Adjust voltage drop using on board voltage step-up

[EliotBR (Eliot)]

Hi @hesham0120,

@hesham0120

My question is that I am not sure if this plan will work since I feel that some power calculations are not adding up and wanted to see opinions about this idea.

Your numbers seem to match those from our calculator, so if you have a 12V 20A supply, and you’re expecting 20A@8.9V to be sufficient as the input to your boost converter then it should be ok.

If you’re expecting your ROV load to be 20A@12V then you need to factor in the efficiency of the converter, which is not specified at the link you’ve provided (it just says “up to 95%”). Lower efficiency means you require more current as input to get the same power output, and higher current increases the voltage drop through the cable.

@hesham0120

The other more affordable solution I have is to transmit with 48V and step-down to 12V (much cheaper than using thicker wires). my math tells me this plan is more practical but since we already have the step-up module I wanted to see if I can use it instead of buying a 48v-12v one.

Higher tether voltage reduces tether inefficiencies, but may have additional conversion inefficiencies, so there’s a tradeoff involved. You’ll also want to consider things like

• cost (of the tether and converter(s))
• tether flexibility and drag
• safety (there are additional safety concerns as the voltage increases, especially if your vehicle is co-operating with humans submerged in salty water)