Battery-based electric bicycles have become increasingly visible on our streets. These are assisted pedaling bicycles that give us a functionality similar to traditional bicycles, but with the advantage that they will not mean that we have to make the effort involved in pedaling. They incorporate an electric motor whose energy is provided by the batteries.
With advances in controllers and batteries, electric bicycles have made their way into a very efficient type of mobility for our interests, especially for those who saw the conventional bicycle with the need to add new functionalities that make it an even better solution. Thus, basically, they are bicycles to which an electric motor has been coupled . This motor can be integrated into the rear wheel, front wheel or near the bottom bracket. The motor helps the bicycle to move forward and receives energy from the battery that is recharged from the electrical network.
What batteries do electric bicycles use?
In this sense, and as is the case with new generation cars, batteries form a fundamental aspect in these electric bicycles. Above all because, as we mentioned, they are the ones that provide the energy to the engine that is attached to the wheels or the bearing. In this sense, its operation would not be the same without these storage units.
They, for their part, raise several doubts. The frequent ones are those that have to do with their functionality, useful life, autonomy they provide … and their advantages. Broadly speaking, those in charge of storing energy are usually lead or lithium . Normally, these would provide autonomies of up to 30 km, although it is possible that it is generally increased.
Added to it is the accumulator , which is usually located on the rear rack or in the middle of the bike, under the seat. At the same time, the electric motor is of the in-wheel type. Typically, the motor is located on the rear wheel, although there are designs that carry it on the front wheel. This will cause the bike to also have all-wheel drive.
What are the existing types
Because if. We could say that a motor without batteries is nothing. From there, they attack characteristics such as its power, which is measured in watts / hour (Wh), an energy measure to know its capacity. When it comes to having one or the other that are better, the batteries of these Mobility Vehicles will do because we select between three generations with which we will also obtain a higher voltage and amperes for energy. In this case, these variants currently exist.
- 1st generation or Gel-Lead batteries and AGM-Lead batteries.
- 2nd generation or Nickel Metal Hydride (Ni-MH) batteries and Nickel Cadmium (NiCd) batteries.
- 3rd generation or lithium batteries .
As for the former, these are the ones that were incorporated in the early days where it was done because bicycles could also be powered by a battery-powered electric motor. Regarding these, it should be noted that, despite being the oldest, they are one of the most used. They are lead batteries in two variants: AGM-Lead and Gel-Lead. They are designed to withstand deep loading and unloading cycles. Its capacity is 25Wh per Kg.
In turn, the second generation ones soon arrived, here with those of Nickel Metal Hydride and Nickel Cadmium. They were seen as a very practical solution because they are durable and considerably safer. In fact, they respond markedly better to third-generation lithium-ion batteries, in part because they don’t use flammable liquids. They achieve a capacity of 55-70 Wh per Kg.
Finally, we have the lithium-ion ones, the most innovative. Multiple advantages stand out, such as the lower energy density per cubic centimeter, a greater number of recharging cycles and, in addition, lighter: its weight in four times less than those of lead. They are also more durable. Its capacity is 90-190 Wh per Kg , which considerably favors the autonomy of bicycles.
How can we take care of them
Regardless of the battery manufacturer’s indications that you may have chosen, there are methods that will make them have a more or less durable life , depending on their materials or use. For this, and in order to guarantee correct use, some guidelines for battery maintenance are in phase.
These may be the most common, as it will always be appropriate to use the charger provided by the manufacturer for that battery, since they are precisely adapted for that model. At the same time, aspects such as degradation must be taken into account, which, in most cases, have a guaranteed use for two years. But later they will decline. give them proper use.
In addition, and if indicated by the manufacturer, the full charge and discharge periods must be performed periodically. Ideally, use the electric bike battery as a complement to pedaling, not use as a reduced speed motorcycle.
Power indicators
When it comes to determining what power these units will give to our vehicle, they are governed by several characteristics that make it of a higher or lower range. This is determined by the hand of which are the volts (V), amps / hours (Ah) and watts / hours (Wh). Thus, in this case, all three are very distinctive peculiarities.
- The Volt is the battery power. We can find versions of 24, 36, 48 and 72v . The higher the voltage, the higher the power. Most electric bicycles use 36V batteries, as it offers a good cost / effectiveness ratio. On the other hand, 72V batteries are much more expensive, and their high power could turn our electric bicycle into a moped, exceeding the legal limit on motor speed (25 km / h).
- Amps / hour . It is the one that will indicate autonomy. The higher the amperage, the greater the autonomy. In the case of electric bicycles it is very relative because it depends on the level of pedaling assistance we use. This can be derived from the weight of the bicycle, our own weight, the pressure of the tires, our way of driving … the most common is 10Ah .
- Watts / hour . Compare batteries of different voltages and amperages when deciding on one. A 24 volt 20AH battery will perform the same 480 watt hours as a 48 volt 10AH battery. It will behave the same.
Ability
The next characteristic that we should pay attention to is the capacity of these batteries for electric bicycles. To do this, and in order to determine its capacity, we can take the watts / hour as a reference , which is what will make a comparison between the different voltages and amperages.
Here, it will be done by multiplying volts and amps , as we have recognized in the power indicators. This can be, for example, a 24V 8Ah battery is 192 watt / hour in size, while a 36V 10 Ah battery would have twice the capacity: 360 watt / hour.
Useful life
After the capacity, a very interesting aspect of these will be their useful life. In the same way as in cars, it is measured in cycles . One cycle is the time between full discharge and post-charge. In standard models, the battery life of an electric bicycle is around 600 cycles, and there are some brands that can go up to 1000 cycles.
As cycles wear down, the battery’s ability to store energy is reduced by up to 70-80% compared to a new battery.
Autonomy
Autonomy plays another trick more than suggestive between some batteries and others. And it is that, depending on whether its autonomy is wider or not, we will be able to have a longer route. Thus, in general, the more watts per hour the battery has, the more autonomy it will offer. The number of refills indicated by the manufacturer is an indicator, but we also have to consider that it is not the only valid indicator since time is a relevant factor as well.
On average, an electric bike battery has a useful life of between 2 and 4 years depending on how we use it. From that moment on, they will begin to lose autonomy. This does not mean that we should change it immediately, but that the charging cycles will be shorter and they will lose energy storage capacity. As such, this one is very relative – it can go anywhere from 15-30 kilometers on touring bikes to 100 kilometers on high-end electric bikes.
However, it will not be entirely continuous forever. As shown by the amperes / hour, it will not be given only by its capacity but also by other external factors: weight, physical condition of the cyclist, the terrain … In this case, of course, a battery will not last the same with a person of 70 kilos than with a 100. Thus, an electric touring bike hardly exceeds 24 volts and therefore 250wh, while a mid-high range electric mountain bike can easily reach 350-400 Wh.
