Yeah, Thats all good, but my esc is rated at 400 amps, the motor pulls more amps than the battery array can provide. The crux is the Amp availability.
Sounds like somewhat unrealistic or flawed design goals. Unless the project is top secret, you may get more help providing details of just what your gizmo is designed to do.
Um… yesterday
now
those number don’t really relate to each other in any obvious way unless you can elaborate.
if you are really trying to design a robot with a 6hp drive train this probably isn’t the best place you can go for help… that’s more like a heavy weight battle bot chassis not a educational or hobby robot design.
Well, obviously the design is evolving as we discuss it. It’s not top secret, but I would like to maintain some sense of confidentiality. The project involves designing a rugged, 4WD, rapidly deployable, Wireless UGV with PTZ video capability for a variety of applications. My current design is a teleoperated Ruggedized RC Truck with a PTZ camera and the ability to drive out to 700 ft, sit for 6-8 hours while the operator records the video. The UGV needs to be able to PTZ and transmit live video/audio during those 6-8 hours. I would also like it to be strong enough to climb over a city curb, or pull 60 lbs of gear.
The 1 Watt Video transmitter consumes only 500mA,(12Vdc) but the 12Vdc Motor pulls a ton of amps while driving over rough terrain and loaded with 15 lbs of video gear and associated batteries. Its hard to say how many amps the motor will draw, but I’m willing to bet its in the range of 100-200 amps at peak! The 2 pan tilt servos i’m using are HS-5745MG (250 oz. in.) Digital Quarter Scale Servo ( Amp draw 3mA/idle and 700mA no load operating)
So, one of my questions is: What type of batteries would be the ideal for this project and can last 6-8 hours for the vehicle, camera, PT servos, and video transmitter?
honestly I’d probably just go for a sealed deep cycle marine/rv coach battery rated 30-40AH or so (which is a smaller one). relatively speaking it’s low cost, low maintenance, easy to charge at high rates, it’ll do the 200A when needed, and you can probably buy them locally. it’ll be about 2.5X the weight of a Li-based pack of the same AH, about 1/10 the cost, roughly the same size, and without the headaches.
Batterys? I’d say deep cycle marine made for trolling motors and such. The motors you referenced spec at ~600-800 watts, which would probably pull ~50-65 amps at full load. That would probably make your 2.8AH battery pack melt like it was dead shorted. I think you are chosing inappropriate motors for your bot. Your motors are high speed motors which are appropriate for RC racing setups, not for surveillance bots (kind of like trying to plow a garden with a Ferrari). Most successful commercial/military bots incorporate slow deliberate movements to allow for better remote control (unless your bot will just be another RC vehicle).
Another question I have is: how can I keep the batteries in my Futaba T7C radio from going out while running this UGV for 6-8 hours. Right now I have the stock 9.6 V Nicads. I would have access to a 12 volt car battery. Is there a cigarette lighter adapter I can use?
C
What did the UBI2590 set you back? Just curious as their website only offer to provide a quote.
359ea
Gulp…
think about who the principal customers are and it shouldn’t be too surprising. 
here is a link to an interesting video from a company that makes LiFePO4 (lithium iron phosphate) chemistry cells comapring the effects of a Li-ion based BB-2590 vs a BB-2590 built from their cell technology… taking an M-16 round
of course they don’t strongly emphasize that the energy density of their cell design is not enough to allow them to actually meet the cerdec specification for a production bb-2590 that the military can use. 
Thanks, Good to know
C
Great video Eddie. That battery turned in to a flame thrower.
…I’m off to shoot some batteries now 