Technical Guide: Electric Scooter Batteries

Electric scooter battery pack
Electric scooter battery pack | Credit: Kairi

In this technical guide, you’ll learn everything there is to know about electric scooter batteries, including types, capacity ratings, how to prolong battery life, and proper use and storage.

See our in-depth guide on how to charge an electric scooter for best practices to prolong battery life.

By Justin. Justin has a degree in engineering and is a cofounder of ESG. He has helped develop the technologies behind the ESG website and authors articles covering the science and technology around the technical aspects of electric scooters.

Electric Scooter Batteries

The battery is your electric scooter’s “fuel tank.” It stores the energy that is consumed by the DC motor, lights, controller, and other accessories.

Most electric scooters will have some type of lithium ion-based battery pack due to their excellent energy density and longevity. Many electric scooters for kids and other inexpensive models contain lead-acid batteries. In a scooter, the battery pack is made of individual cells and electronics called a battery management system which keeps it operating safely.


Bigger battery packs have more capacity, measured in watt hours, and will let an electric scooter travel further. However, they also increase the size and weight of the scooter — making it less portable. Additionally, batteries are one of the most expensive components of the scooter and overall cost increases accordingly.

Types of Batteries

18650 Li-ion cells, pictured above, make up an e-scooter’s battery pack | Credit: Wikimedia Commons under CC BY-SA 3.0.

E-scooter battery packs are made of many individual battery cells. More specifically, they are made of 18650 cells, a size classification for lithium ion (Li-Ion) batteries with 18 mm x 65 mm cylindrical dimensions.

Each 18650 cell in a battery pack is fairly unimpressive — generating an electric potential of ~3.6 volts (nominal) and having a capacity about 2.6 amp hours (2.6 A·h) or about 9.4 watt-hours (9.4 Wh).

Battery cells are operated from 3.0 volts (0% charge) up to 4.2 volts (100% charge).

Lithium Ion

Li-Ion batteries have excellent energy density, the amount of energy stored per their physical weight. They also have excellent longevity meaning that they can be discharged and recharged or “cycled” many times and still maintain their storage capacity.

Li-ion actually refers to many battery chemistries that involve the lithium ion.  Here is a short list below:

  • Lithium manganese oxide (LiMn2O4); aka: IMR, LMO, Li-manganese
  • Lithium manganese nickel (LiNiMnCoO2); aka INR, NMC
  • Lithium nickel cobalt aluminum oxide (LiNiCoAlO2); aka NCA, Li-aluminum
  • Lithium nickel cobalt oxide (LiCoO2); aka NCO
  • Lithium cobalt oxide (LiCoO2); aka ICR, LCO, Li-cobalt
  • Lithium iron phosphate (LiFePO4); aka IFR, LFP, Li-phosphate

Each of these battery chemistries represents a trade-off between safety, longevity, capacity, and current output.

Lithium Manganese (INR, NMC)

Fortunately, many quality electric scooters are using the INR battery chemistry — one of the safest chemistries. This battery gives high capacity and output current. The presence of manganese lowers the internal resistance of the battery, allowing high current output while maintaining low temperatures. Consequently, this reduces the chances of thermal runaway and fire.

Some electric scooters with INR chemistry include WePed GT 50e and Dualtron models.

Lead-acid

Lead-acid is a very old battery chemistry that is commonly found in cars and some larger electric vehicles, like golf carts. They are also found in some electric scooters; most notably, inexpensive children’s scooters from companies like Razor.

Lead-acid batteries have the benefit of being inexpensive, but suffer from having very poor energy density, meaning that they weigh a lot compared to the amount of energy they store. In comparison, Li-ion batteries have about 10X the energy density compared to lead-acid batteries.

Battery Packs

To build a battery pack with hundreds or thousands of watt hours of capacity, many individual 18650 Li-ion cells are assembled together into a brick-like structure. The brick-like battery pack is monitored and regulated by an electronic circuit called a battery management system (BMS), which controls the flow of electricity into and out of the battery.

Schematic diagram of batteries in parallel and series
Schematic diagram of parallel and series battery connections | Credit: Wikimedia Commons under CC BY-SA 3.0.

Individual cells in the battery pack are connected in series (end to end) which sums their voltage. This is how its possible to have scooters with 36 V, 48 V, 52 V, 60 V, or even larger battery packs.

These individual strands (many batteries in series) are then connected in parallel to increase output current.

By adjusting the number of cells in series and parallel, electric scooter manufacturers can increase output voltage or max current and amp hour capacity.

Changing the battery configuration will not increase total energy stored, but it effectively allows a battery to offer more range and lower voltage and vice versa.

Voltage and % Remaining

Each cell in a battery pack is generally operated from 3.0 volts (0% charge) all the way up to 4.2 volts (100% charge).

This means that a 36 V battery pack, (with 10 batteries in series) is operated from 30 V (0% charge) up to 42 volts (100% charge). You can see how % remaining corresponds with battery voltage (some scooters display this directly) for every type of battery in our battery voltage chart.

Voltage Sag

Every battery is going to suffer from a phenomenon called voltage sag.

Voltage sag is caused by several effects, including lithium-ion chemistry, temperature, and electrical resistance. It always results in non-linear behavior of the battery voltage.

As soon as a load is applied to the battery, the voltage will instantaneously drop. This effect can lead to incorrectly estimating battery capacity. If you were directly reading out battery voltage, you’d think you had instantly lost 10% of your capacity or more.

Once the load is removed the battery voltage will return to its true level.

