Originally Posted by KC10Chief
Talk to me about the latest thoughts on 3S vs 4S for this frame. Currently, I am running 4S on mine with the 750kv Turnigy NTM motors. I have a full FPV setup on mine. ready Made RC 1.3G video gear, EzUHF, EzOSD, Naza, etc. The thing flies fantastic. However, I don't get very long flight times. The biggest battery I can fit in the slot, is a 2800mah 4S battery. When I had all of this stuff on my VC-450, I was running 3S with a 5000mah battery underneath. I could get 12 minutes of flight time with those batteries.
So, I was thinking of switching my FPV frame back over to 3S and running the 28-26 1200kv NTM motors. I could fit a 5,000 or even a 6,000mah 3S nano tech on this thing. A 6000mah 3S nano-tech is only 6oz heavier than my current 2800mah 4S GeForce batteries. I realize the motors would work harder than my current ones, but my goal is to get more flight time! I live in Alaska. Motors don't get hot here, especially this time of year! I don't do any kind of aerobatics with my FPV quad. Am I missing something here or is 3S a better choice for more flight time?
Just to share my experience, when I was selecting components, I specifically went 3S for higher capacity and lower weight at the expense of thrust. I would have thrown a Zippy Compact on there if they'd had that in stock.
With a full FPV payload and a 5000mah battery, I'm pushing about 1600 AUW and with 8x4 props - this thing is a pig powered by mosquito wings. I flew this at 1300g and obviously, lighter 300g it was far more nimble.
I was doing a tuning run yesterday and I got somewhere in the neighborhood of 16-18 minutes (lots of low amp activity). I won't be winning any speed contests with this rig, but it's performance has been acceptable.
Some of the guys I fly with fly with 3300 mah batteries on similar kv/weight setups and they get around 8 minutes. My only issue with the Nano Techs and even A-Spec options is the power to weight ratio. If my intention is a lot of low amp runs, all that extra voltage overhead is wasted and that comes at the expense of weight and consequently flight times.
What I'll be looking at in the future are these new crop of ultra low kv disc type motors with big fat props, but those are pretty spendy right now at nearly 3x the cost of an NTM 1200.