from a safety perspective, but it also saves you a few dollars. The battery in your e-moto isn’t hard to look after; a few simple tips will prolong the life of your power supply. 

All sources I have encountered on the interwebs state that modern lithium-ion batteries should be good for 500-1000 charge cycles if correctly looked after. To be clear, a ‘charge cycle’ is from, effectively, empty to full. So, if you only use 50% of the battery on a ride, that’s only half a charge cycle.

Of course, any knowledge of a battery’s history goes out the window if you buy it secondhand. It’s a common thing to see people selling their stock Surron or Talaria battery after buying a new or upgraded battery, but a battery can look perfectly fine on the outside and be damaged on the inside. We suggest using caution if you plan to buy a used battery secondhand – there are ways to test a used battery to make sure it’s within spec, but to eliminate any guesswork, buy new if you can afford to.

What if the battery has had damage? 

Ok, so e-motos are dirt bikes… and there is a high chance that it will end up on its side, or as I’ve had before, in a tree (don’t ask, I still don’t know how I did that… it was hilly terrain…) But if you damage a gas tank, it’s pretty obvious, and if the smell won’t allude to the issue, then a coughing motor will. How does it work with batteries?

I checked with Rusty, GritShift’s R&D guru and experienced e-moto rider, for what he would advise, and he said: “As long as your battery fits into your bike properly, a crash should not damage a battery. Most batteries are enclosed in an aluminum/steel case of some sort and sit inside of the frame rails.”

He mentioned that the battery would likely be OK unless there was apparent damage. If you’re unsure, then the battery manufacturer would be your first point of call to see what they can advise.

How to charge, discharge, and store an e-moto battery

Charging

Just plug it in, right? Not so fast! The best answer is to use the charger that came with the battery. This is important as it will provide the ideal voltage and current and help prevent overcharging. Overcharging can also occur if there is a fault within the battery BMS, either from manufacturing, damage, or tampering. Simply put, the electricity will continue to try to flow into the battery, which will cause excessive heat generation. From here, the real danger of thermal runaway is a likely outcome. Lishen, a Lithium-ion battery R&D firm and manufacturer, recommends always unplugging your charger when the battery reaches 100% in this article here. And as we will cover in a moment, waiting until the battery reaches room temperature before charging is recommended to get the best life span possible.

Discharging

To prolong the life of the battery, it is also recommended to recharge your battery before it reaches a critically low level. Discharging no lower than 20-30% remaining is ideal. If your machine gives you live battery temperature data, be sure to keep an eye on that and respect the low and high limits set by the battery manufacturer.

Infrequent use

Like anything, if used regularly, your battery will perform at its best. I can even talk about myself with my riding! Nothing like feeling out of form when you can’t get to the track for weeks. Anyway, I digress – if you need to store your battery for a while, it is suggested that the battery be left at around 50% to 60% charge and stored in a cool, dry location with a humidity level of 50% or less. Every three months in storage, check the battery and, if needed, charge it to 60%. The team at GritShift give their e-moto batteries constant workouts! However, the only times we’ve had batteries fail to charge is when they’ve been left in storage at an incorrect percentage for over a year. I guess the moral to this story is to get out and ride more so you don’t need to store your batteries!

Temperature and batteries

Surron says, ‘If the temperature ranges from 50 to 86 degrees Fahrenheit (10°C to 30°C), the battery will have its best performance.’ If the temperature is outside this range, the performance will be degraded. Surron also states that charging the battery below 32°F (0°C) is prohibited. On the other hand, if you live somewhere like I do, where temps can reach over 100°F (38°C), you also need to be aware of the working temperature range and the charging temperature range. Surron states not to ride over 122°F (50°C) – why would you want to anyway! But seriously, at any ambient temperature, waiting until the battery reaches room temperature before charging is recommended to get the best life span possible.

TLDR: Respect Your Batteries

• Charge your battery to 100%, then remove it from the charger
• Run your battery no lower than 20-30% before recharging
• Let your battery reach room temperature before charging
• If you store your battery for a long time, keep it at about 60% charge
• Always store your battery in a cool, dry area with low humidity
• Don’t try to internally modify your battery unless you are a professional

Lithium batteries are amazing! They provide instant acceleration that is unlike piston power. They hold a vast amount of energy just waiting to be released, which powers a massive range of items – electric dirt bikes being one of them. The same guidelines apply to any gadget powered by lithium batteries.

You might have noticed we didn’t say much about keeping your battery clean cosmetically. Although keeping the terminals clean is important, e-motos generally do a pretty good job of protecting their batteries from the elements, and the manufacturers do a great job of wrapping the battery in multiple layers of protective material. In short, dirt and grime on the outside of the battery won’t amount to much – it’s what’s inside that matters most.

The dangers you hear about are real, but your battery will last a long time with the proper care and common sense. Don’t forget that, typically, there is more to the story than ‘just’ an e-bike battery catching fire – has it been damaged or not made by a reputable company? Was it modified beyond its original design? Was it overheated on a regular basis by somebody who didn’t know any better? If you purchase a new battery, ensure it is from a reputable company or that you know the history of buying second-hand.

Look after your battery by recharging it before it gets ridiculously low, storing it correctly when not in use, and watching the charging temperature range. If you have concerns about your battery’s health, consult the manufacturer for advice. Under the proper commonsense care, your battery will provide the exhilarating acceleration you need for a long time.