4s vs 2s (x2) in Series
 

I'm currently in the process of rehabilitating an 1/8th scale RC8e buggy for the upcoming season and I'm trying to decide how best to power it. I'll be running a Tekin RX8 esc with a T8 1700 motor using some sort of 4s battery (or combination).

Question is: Is there any real difference in running a single 4s battery vs. a pair of identical 2s batteries (in series)? Using 2 batteries allows me the option of using them in my 2s vehicles but I don't know if there is a performance loss using 2 batteries vs. 1.

Yes, there is a difference, primarily due to the fact that you can get hotter C ratings on 2s packs than what's currently available in the 4S range. With some of the 2S packs claiming 100C ratings you're gonna notice quite a bit of punch over their 4S 50C-65C counterparts.

Your 2s setup is gonna be a bit heavier by roughly 100g over the single 4S brick setup. If you have nice 2S packs already then I'd run those. Personally I run a 4S setup, Thunderpower and SMC, and love the feel of the car, very planted.

IMO the punch from the 2 2s packs will make up for any weight difference!;)

another pro for 4s - less power loss thru heat from only using one plug.

another con for 4s - if you have a problem with one cell, you just lost a 4s pack, if you loss a cell in a 2s then obviously you only lose a 2s pack.

another pro for 4s - smaller size if you are running hard case batteries.

Double post sorry....

Physicaly speaking, there is only a 35g difference the new thunderpower 4s 65c single battery and 2 of their new 2s 65c batteries, both 5300mAh.... Most of people use more weight then that to balance their vehicles....:rolleyes:
You still have to add the weight of the few extra inchs of wires and assorted terminals, but I think that would minimal...
The only thing that may add more weight is if you decide to rework the chassis to mount the two batteries in different locations.....:sneaky:

Suggestions for best minimum battery stats for the applicaion I mentioned? Don't know if I want to spend $250 for a 150 battery (daddys got a budget)so what would make the best 2s combo - for the money?

Gens Ace has probably been the best bang for your buck that's ROAR approved. It's out of stock everywhere though. You can also look at the Turnigy lipos at a cheaper price but not ROAR approved. If you're just doing the casual club racing and some bashing, the Turnigy are your best bet.

Gens Ace - hobbypartz.com
Turnigy - hobbyking.com

I bought a venom 5000 4s pack for 100$ if you buy two good even just 40C 2s batteries your going to be spending 80$ per battery and that is venom stuff, good thunderpower batteries 65c run around 130$ a piece its all on your budget, I think that venom 4s i run is plenty fast and has plenty of punch i only run my radio on 65%

check out hyperion or Voltz at readyheli.com

I suppose this may sound like a dumb question to some but do you really notice a big difference in performance (for local club/competitive racing) between a 40c (constant) 50c (peak) battery and a lets say a 65c or 150c battery? Considering you can get a 40/50c for about $25 from Hobbyking and the others start at about $130. Never having run more than a 25c I just wouldn't know. Let me know. Thanks.

Sometimes there are very noticeable differences. But only from say, 25C to 40C. Not necessarily from 50C to 55C. And it also varies from company to company. One company's 40C may be equal to another's 50C.

The difference will be noticed in punch.

I.e. 25C is like a garden hose and 50C is like a fire hydrant hose. You just can't pull enough power quickly with 25C. Rather, you can pull more power effectively with the 50C.

in theory no. the C rating merely states how much amp pull the cells can handle. so if you know that your buggy peaks at 150amps during start up you will need a battery that can handle that. A higher C rate should have a longer life span, but not really give more performance. some people say they feel a difference, tho.

So would one of those 40c jobs from hobbyking be sufficiant for my rx8/t8 1700 esc motor combo to avoid issues when I have to get on the throttle hard?

You should have no issues. I've used it on a Castle 1800kv as well as a HobbyWing 2000kv and it worked fine with both.