Voltage sag also occurs during long discharge of the battery (such as during a long ride). The lithium chemistry in the battery takes some time to catch up with the discharge rate. This can result in the battery voltage dropping even more rapidly during the tail end of long ride.

If the battery is allowed to rest, it will return to its true and accurate voltage level.

Capacity Ratings

E-scooter battery capacity is rated in units of watt hours (abbreviated Wh), a measure of energy. This unit is quite easy to understand. For example, a battery with a 1 Wh rating stores sufficient energy to supply one watt of power for one hour.

More energy capacity means higher battery watt hours which translates to longer electric scooter range, for a given motor size. An average scooter will have a capacity of around 250 Wh and be able to travel about 10 miles at an average of 15 miles per hour. Extreme performance scooters can have a capacity reaching into the thousands of watt hours and ranges of up to 60 miles.

Battery Brands

Individual Li-ion cells in an e-scooter battery pack are made by just a handful of different internationally-known companies. The highest quality cells are made by LG, Samsung, Panasonic, and Sanyo. These types of cells tend to be found only in battery packs of higher-end scooters.

Most budget and commuter electric scooters have battery packs made from generic Chinese-manufactured cells, which vary greatly in quality.

The difference between scooters with branded cells and generic Chinese ones is a greater guarantee of quality control with established brands. If that is not within your budget, then make sure you are buying a scooter from a reputable manufacturer who is using quality parts and has good quality control (QC) measures in place.

 Some examples of companies that are likely to have good QC are Xiaomi and Segway.

Battery Management System

Though Li-ion 18650 cells have amazing benefits, they are less forgiving than other battery technologies and can explode if used improperly. It is for this reason that they are nearly always assembled into battery packs that have a battery management system.

The battery management system (BMS) is an electronic component that monitors the battery pack and controls charging and discharging. Li-ion batteries are designed to operate between about 2.5 to 4.0 V. Overcharging or completely discharging can shorten battery life or trigger dangerous thermal runaway conditions. The BMS should prevent overcharging. Many BMS also cut power before the battery is fully discharged in order to prolong life. Despite this, many riders still baby their batteries by never fully discharging them and also use special chargers to finely control charging speed and amount.       

More sophisticated battery management systems will also monitor the temperature of the pack and trigger a cutoff if overheating occurs.

C-rate

If you’re doing research on battery charging, you’re likely to encounter C-rate.  C-rate describes how quickly the battery is being fully charged or discharged.  For example, a C-rate of 1C means the battery is charged in one hour, 2C would mean fully charged in 0.5 hours, and 0.5C would mean fully charged in two hours. If you fully charged a 100 A·h battery using 100 A current, it would take a one hour and the C-rate would be 1C. 

Battery Life

A typical Li-ion battery will be able to handle 300 to 500 charge/discharge cycles before diminishing in capacity.  For an average electric scooter, this is 3000 to 10 000 miles! Keep in mind that “diminish in capacity” doesn’t mean “lose all capacity,” but means a noticeable drop of 10 to 20% that will continue to get worse.

Modern battery management systems help to prolong the life of the battery and you shouldn’t worry too much about babying it. 

However, if you’re keen on stretching the battery life as much as possible, there are some things you can do to exceed 500 cycles. These include:

  • Don’t store your scooter fully charged or with the charger plugged in for prolonged periods.
  • Don’t store the electric scooter fully discharged. Li-ion batteries degrade when they drop below 2.5 V. Most manufacturers recommend to store scooters with a 50% charged, and top them up to this level periodically for very long-term storage.
  • Don’t operate the scooter battery in temperatures below 32 F° or above 113 F°.
  • Charge your scooter  at a lower C-rate, meaning charge the battery at a lower rate relative to its maximum capacity to preserve/improve battery life. Charging at a C-rate between below 1 is optimal. Some of the fancier or high speed chargers let you control this.

Learn more about how to charge an electric scooter.

Summary

The main takeaway here is don’t abuse the battery and it will last the useful life of the scooter. We hear from all kinds of people about their broken electric scooters and it’s rarely a battery problem!

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Frequently Asked Questions

How long do electric scooter batteries last?

Electric scooter batteries will last between 2 to 4 years and between 3000 to 5000 miles depending on storage, use conditions, and battery capacity. If you use your scooter more or store it improperly, the battery life will be shorter.

How many times can you charge an electric scooter battery?

Electric scooters can go through between 300 to 500 charging cycles before starting to lose battery capacity. The highest-quality, brand name cells may last upwards of 1000 charging cycles, if babied.

How can you maximize electric scooter battery life?

You can prolong battery life by storing the scooter charged to 50%, charging it with a C-rate below 1, and not operating the scooter when it is too cold (below 32 F°) or too hot (above 114 F°).

When storing for prolonged periods of time, make sure to top the batteries periodically. When storing for very long periods of time, make sure to charge them periodically so they are not being stored completely discharged.

Learn more about how to maximizing battery life.

Can you replace electric scooter batteries? Is it worth the cost?

Yes! you can replace the battery in your electric scooter, though it may not be cost effective. Batteries are one of the most costly components of the electric scooter. Even a small 250 watt hour battery, like that from an M365, costs around $150 US or about ⅓ the cost of the entire scooter!

For common scooters like the M365, there are many video tutorials online of the replacement procedure. It’s not that difficult if you are mechanically inclined, but the novice may find it difficult.

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About the Author

Justin

Justin a cofounder of ESG and has a degree in engineering. He writes about the science and technology of electric scooters.

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