Power supplies were what originally got us started in the ROV business. That was all the way back in 2018. We have come a long way from that first 500W supply, but I think it’s worth remembering where we started.
We learned a lot and have incorporated those lessons into our new products. We always continue learning. Our 3rd generation of power supplies for Blue ROV and similar systems are available now, such as our VPU 1k AC. Datasheets and pricing are available on our website: POSEIDON ROBOTICS, LLC - Lanai ROV, Deep Water Rovs, Rov
Here is one of our latest power supplies, a 6,000W system for our new Maui Gen2 ROV. At this scale, the standard 1oz copper on most PCBs could actually cause the board to catch fire. 4oz or thicker copper, integral cooling layers, thicker insulating layers, and careful housing and heat sink design are all required.
Have you ever considered developing a topside power supply similar to Deep Trekker, which provides a DC current down the tether to charge the battery onboard the ROV?
I suspect that providing, say, 500 watts of constant charging current down the tether could extend dive times by 2-3x, and could be done at a fraction of the cost of a full on surface power solution. I’m curious why I haven’t seen a similar product on the market yet?
Hello and thank you for the suggestion. Great minds think alike and we have already investigated this and are working on some related products.
The challenge is this: 24VDC to 48VDC (maybe pushing it up to just under 75VDC) is about limit of what can be done safely without all the expensive (and critical) added line isolation monitors and interlocks. At those voltages, the Fathom Tether would wouldn’t give much power. A quick calculation on a 150m tether suggest about 30W of charging power if using 4 wires of the tether. we have already prototyped a design based on this and have been testing it. There will be a board available soon.
Now 30W (to over 50W if we push a few things) is not half bad because the standard Blue Robotics battery only has 266Watt-Hours (266Watts for one hour). I find most Blue ROV2 (and Heavy) dives we’ve done last about 2 hours, with 1 hour being very hard flying in the open ocean and 4 hours being gentle cruising in a lake or pool. If we assume we can use about 80% of that 266Whr, then we have are only burning between 50W and 212W (average) per hour, with about 100W per hour being an average dive. While you might pull 1,000W for a few seconds, the average is much lower.
Flying the ROV at 500W continuous output means the battery would last only about 20min. 500W requires going well above 100V and adding both a new tether, a topside with safety equipment like isolated supply and GFCI/Line Iso. Monitoring, and a subsea housing with a heatsink. Thus, you already have the full system.
Thank you for the info. I never did the math on BlueROV power consumption. You’re right, if the average consumption is 50-200W, then 30-50W charging down the cable would significantly increase the dive time.
In our application, the ROV spends a lot of time sitting on the deck between dives. Trickle charging while the ROV is idle on the deck would amplify the benefit to our overall dive times.
I’ve flirted with the idea of using a pair of Vicor DC-DC converters to DIY this style of topside charging. But those things are too expensive to just cross your fingers and wing it with the specs.
Please update us when your system is available! There is a definitely demand for a lower cost/complexity topside power solution.
I always encourage people to learn by doing. Be careful obviously, and I would stay at 24V or less until you’re comfortable building and testing the circuits. 400VDC (and even 120VAC) can kill, and it makes for some excitement when things are not properly wired, but 24V is much more manageable. Always take appropriate precautions on the battery, as you can easily start a fire with the amount of current those packs can deliver. If you have a specific question, feel free to ask.
