The electric bike battery is a very technical subject. When choosing it, many questions are asked: voltage of 36 V or 48 V? Lithium, lead or nickel? How many Watts? Ampere-hour? Which brands are really reliable? Discover the easiest electric bike battery guide on the web.
What are the best electric bike batteries?
36V electric bike batteries
48V electric bike batteries
How to choose your EAB battery ?
Here are the (technical) questions to ask yourself when replacing the battery of your electric bike.
- Lithium, lead or nickel?
- Power in Watts and voltage
- Autonomy and efficiency
- What are the best brands of bicycle batteries
Lithium, lead or nickel battery?
It is important to know that there are several families of batteries for electric bikes. Each one has its own specificities in terms of lifespan (number of cycles), weight and performance. Follow the guide:
Lead acid batteries (400 cycles)
Lead-acid batteries are the cheapest and you will understand why. They have the advantage of being very little sensitive to the memory effect. You know, that phenomenon that affects the performance of some batteries if you recharge them before they are completely discharged. Lead-acid models, on the other hand, fear the cold, are bulkier and, above all, heavier.
Nickel batteries (500 cycles)
Among the nickel batteries, we find mainly those with nickel metal hydride (Ni-Mh). Contrary to popular belief, they do suffer from the memory effect and self-discharge. Lighter than lead-acid batteries, they also accumulate more power for an obviously higher price. Their limited lifespan tends to make them disappear in favor of their little sisters who run on lithium.
Lithium batteries (1200 cycles)
If lithium batteries now dominate the market, this is because of their efficiency. With 2 to 3 kg (4 – 6 lbs) on the scale, the lithium battery has a weight-performance ratio that is far superior to that of its lead-based counterpart. This technology is proven since it is also used in smartphones, laptops… and has the best lifespan (between 700 and 1200 charge/discharge cycles).
Another telling figure: the efficiency of a lithium battery can reach 90%. This means that during a charge, for every 100 Wh of electricity entering the battery, 90 are effectively stored. Among the types of lithium batteries, LiFePO4 (lithium iron phosphate) is slowly gaining ground. This is for three reasons:
- Its lifespan: we can exceed 3000 cycles of charge/discharge
- Its high safety : almost no risk of fire or explosion
- Its “green” side : lithium iron phosphate is not very toxic
The only drawback is that the energy density of a LiFePO4 battery is lower than that of a lithium-ion battery. For the same power, the weight of a LiFePO4 will be higher.
The future? It may be through sodium (Na), a resource less scarce than lithium. In Amiens, the startup Tiamat (which has just raised 3.6 million euros) has developed Na-ion cells optimized for 4,000 charge/discharge cycles and an ultra-fast recharge time of a few minutes. Successfully tested by the company on a scooter, the sodium battery could well equip our electric bicycles within 2 or 3 years.
Watts, Ah, Volts : Understanding the values indicated on the battery
Not all batteries store the same amount of energy. This quantity, expressed in Wh, is calculated simply by multiplying the voltage (generally 36V) by the battery capacity, expressed in Ah. The power, expressed in Watts, corresponds globally to the autonomy. Unless you are riding an unbridled bike, it is not the same. should not exceed 250W. If your bike is unbridled, then you can aim for batteries between 400 Wh and 500 Wh. To summarize, remember that :
- The more Wh your electric bike battery has, the longer it will last. A 500Wh battery will last twice as long as a 250Wh battery.
- The higher the value in Ah (Ampere hours), the more autonomy you will have.
- You must choose a model with the same voltage as your old battery (usually between 24V, 36V or 48V)
What are the best electric bike battery brands?
It’s not easy to find your way through the vast choice, which is made up of everything and nothing. Don’t be blinded by an abnormally low price: quality cells, you have to pay for it. We would not encourage you to buy a low-end model, but rather to trust reputable battery brands: Bosch and its famous Powerpack, LG, Bafang, X-Go, Green Cell Pro, CYCBT, HalloMotor, Panasonic, Yamaha, etc.
Where to install it?
You won’t go faster by placing the battery on the frame rather than on the rack, or vice versa. However, the behavior of the bike, and therefore your own riding sensation, may be affected. You should therefore avoid placing the battery on the luggage rack if you want to keep a sporty use of your bikeor if you have a motor on the rear wheel (question of balance). The same goes for the rear of the seat tube, not recommended if you want to preserve optimal maneuverability.
