Charging and caring for your lithium-ion ebike battery

Your electric bicycle battery is quite expensive. Understanding how to charge and maintain it correctly can extend its lifespan by 2 to 3 times. There are also some things to avoid that can significantly shorten the battery's lifespan. This article will tell you:

 

What to do when your battery is new

Basic electric bicycle battery charging guide

How to store it when you're not riding for a while

Lithium-ion batteries and safety

How to prolong battery lifespan

Charging with a "smart charger"

These guidelines and instructions assume that you purchased the battery together with the motor or electric bicycle, and their power and charging capacities are matched accordingly.

If you purchased them separately, you will need to learn more information to ensure you have the correct battery and there are no potentially dangerous combinations. Ideally, the battery should provide more capacity than the motor requires, and the charging speed should be faster than the charger's charging speed. Both have room to spare, so your battery won't be stressed, making it safer and prolonging its lifespan.

 

Lithium-ion batteries require minimal maintenance. The battery's longest range is achieved when it is charged between 30% and 80% capacity. Unlike other chemistries, lithium-ion batteries do not have a memory effect and can be topped up as needed.

 

When your battery is new:

Before use, it is recommended to fully charge the battery. For the initial charge, you should charge the battery to 100%. If time permits, leave it on the charger for about 12 hours to ensure an even distribution of battery charge. Afterward, if you have a smart charger, you can charge it to 80% or 90% to extend battery lifespan. Then, every few months or so, perform a full 12-hour charge after a deep discharge to recalibrate the battery.

 

Basic electric bicycle battery charging guide:

 

The battery can be charged on or off the bicycle.

First, plug the charger into an AC power outlet. If there is a switch, turn it on and then off. This charges the internal capacitors of the charger and prevents a surge current to the battery.

Next, plug the charger into the charging port of the battery, and if there is a switch, turn it on. Most chargers have a set of LED lights. One of them will be red during charging and turn green when the battery is fully charged. When the indicator light turns green, the charger is not charging the battery and should be disconnected.

 

Ensure that the battery is not near flammable materials during charging.

For Electrify Bike Co batteries with switches, turn them on before charging.

Disconnect the charger when the green light is illuminated.

Charge the battery when the remaining capacity is between 30% and 60%.

Partial charging extends battery lifespan more than full charging.

Do not charge below freezing or above 50°C (120°F).

Perform a 100% charge every 1-3 months.

 

Storing Your Lithium-Ion Electric Bicycle Battery

 

When you are not riding your electric bicycle temporarily, there are two crucial things to consider when storing the battery: the charge percentage and the temperature. If you plan to store the battery for more than a few weeks, you should set its charge level between 40% and 70%. Do not store the battery at 100% charge as it will shorten its overall lifespan. Additionally, avoid storing the battery with a charge level below 40% as the capacity may degrade over time. If it falls below its low-voltage limit (around 2.6-2.8 volts per cell), it may become permanently damaged and might not be rechargeable thereafter.

 

During long-term storage, it is advisable to periodically check the voltage and recharge it to above 50% as needed. This frequency can range from every 3 to 6 months.

 

Keep the battery at a moderate temperature. Lithium-ion batteries that are partially charged tend to have a longer lifespan when stored in a cool place. The worst combination is high voltage (100%) and high temperature. For long-term storage (several months or longer), store the lithium-ion battery at approximately 50% charge. Ensure that you do not leave the battery in a place where the temperature may rise above 120 degrees Fahrenheit for an extended period, such as a closed vehicle or a building without climate control.

 

If the temperature drops below 32 degrees Fahrenheit (0°C), do not charge the battery, as it may be damaged. Place the battery indoors and allow it to warm up before charging. Discharging the battery (riding the bicycle) is possible in cold weather, but it will reduce your range. However, it will not harm your battery or shorten its lifespan. Conversely, if the temperature exceeds 120 degrees Fahrenheit, do not charge the battery, as it may also be damaged.

Lithium-Ion Batteries and Safety

Lithium-ion batteries can pose a fire hazard. This risk is significantly reduced if you purchase high-quality batteries from reputable sources that use branded cells. However, the risk increases if any cells within the battery are damaged due to drops or exceeding charging/discharging limits. Do not leave charging batteries unattended, and avoid charging them near flammable materials. If the battery is visibly damaged due to drops or water exposure, it should be recycled and replaced.

