E-bike battery overview: how to choose?
Updated: Dec 20, 2022
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The battery is an important component of the electric bike, providing autonomous power for the electric motor. The ebike battery type determines its weight, cyclic life and operating temperature range. The mileage of the electric bike on a single charge depends on the battery capacity, and its voltage affects the speed and must match the operating voltage of the motor and controller. Therefore, the battery for an electric bicycle must be selected taking into account the desired range and the characteristics of other electrical components.
Electric bikes are equipped with the following types of batteries:
lithium iron phosphate (also called Lifer)
lithium ion (Lithium)
lithium polymer (LiPo)
Beginners, as well as people who are pathologically short of money, or trying to save money, most often use AGM lead-acid batteries. Some cyclists go even further and make batteries from elements for uninterruptible power supplies, which are the cheapest. The main problem of these elements is that they are designed for surface currents, and in the mode of deep discharges - charges, they do not live very long. Factory AGM type ebike battery works better and last longer because they are designed for use as traction for electric vehicles. When buying, you only need to test the battery to make sure it works.
Now let's look at each type of battery in more detail.
Lead-acid e-bike batteries
Lead-acid batteries are cheaper than others, they are unpretentious in operation and are able to work in cold weather. These batteries are:
safe to use
heavier than others
therefore load the e-bike
impairing its handling and reducing the load capacity.
If we take batteries with a small capacity and weight, less than those recommended by the manufacturer, for a given type of wheel e-bike motor, then with a high discharge current, their capacity decreases. When driving your electric bike with a small battery, it is recommended:
not to accelerate hard
do not accelerate quickly
refrain from high speeds.
Discharging completely, the e-bike battery quickly loses its capacity and ability to recover. Therefore, installing low-power lead-acid batteries does not do anything good either in terms of maximum speed and mileage, or in terms of their durability. Save only on weight, but you will have to change batteries 2-3 times more often than normal capacity. Therefore, if you take "lead", then only the capacity that is recommended.
Rahul, GIN X e-bike co-founder, says that nowadays noone is using lead-acid e-bike batteries because they are outdated and heavier for electric bikes.
Lithium-polymer e-bike batteries
Lithium-polymer ebike battery is cheaper than others, has a high output current and are light in weight. Such batteries, by the way, are installed in all mobile electronics - from mobile phones to laptops. They serve reliably usually for 4-5 years. If you treat it with special care, then even more. The main disadvantage of these batteries is their poor fire resistance. In case of mechanical damage or overcharging, they may ignite. Therefore, to avoid the first risk, and to prevent the second, use a regular charger, which all normal companies sell complete with a battery. LiPo batteries also:
do not like frost, in the sense that they work, but their capacity is reduced
it is impossible to charge them in the cold
to improve safety, this type of battery, in case of self-assembly, is recommended to be protected with fireproof cloth, bags and case, and it is advisable to be always on the alert.
Battery cells do not require careful balancing like other types of batteries.
Lithium-ion e-bike batteries
Lithium-ion batteries are safer than LiPO, they are a little less afraid of frost, weigh more and cost more (price fork between LiPo and LiFePO4 batteries). The most common type of these batteries is lithium-manganese. Lithium ion batteries also include lithium iron phosphate batteries (LiFePO4), which are characterized by:
high power density
ability to operate in cold weather
large number of charge/discharge cycles.
True, it costs more and, in terms of the total amount of energy delivered for the entire time of operation, the energy received from lithium iron phosphate e-bike batteries will not be any cheaper than the energy from lithium polymer batteries.
Rahul, CEO of GIN X e-bike, mentions that lithium-ion e-bike batteries are very efficient and widely used battery across e-bikes. This is the main reason why while designing the GIN X electric bike, he preferred the Tesla grade lithium-ion battery with 48V for improved performance.
Check also our article about Fastest Electric Bike
Overview of e-bike batteries voltage
So, we know about e-bike battery types, we understand a little in terms, now it's time for me to tell you about the most important part - the battery voltage. There few type of e-bike battery voltage:
We sell batteries with a voltage of 48 volts. 36 and ebike battery 48v are 90% of the e-bike battery market. If desired, we can make a battery for 52v ebike battery, 60, 72 and higher volts, but this is possible on a separate request.
Most of the e-bikes you know are over 12V, and their voltage starts to rise from 24V, and they are very weak. Small 36V bikes, as you know, are the average standard in this evolution of e-bikes.
And completes this chain of ebike battery 48v systems, which, as a rule, are installed on high-power bikes. By the way, our GIN X e-bike has a 48V battery. Of course, there are craftsmen who put 60 and 72 and 96V electrical systems on the bike, but most electric bikes operate in the 36 and 48v ebike battery range.
This legacy remains from the days when acid batteries were used in everyday life, including on electric bicycles. And if you look inside the acid battery, they are made up of 2-volt cells that can be easily connected together in groups of 6 to make a 12-volt battery. And already based on this result, you can make 36 and 48v ebike battery. In general, this voltage has become common for electric bicycles.
The maximum speed of an electric bike depends on the voltage, for example, if the Bafang BPM motor is idle on a stand with a voltage of 36V, then the maximum speed will be about 37 km/h, and if at 48V, then about 45 km/h.