Battery/ power Options??? Help

[SeniorDesign]

My senior design class is building a ROV to go about 200 or more feet into the Ocean. Currently with all the componets in the ROV we are pushing around 400 or so watts or power and 40 amps at full power with everything runing at one time.

Right now we have a DC -DC regulator that puts out 12v at 700watts and 50amp max witch should be good enough to power the componets. Inlet is 9.6 to 14 volts/ <200mA

Problem is how do we get power to the regulaotor? My proffesor wants to stay with DC power because of expenses, so right now we need a power source topside or run a on-board battery to the regulator?

Any opinons or other options would be greatly appreciated and the user will be mention in our presentation once all said and done.

[Alaska Rov Systems]

Can you hook it into a boat's ac generator???? either that or shore power??? maybe a very powerful inverter but your gonna need a lot of heavy duty batteries. Plus you have to calculate the tether for voltage drop. and make sure that you have the correct gauge and enough amperage to power it at 200 ft.


Alex Stuart

Alaska ROV Systems

[SeniorDesign]

Right now we have a 24v 1000 watt Dc power supply topside that is gonna be plugged into the standard boat ac outlet. We are running two 8 gauge wires down through the tether both postiive and negative. the calulate voltage was 6v through the tether. But still the volatge input into the regulator would still be too high.

After read a few thread on here about on board batteries. My team and the controls team were thinkin about us doing the lipo batteries. and getting enough to have 12v at 30 amps. if we get two 15000mah batteries an run it strait to the andruino board would that power our ROV for about an hour??

Our can we get enough lipo batteries say 11.1v to plug into the regulator (input 9.6-14v.. nomore than 200ma input) ***also the stepup regulator is inside the ROV***and run that for up to an hour before its drained??

Unforuntatly our budget is small this semster because we are picking up from where another team from last year left off.

Thanks

[Seawolf]

My AUV uses a 12v, 15AH lead acid battery. It weights 10 lbs and fits nicely inside a 6" diameter PVC pipe. Something like this: http://www.mouser.com/ProductDetail/CSB ... 6Xang58%3D

We reduced our power requirements by only having 2 thrusters active at any given time. (we have 6 thrusters total). With this simplification calculate a battery life of about half an hour (constantly running 2 1000GPH pump-based thrusters at 100% output). We haven't really been able to do an endurance test yet, but we expect to get longer run time in the real world, because you really don't need 100% output all the time.

That should help put that battery thing into perspective. Remember, the amp-hour rating of the battery depends on the current you're drawing from it.

[Alaska Rov Systems]

ok so i have started calculating everything:
with the 24 volts at 1000 watts you get 41.67 amps.

How long is your tether?

the dc-dc voltage regulator - 12 volts at 700 watts gives you 58.33 amps.

why are you running it through a dc to dc regulator??? Also what Seawolf said was correct. As long as you don't leave to propulsion system on too long you should have enough power.

what kind of propulsion are you guys using??? You should also calculate resistance of each thruster and amp draw and input that into the equation.

Alex Stuart

Alaska Rov Systems

[SeniorDesign]

The tether its self is 250ft long from beginning to end.

The regulator was bought by the previous team.. thinkin that they need a constant voltage and current supply inside the ROV since there was gonna be voltage drop across the tether.

They calculated that if everything is running.. such as 6 thrusters 4 camers and 4 LEDs that it would 30amps. but its unlilky that evrything would be on at onen given time because of cameras and LEDs will only be on one at a time. Same therory for the thrusters. So they calculated minimum amp draw to be 9 amps.

We wanna get rid of the power suppy completly if that possible and just get on board batterey enough to sustain electonics for atleast half an hour.

We feel like the power supply and regulator are wasted money that the last team just threw away and now our budget is down to like 100 to 200 dollars beacuse of that.

Thanks for you alls input so far.

[Mareike]

I use 10ea 12V 9 Amp Batteries from home alarm systems, they fit into a 150mm pipe and will be used as well for the ballast.. got then for about 18$ each,..