This my third question about a 3S Li-ion charger circuit.
In the first one, I learned about the functions of a BMS: BMS adjusting charge current
In the second one, I learned that a charger circuit is needed to limit the charging current: 3S 18650 battery charge current limiter
I couldn't find a low cost 3S charger IC system.
I came across some examples using three TP4056 ICs on the internet. It has 2 limits:
- When I connected three TP4056s in series, I saw that there is not an equal 5 V drop across each.
- It also needs 15 V; I need to use a 12 V adapter.
I decided to use a step-down converter to supply 5 V to every TP4056 and also isolate their negative terminals using DC-DC converters.
Like this one.
Or with my drawing:
Is this diagram logical and suitable for my purpose? Are there things I missed? Specifically using DC/DC converters for isolating.
I need validation and criticism.
Probably I need to use a TP4056 model with integrated BMS: