Lithium-Ion is the best type of battery for an electric bike. They offer the best mix of value and performance.
Lithium-Ion: the best type of battery for cyclists
You are most likely to receive a Lithium-Ion (Li-Ion) battery if you buy your bike in Europe, the US, Australia, New Zealand or Japan.
Different types of Li-Ion battery are available for electric bicycles and each has both pros and cons. For more detailed information see the related question: What type of Li-Ion battery is best for an electric bicycle?
The Chinese continue to use Lead Acid batteries extensively and low-cost bikes (and bike conversion kits) may still include Lead Acid batteries.
Lead Acid batteries are heavier and have a lower capacity than Li-Ion batteries. They are also the cheapest form of battery available for electric bikes.
Advantages of Li-Ion batteries over Lead Acid Batteries
- Weight: Li-Ion batteries are one-third the weight of lead-acid batteries.
- Efficiency: Li-Ion batteries are nearly 100% efficient in both charge and discharge.
- Discharge: You can discharge 100% of a Li-Ion battery versus less than 80% for lead acid.
- Cycle Life: Rechargeable Li-Ion batteries cycle 5000 times or more compared to just 400-500 cycles in lead acid.
- Voltage: Li-Ion batteries maintain their voltage throughout the entire discharge cycle. Lead-acid voltage drops throughout the discharge cycle.
- Cost: Despite the higher upfront cost of Li-Ion batteries, due to the longer lifespan the true cost of ownership is significantly lower.
eBike Batteries to avoid:
- Nickel Metal Hydride (or NiMH) was once the main type of eBike battery and they can still be found in a small number of bicycles. They are unable to provide the power boost of Li-Ion and suffer some ‘memory’ problems.
- Avoid Lead-acid batteries unless up-front cost is your number one priority. They have a shorter lifespan, hold less energy and will end up costing you more in the long run. Note: cheaper electric bicycles may come with lead-acid batteries – if the bicycle specifications don’t indicate Li-Ion check with the manufacturer or re-seller.
- Nickel Cadmium (or NiCad) will not provide the high energy boost eBikes sometimes require as their ability to discharge quickly is poor. ‘Battery memory’ means they should be fully charged and fully discharged every time which is unrealistic for an electric bicycle. FInally, they are particularly toxic at the end of their lifecycle and difficult to dispose of.