I'm working on project that is Powered with 8 LiIon batteries/cells connected in parallel. Everything Works fine until batteries run out of "juice". For charging module I decided to use TP4056(@ 1A). Now, problem is - TP4056 module can charge only one LiIon cell at the time, so I need 8 modules for proper charging(one module per cell). There is two versions of TP4056 module, one with over discharge Protection(pins: B+, B-, OUT+, OUT-), one without Protection(pins: OUT+, OUT-), so I decided to go with module that has over discharge Protection(now I'm asking myself why I did that). Next is scheme(I don't have it but I'll write it):
- Pins OUT+ and OUT- are connected in parallel(between modules). Those pins are in use as VCC for project(let's say it's "power source").
- One cell is connected on B+ and B- pins of one module. With that way one module charges only one cell(as it should).
But! Yesterday I found that sometimes(since I buy from eBay) those Protection modules have problem/bug and they aren't reliable. Also later I found that cut-off voltage is 2.5V, while manufactuer recommends 3V(in most LiIon cells). I guess this design will fail so I decided to find another solution.
So my question is: How to make this same "design" with TP4056 without over discharge Protection(only OUT+ and OUT- pins)? How I should connect batteries with modules so only one module charges one cell? Any advices?
I paid more than €50 for those 8 cells and last thing I want to do is to destroy them with wrong charging "design".
I'm not sure is my solution correct so I wrote this question. My solution is:
- Connect cell's positive pole to OUT+ pin of TP4056 and same thing with negativ pole(to OUT-).
- Connect cells in parallel and that use as power souce.
So my thinking is: While charging, current will flow where is less resistance(as river in nature), it will flow from OUT+ through cell then from negative pole to OUT-. Is that correct? But if cells are used as power souce then current will flow as normal in parallel connection. Am I right?
Thanks a lot!