Understanding BMS
All the bikes we carry at Four Star have an internal BMS, or “battery management system.” This is a computer chip inside the battery that monitors the battery's health and status, identifies potential errors, and protects the cells from overheating. The BMS ensures sure the battery is charged and discharged properly, prevents overheating and overcharging, protects against reverse polarity when plugging in, and connects to the firmware system in our shop to communicate any errors.
The BMS can be reset and you may be instructed to do so by an e-bike professional if the battery is showing an error when charging. E-bike batteries are one of the most valuable components on your bike, and an intelligent BMS system (like the ones designed by Bosch and Shimano) are critical to ensuring your battery is safe and stable for years of riding.
Battery storage
The best place to store your bike and battery is inside in a cool, dry place protected from the elements. When storing outside, use a cover to protect your bike and keep a close watch on external temperatures. If you’re storing outdoors all the time, it’s a good idea to bring your battery inside overnight.
When using your e-bike and battery regularly (like commuting every day), you can store the battery with the bike as long as the temperatures do not fall below freezing. Once those cold temperatures arrive, batteries should be removed and brought indoors between rides.
If you plan to store your e-bike for several weeks or months without riding (like through the winter), there are a few additional steps needed. Remove your battery from the bike with a charge level of 30-60% for Bosch batteries and 70% for Shimano batteries. Store the battery indoors lying flat with plenty of space for ventilation around it.
Never charge a cold battery
It's important to store your battery at the proper temperature, and even more important to never charge the battery in a cold environment. This will significantly reduce the life of your battery, and could cause damage to the cells inside. During colder months, bring your charger indoors and allow your battery to warm to room temperature before plugging in to charge. Lithium-ion batteries can be damaged when stored in extreme temperatures or when exposed to direct sunlight for long periods of time.
Batteries charging at the shop. Area is well ventilated, near a smoke detector, climate controlled, and supervised.
Certification and charging
All of our bikes at Four Star have batteries with intelligent BMS systems and are certified by Underwriters Laboratories (UL), a third party that tests batteries for safety and stability. UL evaluates the manufacturing process of the battery, its chemical makeup, and performs tests for battery failure during charging and operation. You can have peace of mind knowing that your UL certified battery is among the most well-tested and safest batteries on the market today.
To charge your battery, first power off the battery using your e-bike display or the power button on the battery itself. Then plug in to the appropriate charger by the same manufacturer. Using off-brand or off-market chargers can cause serious damage to your battery and may void any warranty remaining.
Final tips
All batteries that come with Four Star’s e-bikes are from high-quality brands that boast the highest safety standards in the industry. With these tips, you know how to best care for your e-bike’s battery, allowing you to enjoy your bike for miles to come! Below is a final checklist of the most important ways to care for your e-Bike battery and links to manufacturer manuals and guides.
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Always power off your bike before plugging in the battery to charge
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Charge indoors, in a well-ventilated area, at room temperature
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Never charge a cold battery—allow it to warm to room-temperature before charging
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For long term storage, keep your battery at 30-60% of a full charge
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For storage between rides, keep your battery (and bike) out of direct sunlight, in an area protected from the elements, and at a temperature above 32°F
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Use a thermal cover for long rides in cold temperatures (below freezing)
Happy riding!
