How to choose the type and capacity of lithium batteries

First of all, you must calculate the continuous current to be supplied by the battery based on your own motor power (requires actual power, and generally the riding speed corresponds to a corresponding actual power). For example, if the motor continues to have a current of 20a (1000w motor at 48v), the battery must be able to supply 20a current for a long time and the temperature rise is very low (even if the temperature is 35 degrees outside in summer, the battery temperature is best controlled below 50 degrees). In addition, if the current is 20a at 48v, the overpressure is doubled (96v, such as ecpu3) and the current continues to about 50a. If you like to use over-voltage for a long time, please choose a battery that can continue to supply 50a current (still pay attention to the temperature rise). The continuous current of the battery here is not the nominal battery discharge capacity of the merchant. The merchant claims that a few C (or hundreds of amperes) is the battery discharge capacity, but when the battery is discharged at this current, the battery heats up very seriously. If the heat is not properly dissipated, the battery life will be very short. (And the battery environment of our electric vehicles is that the batteries are stacked and discharged, basically leaving no gaps, and the packaging is very tight, let alone how to do a good job of forced air cooling). Our use environment is very bad. The battery discharge current needs to be derated for use. Evaluating the battery discharge current capability is to see how much the battery's corresponding temperature rise is at this current. The only principle discussed here is actually the temperature rise of the battery during use (high temperature is the deadly enemy of lithium battery life). It is best to control the battery temperature below 50 degrees. (Between 20-30 degrees is best). This also means that if it is a capacity type lithium battery (discharged below 0.5C), the continuous discharge current for supplying 20a needs a capacity of more than 40ah (of course, the most important thing depends on the internal resistance of the battery). If it is a power-type lithium battery, it is normal to continue to discharge according to 1C. Even A123 ultra-low internal resistance power type lithium battery, it is usually best to discharge at 1C (no more than 2C is better, 2C discharge can only be used for half an hour, which is not very useful). The choice of capacity depends on factors such as the size of the car storage space, personal expenditure budget, and the expected range of the car's activities. (Generally, small-capacity lithium battery must be powered) Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous: Analysis of maintenance methods for lithium battery protection board