Background
I'm trying to build a small hobby grade ROV for an underwater robotics competition held at the university I'm studying. And I have used eight brushed dc motors each of which consumes 8A on full load.
The whole system might consume about 75-80A at maximum usage. But we are pretty sure that we are not running all motors at the same time at full load and hence average current usage would be around 50-65A.
I have included eight 12V 8Ah SLA batteries inside our ROV and hope it might run for like one and a half hour at most on average.
Problem
One of the issues I'm having right now is with designing a PCB layout where wires from eight batteries are merged onto the PCB Board.
Please note that I'm not an electronics/electrical engineering student that I do not have proper and solid knowledge on power circuits and calculating thermal dissipation.
I just don't want to be a dumbass letting the PCB burns into smoke and flame from overheating. I am afraid that might happen when the amount of current stated above have to be passed through the plate.
I have space limitation and maximum dimension of the PCB for the distribution panel should not exceed 6"x6" dimension.
Above is the overview of the power supply and distribution concept for the ROV. After the summation of total current usage and wattage, to a shocking moment, it's around 1kW and 80A of DC 12V. Is it such a high usage of power in sense of power circuits? I never had an experience with circuits that use over 12V 35A. I'm afraid that I might be wasting a lot of power. But my ROV is a bit big in size, about 3'x2'x1.5' dimension of steel structure. But I'm pretty sure we are going to operate only four motors at the same instance and at 70% of full load at max. So I guess 50A is maximum for normal operation conditions.
My Questions
- How should I design my PCB for power distribution purpose only?
- Shall I use a typical thick PCB or a copper block with heat sink?
- Is the total overall power usage huge and not suitable?
- Your advice on making things better.