The first thing to consider is that the voltage of the Lifepo4 Battery you need. The maximum speed of your bike depends on the battery voltage, the higher the voltage, the faster the motor. If you want the engine to help you while continuously pedal your bike, you will probably need 36 to 48 volt battery. On the other hand, if you want to use bicycles more like bike and cruise around at high speed without pedaling anything from 72 to 100 volt rating will provide a much better performance. You should also make sure that the motor and controller is designed to battery you are using.

The next thing to consider is the battery capacity is how long the battery will last between charges. It is measured by the number of ampere-hours (Ah), it can run before it is empty. If the battery can run one continuously for one hour, it has a capacity of 1 Ah. The more Ah of battery capacity, greater physical size will be, if you compare the same chemistry. 10ah 5Ah battery will double the batteries if they are of the same type and have the opportunity to get your bike twice as far when traveling at the same speed. Some batteries can be connected in parallel (all positive terminals are connected together and all the negative terminals are connected together) to increase capacity or Ah to the desired level.

The last thing you need to consider the 'C' rating or degree of battery discharge. No rating 'C' battery, which is a continuous safe discharge rate (amps) cells. The battery is designed to 1C, to carry out its assessment Ah current without damage. 2C rated 18650 rechargeable battery can pay twice as much of their Ah rating in amps. 10Ah battery is designed to 1C, the maximum safe discharge rate 10 A, if 10Ah battery has a rating of 3C, can safely carry 30 amps. Similarly, if 10Ah battery at.5C can earn 5 amps safely.