Power issue with home plug


#1

Just finished building a 2.6. When I plug it in all I get is a green light and a yellow light on the rov board. And the power ans Ethernet light on the top side home plug. At this point if I unplug the home plug board on the rov everything will power up. Then it’s a 50/50 chance that it will stay powered up after I plug it back in. I have 5v on the teather.

Any ideas. Thanks

Tom


#2

Also I am using standard C batteries for now. I have 6v on each side. Is this correct?

Thanks
Tom


#3

Hi Tom

C batteries will not provide enough current to power the ROV you need higher current source batteries or you could test with a car battery but you should use a 15A fuse to protect against any accidental shorts. You need +12V on pins 5&6 of the DB25 connector.


#4

Thanks David, sorry for my ignorance but I’m still a bit confused on the batteries. Looks like on the site you can buy a set of 6 batteries. That would be 3 batteries in each tube correct? Wouldn’t that be 9.6v. I’m sure I’m just missing something. Also I have read some post where people seem to be using disposable batteries. Thanks again. Tom


#5

Hi Tom

The ROV will work down to 9.6V but you need the high current capable batteries. They have started using a new battery that does not have the current protection circuit built in as was the case for the trustfire battery so please check the form where they talk about the new batteries. I don't have that info at my finger tips.


#6

Hi Tom:

The current vehicle is wired to use two parallel packs of 3 Lithium batteries in Series- either LiFePO4 (nominally 3.2V each or 9.6V total) or LiMn or LiCo (nominally 3.7V each or 11.1V total). You can power the vehicle with anything between, say, maybe 8V or 14V and it will work. The biggest issue is providing sufficient current- during a full-power drive the ROV needs maybe 15 Amps or so of current. Alkaline "C" batteries and most people's bench-top power supplies can't provide that amount of current, no matter what the voltage is.

The very earliest OpenROV designs used "C" batteries. The two battery packs were wired in series, with 4 batteries in each tube, to provide 12V. This design sort-of worked, as long as you moved very slowly, and for only a short period of time. The rechargeable lithium batteries are considerably better.

-W


#7

Thanks Walt, That clears it up. I have a 13V 15amp power supply and hooked it up with that for the testing. Got everything working! Now I’m just waiting on the batteries to do my first dive!! Thanks again for the replies.
Tom