Hello everyone
I want to design and then build a battery pack/power bank that can deliver 12V @ 3A. I will be using new 18650 cells. I want to use (as far as possible) modules I can buy from AliExpress.
My thinking was as follows:
- 4s2p pack
- 4s BMS (maybe 1 for each series strip?)
- 4s balance board (maybe 1 for each series strip?)
- Use a laptop charger to charge the pack or any other DC power source that can supply enough volt/current
- Step down DC to DC converter to go from charger/PSU to the 16.8V for charging the 18650s
- Another step-down DC to DC converter to give the desired 12V output
- Some visual indication to show the state of charge of the pack
After reading up on some BMS modules, and looking at several listing on AliExpress, I saw most specify an input voltage of 16.8V but still from specifically a lithium-ion charger. Some BMS modules claim to do balancing and others, although the same picture, claim not to be able to do balancing.
So now I am confused on what to get. :s I want a BMS/charge module with a balance function as well. Or, alternatively, separate modules that I can combine to perform the desired function.
Any advice?