mneary said:I should chime in here that a deep-cycle marine battery may be overkill. 12V 7Ah sealed lead acid batteries aren't very expensive and might fit inside your ROV. Of course you'd have to shed a lot of ballast. I don't know how big your ROV is, but in the end a small SLA should weigh (and cost about $22) a lot less than 100 ft of 14AWG stranded wire.
I have looked into the SLA's but I guess I'm under the impression that I wouldn't be looking at very much runtime. There's an SLA I was looking at online that is rated at 18Ah for $53. Now does that mean that it will provide 18 amps of current for 1 hour of continous operation?
If I ran all three of my motors and both lights continously I will be looking right at 18A. In reality though, I would just be running the motors in bursts and most likely only two at a time. However, the 50w halogen lamps I'll be using will draw 3 amps each continuously as long as they are switched on.
If I can come up with a way to build a pressure vessel for the battery then I will probably end up going this route. Even better, if I had $120 for a marine gel-cel battery I wouldn't have to worry so much about waterproofing except for the terminals.
Thanks for the feedback!
Pcolaboy