 

Failure to charge lithium-ion batteries in accordance with the following guidelines can shorten their lifespan and pose significant safety hazards.

 

Lithium-ion Battery Charging Temperature:

0°C to 45°C (32°F to 113°F)

 

Lithium-ion Battery Discharging Temperature:

–20°C to 60°C (–4°F to 140°F)

 

Extreme Temperature Guidelines:

Charge at reduced current below 41°F.

Charging below freezing is not permitted.

Good charging and discharging performance at higher temperatures but with a shorter lifespan.

 

Extending Battery Lifespan

 

Lithium-ion batteries, unlike some other technologies, do not have a memory effect, so you can charge them at any time without fully discharging them. When charged to 100%, it is expected to go through about 300-400 full charge cycles before the battery capacity drops to 80% of its original capacity. In terms of range, this means that if your new battery can travel 20 miles at 80% capacity, it will only travel 16 miles after 300-400 full charge cycles.

 

The simplest way to extend battery lifespan is to only charge it to 80% or 90% when you won't be riding for a few days. Most recreational rides don't require a full charge anyway. Doing so can extend the battery's lifespan by 2 to 4 times. Charging to 90% will give you around 1000 charge cycles, while charging to 80% will give you around 1600 charge cycles. This is similar to how you treat your smartphone. After charging it every day for a year, you'll notice that its talk or screen time is only 80% of what it used to be.

 

If you know you're going on a long ride and want to ensure the battery has enough charge, feel free to charge it to 100%. Doing so before a ride won't shorten the battery's lifespan. To control charging at 80% or 90%, you would need an "advanced" or "smart" charger that has this feature. Most chargers that come with electric bicycles do not have this capability.

 

If you use a smart charger to extend battery lifespan by charging to 80% or 90%, you should occasionally (every 2-4 months) balance the battery. To do this, you'll need to perform a deep discharge (below 30%) and then charge the battery to 100% to give the battery management system (BMS) a chance to rebalance the battery for maximum capacity.

 

Subjecting the battery to high drains will shorten its lifespan. If your battery is rated for a continuous power of 40 amps, it doesn't necessarily mean you should run it at that power for extended periods. If your battery feels hot to the touch during use, it may indicate that you're drawing too much current for too long. The BMS of the battery may allow you to draw more current when needed, but you should be aware that it should not be abused.

 

Avoid charging the battery too quickly or too frequently. Just like electric cars with fast-charging stations, you can also fast-charge electric bicycles. Electric car manufacturers warn against relying solely on fast-charging stations as it can shorten the lifespan of the car battery. Unlike fast chargers for cars, most electric bicycle fast chargers operate within the safe charging limits of the battery and do not shorten its lifespan, unless you have found and purchased an ultra-fast charger.

 

For example, all the batteries used by Electrify Bike Co. can be charged at 1.5 amps without decreasing the battery lifespan. Our popular battery, the Super Shark, consists of 14 series cells and 4 parallel cells. Four times 1.5 amps equals 6 amps, so the charger can charge at a current of 6 amps without reducing the battery lifespan. Our fastest chargers are only four and five amps, which is two-thirds of the safe charging level. Each battery also has a safe fast-charging rating, but frequent use may decrease the battery lifespan. This rating is approximately 2.5 amps per cell, so a 4P battery has a rated current of 10 amps. Even the Electrify Bike 2P Mini-Max battery can handle a 5-amp charge without reducing the battery lifespan. This is one of the many advantages of using high-quality batteries in battery manufacturing.

Using "smart chargers" for charging

Smart chargers can automatically stop charging when the battery reaches 80%, 90%, or 100% capacity. This can be selected using a rotary switch at the end of the charger. Electrify Bike Company offers smart chargers in 2-amp and 4-amp sizes, suitable for 36V, 48V, 52V, and 72V batteries. We also provide advanced smart chargers with the same voltages and an additional rotary switch to select 1 to 5 amps. The advanced smart chargers also feature a display screen with switches to show voltage and current.

 

The recommended way to use a smart charger is to charge to 90% after each ride, so your bike is always ready to go. Then, if you're planning an extended ride and want to ensure maximum battery range, you can charge it to 100%. Charging the battery to 100% before a ride will not have a negative impact on battery lifespan.