Building 48V 500 Wh 18650 Battery Pack

[TheElectrician]

Hey Guys,

I am building a battery pack for the first time. I have designed the battery pack and I would like to know if I have done it in a right way. Any inputs on design changes or improvements is much appreciated. Please check attached picture.

Thank you

 

[izeman]

LiFePo4 is 3.2V nominal. Not 3.6V
48V nominal needs 15 cell in series. And around 10Ah. If you take 2.600mAh cells that's 4 in parallel.
You will build a 15s4p pack = 60 cells and total capacity will be 499.2Wh.

 

[izeman]

If you use LiIon cell voltage is 3.6V nominal. So you need between 13 or 14 cells in series.

 

[TheElectrician]

Hey, thanks for response, 13S4P sounds more simple. I was planning to connect 4S to make 4 12V battery. Then connect them in series to make a 48V. Do you think that will affect the design in anyway (Cost, Performance, etc.)?

Also, I already have a 48V Charge controller that converts AC to DC from the wind turbine that also charges the battery. I got this from china and that does not really have a charging current info. on the spec. sheet, so I was wondering how I should go about choosing the BMS for this.

 

[john61ct]

What is the use case? Is portability critical? What sort of C-rates?

EV or stationary? Inside a living space? Leaving unattended while charging?

 

[izeman]

Yeah. Use case does matter.
And power need? How many Watts/Ampere do you need.
And every connector adds resistance to the circuit which leads to a voltage drop. So the less connectors and the shorter and thicker the wires are the better the end result will be.
Maybe post a picture of how you plan to layout the battery.