What are our Batteries?
The battery cells we use on all ours bikes are SAMSUNG® manufactured cells. The chemistry is Lithium Nickel Manganese Cobalt Oxide (LiNiMnCoO2)
What is VOLTAGE and which Voltage is best?
Voltage can be thought of as the pressure or strength of electric power. All things being equal (see AMPS below), the higher the voltage the better, because high voltages pass more efficiently through wires and motors. Very high voltages (100+ volts) can give you a nasty shock because they also travel through people rather well, but the sort of voltages found on electric bicycles (12 – 36 volts) are quite safe. As a rule, a 12 volt system is fine for low-powered motors, but more powerful machines work better with 36 volts.
What are AMPS?
Amps can be thought of as the volume or quantity of electric power. To aid this analogy, the flow of amps is called the current, as in the flow of a river. Unlike a river, though, the speed of the current is fixed – only the volume varies.
The maximum flow of amps in a bicycle drive system can vary from 10 to 60 or more. A current of 60 amps requires thick wiring and quite substantial switchgear.
What are WATTS?
Once we know the voltage (or pressure) and current (or volume), we can calculate the power, or wattage by multiplying the two figures together. The number of watts in a system is the most important figure of all, because it defines the power output.
How many watts do I need?
As a general rule, a cyclist can produce several hundred watts briefly, and one hundred watts for a reasonable length of time. To be really useful, a motor needs to produce another 100 Watts on a continuous basis, with peak power of at least 400 watts. Just to confuse things, our measurements are of power consumption – losses in the motor and drive system mean that the power output to the wheel can be much lower.
If you expect the motor to do most of the work, especially in a hilly area, you’ll want a peak consumption of 600 watts or more. On the other hand, if you prefer gentle assistance, a peak of 200 watts may be enough.
Electric Bike Battery FAQ –
How big a battery do I need?
The capacity of the battery is usually measured as the amount of current it can supply over time (defined as amp/hours). However, this is useless on its own, because you’ll need to know the voltage too. By multiplying the two figures together, we get watt/hours – a measure of the energy content of the battery. Unfortunately, it isn’t that simple… but you didn’t think it would be, did you? In practice, you’re unlikely to get results that match the stated capacity of a battery, because battery capacity varies according to the temperature, battery condition, and the rate that current is taken from it.
Sealed Lead Aacid (SLA) batteries are tested at the ’20-Hour’ rate. This is the number of amps that can be continuously drawn from the battery over a period of 20 hours. However, an electric bicycle will usually exhaust its battery in an hour or two, and at this higher load, the battery will be much less efficient. So the figures for lead/acid batteries tend to look overly optimistic.
It’s best to choose a package that will provide twice your normal daily mileage. It’s difficult to guess the mileage from the watt/hour capacity, because actual performance depends on the bicycle and motor efficiency, battery type, road conditions, and your weight and level of fitness.
What types of Battery are there?
Nickel-cadmium (NiCAD)- mature but has moderate energy density. Nickel-cadmium is used where long life, high discharge rate and extended temperature range is important. Main applications are two-way radios, biomedical equipment and power tools. Nickel-cadmium contains toxic metals.
Nickel-metal-hydride (NiMH) – has a higher energy density compared to nickel-cadmium at the expense of reduced cycle life. There are no toxic metals. Applications include mobile phones and laptop computers. NiMH is viewed as steppingstone to lithium-based systems.
Sealed Lead Acid (SLA) invented in 1859 are the oldest type of recharge battery and are most economical for larger power applications where weight is of little concern. Lead-acid is the preferred choice for hospital equipment, wheelchairs, emergency lighting and UPS systems. Lead acid is inexpensive. Very short life in ebike applications since they were not designed for high discharge. NOT environmentally friendly – highly toxic.
Lithium-ion manganese (LiMh) – the saferst and fastest growing battery system for electric vehicle applications; offers high-energy density and low weight. Protection circuits needed to limit voltage and current. Applications include notebook computers, cell phones, cars and ebikes. High current versions are available for power tools and medical devices. Easy to recycle and reuse. Be careful with other types of lithium as some types are untested and have the potential for fires.
36 volt vs. 24 volt
36 volt systems boast faster speeds, quicker acceleration, greater range and better hill climbing capability than 24 volt systems. 24 volt systems are typically used on slower models that require pedal assistance to operate.
36 volt 10 amp vs. 36 volt 15 amp
The 36 Volt 15 Ah battery extends the range by 50%. For example, if a 36/10 gives 30 miles / 48km, a 36/15 will provide 45 miles / 72km. It’s a great option on both the City Commuter as well as the Comfort Cruisers for folks who desire range.
36 volt vs. 48 volt
The 48 Volt 10 Ah battery provides greater power and acceleration so if you are looking for extra kick and hill climbing capabilities order the 48 volt system.