You can electrodeposit onto two substrates at the same by connecting both the substrates in series in the same beaker. It is similar to increasing the surface area of your substrate. If you are electrodepositing under potentiostatic control, then you do not have to do anything on the current, because your power supply will take care of the current to maintain a constant potential. If you are electrodepositing under galvanostatic condition, then you have to increase the current to maintain the required current density. In any case, you have to increase the area of the anode to have a uniform electric field between the two electrodes.

When you have one power source connected to two beakers, then you have to have two anodes and two cathodes - resulting in two parallel circuits or loops. The voltage remains constant in both circuits, but the current is split. Your power source needs to be capable of supplying the required current. You do not know the exact current values flowing through each circuit, and therefore you need to have an ammeter connected to each circuit. The power source reads the total current.

Which one is recommended? It depends on the power source, contact potentials, and your solution chemistry. I would prefer a potentiostat to a DC power source because you can have a better handle on the I-V parameters and do not have to worry about the anode area.

If the rated power of your DC source is P and in the cell you apply a voltage U and a current I, then theoretically you may increase the number n of cells to maximum n = P/(UxI).

The best control parameter is current density: try to maintain it . Also pay attention to maintain the same flow rate or stirring in all cells.

For practical reasons I suggest you to maintain the actual cell configuration and to connect many cells in series (recommended) , in parallel or in a combination series+parallel.

The proposal "in the same beaker" is better defined as "increasing the surface area of your substrate" (same increase for anode), in fact as one cell, than a "series connection" ( that will not work in the same beaker).

Yes we do it a lot using a parallel set up -

https://www.zimmerpeacocktech.com/products/accessories/parallel-sensor-adaptor/

Hello,

Why do you think that serie wiring is recommended ? What is the difference with two channels (current sources) in the same bath ?

Thanks in advance,