QUOTE: (BrianG:
For reliability and warrenty (should you need it) reasons, I would select the model that matches the voltage you plan to use. The 16018 might be able to handle 8s A123's, but would be pushing it.
As far as the current rating is concerned, I would think the 16024 would be the way to go. At 8s A123 and 160A, that's over 4,000w (~5.6Hp)! Besides, I think the A123 cells will be the limiting factor current-wise.)
- Thanks BrianG. I think I get the point, lol, I hadn’t considered the A123s to be the limiting factor, but it does make since as their discharge (amp) rate is less than a higher quality li-po.
QUOTE: (Finnster:
You should just be able to do 7S A123, but 8S is one cell over. Remember that A123s charge to 3.65V, while the controller is rated @ 25.5V max IIRC.
If I was choosing between the two, I would always go for higher V if its an doable option. w/ that hvy a truck w/ and XL motor, you will find you will be fighting motor heat before you hit those current limits. In fact I don't really see the point of the 224/18 controller w/ A123s. Even in 2p they recc no more than 140A max. I would aim for ~120A peak. With 7S A123s, that should be good for over 2300W. If you get a high eff motor, like a neu, that translates to alot of power to the ground. If you go to 9S2P (if you could even fit that on :) ) you have ~3000W. 18cells is alot of frickin cells tho. After a certain power level the batt just starts getting huge.
ZPB has a 7S2P A123 with a neu on his maxx and seems like a very strong setup. Perhaps he could shed some light.
Edit: Kinda contradicted myself there, but point is, more v is always better than amps (224A is silly imo, other than to keep a very cool controller) but you will be practically limited by the A123s if you go too high a cell count with still healthy amp draw. ~14cells is the practical limit else I'd be looking at hi end lipos. ==> 16018 would prolly fit the bill, unless you wanted to really push it to 8-9S on the 16024. How much power do you really want?)
- 3.65v, very true on those A123s, should have factored that into my equation, that said, don’t they level off rather quickly after a charge vs a li-po “holding” peak for a bit longer, if that’s the case that may give me some “safety margin” a quick heat up of the ESC at peak, followed by a leveling of current in the packs and a cooling off of the ESC (theoretically)… That’s kind of what I was thinking, take the higher voltage route of the 16024, keep the ESC VERY safe for the moment and then climb up, or be able to climb up in cell count (or convert to li-po) sometime in the future. As I need it\want it. For now I’m looking for a setup that will yield a solid 40 +\- mph out of my fat pig of a Savage 
I’m also hoping to be able to put the thing on a diet once it’s built and I determine where I can lose the weight, lol…
QUOTE: (Crazyjr:
I agree with BrianG. All those numbers on voltage are theoretical, till you plug in and see if you get smoke . At 3.65v, thats close enough to the nominal 3.7 of the LIPO's to consider the S count similar)
- Fingers crossed we get no smoke as long as I can control my urges for MORE POWER!! 
All in all I’m getting the idea that if cash is a consideration I should go with the 16018 and keep my cell count to 7S2P with one of the NEUs. If cash is available then I should go with the 16024 and have room to grow 
You guys rock, thanks again for the solid input and keep me posted if anyone has any other GREAT ideas!!
ZPB – Anything you’d add?? Seeing Finnsters note on your Maxx I’d love to have your input here. – Thanks!
Thanks again,
purp