Cr0sh, thanks for the point of view on batteries and would you still start with acid, if you did not need to worry about budget?
If I didn't have to worry about budget - then I would probably start with the drop-in replacement LiFePo batteries you can buy now that are meant to replace same-size SLA batteries; typically, they are much, much lighter, have larger amp-hour capacity, and most importantly, they have the built-in controller to charge the cells properly off fairly standard 12 volt chargers which can be bought anywhere automobile parts are sold. Also, the LiFePo chemistry is considered safer (fire/explosion hazard due to shorting, over-charge, etc) than standard LiPo.
I would not go with my own custom LiPo solution - because then you are looking at cost issues (and possibly problems) associated with charging the cells properly, and all the other issues. If you had somebody who understood this on your team - that you could delegate that part of the system to, then that would be a different thing (you might then potentially save money). But - if you are planning on doing this using mostly COTS components - then the mentioned LiFePo solution would likely be best.
That all said - if cost was a factor (and I now understand here it isn't) - SLA batteries are great for this kind of purpose. They are proven capable and reliable for use in electric wheelchairs, where they can last and run for many miles between re-charges, and they are easy to design a charger for as well.
Just so you know - I have been a volunteer for this organization for a couple of years now, and have learned tons about electric wheelchairs, and what they can and can't do over that time. They are some of the most robust machines for helping people on this planet - we actually find them perfect for robotics platforms when we need something heavy duty.
Interesting idea about the wheelchair but I was looking for something more low profile.. even if it costs more.
Definitely, though, look into at least the motors - they are some of the most durable and quietest motors you can want - and some of them actually have fairly low current draw. The only downside is that they are 24 volt devices, but that only matters when you need to charge them; you either make a 24 volt charger, or you build or buy a 12 volt balance charger (they make such a thing - but they aren't cheap - we used one on a custom art car we made for Burning Man that used 4 extremely large SLA batteries meant for a telco UPS system - it was running a 36 volt golf-cart motor - we could get that thing to do 40 MPH!).
I do love the tank style of movement but I was concerned about the power loss and reliability from reading forums but maybe I'll give it a shot because I would rather go for the better long-term goal.
With any skid-steer system you'll have a power loss - especially if doing panning-style or single-side running turns; losses are less if you do proper forward-motion turns (where you're running both sides, just one at a slightly slower rate, the total difference in speeds, of course, being related to the rate of the turn).
Reliability is only really an issue on a tracked system - unless you purchase actual tracks (for this larger scale robot - if you want tracks - and since this is a work project: Use snowblower replacement parts for the tread system, or look into those custom track systems meant for 4WD off-road trucks; a couple of those, while very expensive, would make for one bad-a$$ machine).
Thanks for the advice with the H as well and this is for a work project, so I don't need to worry too much on budget.
Then stick with Vantec (http://www.vantec.com/) or Roboteq (http://www.roboteq.com/) - trust me on this, both companies have awesome and proven products.
My friend Lance at Wheelchair Labs has used Vantec controllers in the past - they are very capable controllers, though not as "polished" as Roboteq's offerings (but the difference in price is insane - but you get what you pay for, and Roboteq's controllers are top-notch in that).
I'm big on safety, so I'll give it a fail-safe system but I was not even thinking about that.. haha! I guess I did't expect a danger in this. Too funny just the image of a wheelchair or robot going ape $tuff.
Yeah - the image is funny - until it happens to you! Ok - it can still be funny then, provided you have insurance (property and/or health and/or life) and pain isn't an issue. But seriously - design this part and test it first. Don't try to "do it later" and "patch it in" - this is why so much "security code" in software development fails, because the systems weren't designed around the proper needed security, and it was attempted to be patched in later, resulting in a poor and buggy implementation. I've seen it too many times in my software development career. The same design strategy unfortunately happens in hardware, too. Do it right - give it thought, put it in at the beginning, and test the hell outta it - then work on the fun stuff.
I plan on using the 1/10 or 1/5 scale first.. I wouldn't want to ruin electronics or parts that are too costly but by knowing everything required at my ultimate goal, I'll be able to scale down a prototype. Awesome advice though!
Prototyping is one of the best ways to test your ideas, and to learn what works, and what doesn't. Since this is a work project, you might find that a Lego Mindstorms kit might be a good prototyping investment. Or - if you want something much more professional (but not as easy to get in the States, unfortunately) - look into Fischertechnik. It isn't a cheap construction system, but it isn't really a toy, either. You can build actual functioning systems with it; it is used by universities and such to teach mechatronics and other engineering practices. As such, though - it isn't cheap.
Another option would be stuff like MakerBeam (and other small-scale extruded aluminum t-slot profiles) and/or ServoCity's prototyping and robotics building stuff...
I'll look at the resources that you mentioned and what do you think about this one that I have been reading? http://www.amazon.com/Arduino-Kinect-Projects-Design-Technology/dp/1430241675/ref=sr_1_1?ie=UTF8&qid=1443729175&sr=8-1&keywords=arduino+and+kinect+projects+design+build+blow+their+minds
TBH - I haven't seen that book before, but I have been impressed with that particular publisher's other offerings for other authors about the Arduino and robotics. I'll have to look into it.