I want to make a 9v power supply for audio equipment, please give me some advice

[crystal2080]

The working voltage of the guitar effector I use is 9v. I want to make a 9v mobile power supply. I plan to use 6 18650 batteries. I don't know how to connect in series and parallel. Will there be noise interference when using a switching circuit to boost the voltage? For advice, thank you very much!

[antonis]

Hi & Welcome..

Each single 18650 battery exhibits a voltage of 3.7V so for 9V you need X2.43 cells..!! (not an integral number..)

Batteries connected in series are capable for more voltage (V_total =  V1 + V2 + ... + Vn) where connected in parallel are capable for more current (I_total = I1 + I2 + ... +In)
More current means more capacity so 2 X 18650 (5000mAh) in parallel give 3.7V (single voltage) and 10Ah (double capacity) where in series give 7.4V (double voltage) and 5Ah (single capacity)..

[Vivek]

Consider using USB battery pack
Plus this

https://www.amazon.ae/Mission-Engineering-Power-529-Converter/dp/B07774ZV3N

That's more like "buy" than "make"

[bamslam69]

I considered making one, but instead I just bought this.

https://www.artistguitars.com.au/buy/joyo-jp05-rechargeable-isolated-power-supply-brick/15206

Cheap, quiet, awesome.

[vigilante397]

I'm a violently DIY person, I frequently build things when it would be cheaper and easier to buy it out of sheer stubbornness.

But my advice for this is buy something already out there, as mentioned above.

[Mark Hammer]

Some things we don't know:
1) The "effector" in question.  What is its current draw or indicated requirements?
2) Do you plan to share your battery supply with more than that one device?

[Steben]

Hi & Welcome..

Each single 18650 battery exhibits a voltage of 3.7V so for 9V you need X2.43 cells..!! (not an integral number..)

Batteries connected in series are capable for more voltage (V_total =  V1 + V2 + ... + Vn) where connected in parallel are capable for more current (I_total = I1 + I2 + ... +In)
More current means more capacity so 2 X 18650 (5000mAh) in parallel give 3.7V (single voltage) and 10Ah (double capacity) where in series give 7.4V (double voltage) and 5Ah (single capacity)..

(2 x (3 x series) parallel) will give 11.1V with double capacity
(3 x (2 x series) parallel) will give 7.4V with triple capacity

both options might work depending on what circuit is used. Most Opamp based circuit will work.

[antonis]

(2 x (3 x series) parallel) will give 11.1V with double capacity
(3 x (2 x series) parallel) will give 7.4V with triple capacity

So we can use 12 cells, place the above configurations in series with middle tap between outer (+) & (-) and get 2 X 9.25V..
Pas mal ..