Mobile device power solutions (Li-Ion in parallel)?

Question

Batteries

Good afternoon.
I have never dealt with the power of mobile devices before, but the need forced me. It is necessary to provide the following:
1) Output voltage 5V, current - up to 1A
2) Stored energy not less than 8Ah * 5V - that is, not less than 40 W * h.
3) Charging from USB
4) Minimum number of components / minimum area occupied on the board.
The fact is that these parameters are easily achievable when using several battery cells (together with a buck converter), but I have not seen a highly integrated balancing scheme anywhere.
Therefore, I want to take three to four separate cells of this type:

Connect them in parallel, after equalizing the voltage, and then use them as one battery with a voltage of 3.7 and a triple (quadruple) capacity, charging it, respectively, with one specialized microcircuit, which, for single-cell ones, is quite a lot.
Thus, the need for balancing disappears, it remains only to put a boost converter up to 5V at the output.
Gentlemen of electronics, does such a decision have the right to life? Judging by googling, often three-cell batteries are disassembled and reassembled in parallel instead of in series ...

Answer 1

Can. But it is desirable to put batteries with the same capacity in parallel. And a temperature sensor is very desirable, which will break the circuit when the temperature is exceeded. Such sensors are in standard protection boards.
We put such a board on each battery, and parallel. At the same time, the protection board will save you from full discharge and overcharging.

Answer 2

I myself am assembling an assembly for 4pcs [email protected] in parallel, I used just such a thing.

Answer 3

It is possible, even I will advise just such a thing.

You can put a battery like in your question or 18650 Li-ion
. By the way, it is for these batteries that the above box is intended.
In parallel - in principle, this is how it is done in a laptop battery. But there are thermostats. Install a thermal fuse
in series with each battery , 80 degrees.

Answer 4

They are assembled in parallel and in series.
Only by capacitance and resistance they should be tested and sorted
. Well, it’s even easier to power and charge everything through the controller, it can still monitor the temperature. What is very useful with liposhki