There are batteries with studied geometries that adapt to different frames. The best location is the one that stiffens the frame without damaging it, that does not unbalance the bike but preserves its agility, and that does not expose the battery to everyday shocks. Also be aware of the constraints of the bike itself: for example, a full-suspension bike will not necessarily allow you to place the battery at the bottle cage.
Is the operation easy?
Replacing your battery with an equivalent model is… VERY easy. However, if you choose an oversized battery or a different technology (e.g., switching from NiMh to lithium), it may require some skill and patience. Installing a new bracket, preparing new wiring, even soldering wires to terminals is indeed more of a do-it-yourself job than routine maintenance. Finally, make sure your charger is compatible with the new battery.
How do I preserve my battery life?
Here are a few simple things you can do to save your battery and extend its life:
- Store it at room temperature, between 10 and 25 degrees. Cold is an enemy of batteries! It reduces the voltage and disturbs the chemical reactions at the origin of the energy production;
- Remove it from the bike because the card imperceptibly but surely “draws” energy;
- Do not store it completely discharged (ideally between 40% and 60% of its charge) ;
- Lightly charge it at least once every 2 months ;
- Use it regularly ! This is still the easiest way to keep her on track.
However, two identical batteries stored in similar conditions will not necessarily provide the same performance. Indeed, the performance of a battery is also linked to parameters related to the rider, his races and the bike itself, for example :
- Rider’s weight;
- His pedaling frequency;
- The course profile (number and steepness of hills, wind strength, type of surface…) ;
- Number of stops and restarts;
- Tire pressure;
- Presence of a device connected in USB on the battery…
Can you recharge the battery of your electric bike while riding?
Unfortunately, no. At least not yet. Don’t expect to regain a few percent of autonomy on the downhill, by decelerating or why not by pedaling backwards. However, it may only be a matter of years before we see such an invention on our bikes.
Some manufacturers are working on the issue, like ThirtyOne or Sanyo. But for now, the gain in autonomy is too small. The BionX system does allow energy recovery, but you have to manually select the regenerative mode and, again, the gain in terms of recharging is meager.
Nevertheless, where there is a market, there is innovation, and let’s hope that the research and development departments of specialized companies will be able to produce an effective model in the short term! In the meantime, there is no choice: it must be recharged on 220V.
Tip: Choose a battery with a long life
Here’s a tip! If you buy a battery for your electric bike in a store, check its date of manufacture. A battery that has been stored for 2 or 3 years in a warehouse or at the back of a shelf will have lost its capacity. Even on sale, it is not worth the “cost”. You will have to change it prematurely.
Another important element to preserve your battery: a good “casing”, the case that envelops the whole. Especially if you plan to install it on an electrically assisted mountain bike for somewhat wild use! The casing must ensure a tight and effective protection against dust. The presence of the IP54 index (IEC 60529 standard) will reassure you, as it ensures protection against dust (number 5 of the standard) and water projections from all directions (number 4).
Finally, to estimate the life of a battery, we reason in terms of number of charge and discharge cycles. It is best to go for the models with the highest value. However, this number is only a guide. It depends on the storage and use of the battery.
What is a battery made of?
- Cells assembled between them, that is to say accumulators which store the energy
- A case, usually a sealed resinous assembly that protects the battery from shocks
- The wiring
- A mother board, or battery management systemwhich will manage and regulate the assistance in an intelligent way
What about recycling?
Batteries of electric bikes are generally guaranteed between 6 months and 2 years. After this period, once it has reached the end of its life, a question arises: where to dispose of this cumbersome waste?
Spoiler alert: not in the recycle bin. And even less in the neighbor’s composter, neither seen nor known #THUGLIFE !!! But you can actually get rid of it very easily, either :
- Simply at the waste disposal center, where there are bins for this purpose.
- At an electric bicycle dealer. It is an obligation for them to take care of the collection of used batteries.
- From a company specialized in reconditioning. The tired cells are replaced and your battery goes back for a ride, or rather a few thousand rides.
- Finally, some specialists offer to… buy your old battery back!
There is no shortage of collection points and recycling is becoming more and more efficient. It is estimated that 90% of the cells in a lead-acid battery can be reused. As for lithium batteries, although they have a longer life, there are no reliable figures for their recycling. The process is complicated by the presence of metals such as cobalt, manganese and nickel.
One thing is certain: research is progressing, and with it the ability to reuse used batteries. This is a necessity, especially in view of Tesla’s ambitions. The electric car manufacturer has built no less than 3 Gigafactories to supply batteries for half a million vehicles per year… Come on, let’s dream, with all these advances, soon a 100% recyclable battery?