hello big brothers

[dreamflyer]

can you guys teach me how do i judge which batt wil be good for my motor like which one is too weak which one will over kill?i flying a king two...wanna change motor to brushless 3800kv....so which batt i should get?a bigger c or bigger mah?i see ppl asking for 2100mah?too big?

[xwing]

erm... dude. i don't know whats a king two..

but generally what i have here should apply for most setups.

1.) if weight is a concern go for the battery that can supply u with enough power. meaning if you need 10A go for one that can easily push out 13-15 amps. So you won't kill the lipos.

2.) The bigger the battery = higher endurance theory does not neccessary work. Unless its really a floater. Why cause if the plane is heavier you will need more speed to keep it flying... which will = to higher throttle setting... which means lesser flying time... so in the end it will be back to sqn 1.

3.) 3800kv seems like a high speed motor to me... you're going for speed? or gearing it down?

hope this helps.

[dreamflyer]

thanks bro...flying a helicopter....heli do have big motor i realise....sure does help alot...now i know how to calculate which batt for which motor

[johndyl]

generally there is no right batt. u just have to make sure the batt can supply enuff amps for the motor and the weight doesnt throw the cg of the heli off.

so the best advice is to follow the king2 thread and use the tested recommended batts, which will be abt 150+g TP prolites(15C) or DN Power(20C) ard the range of 2100mah

[tucfaz]

Remember myself asking this question 3 months ago.. when I was a total noob.. and can't decide if I should buy a 2200mAh 10C batt (Cheaper) or 2200mAh 20C Batt (More expensive), as I ask myself, but same capacity what?? but what the hell is 10C or 20C??.. and why the price difference..

OK.. What I've learn.. Putting it in layman terms.

Higher C rating gives you higher discharge. Hence, more power.
Higher mAh rating giving you longer flight time. ie, 1000mAh = 5mins flight, 2000mAh = 10 mins flight (Numbers are for example only)

It's important that you get good quality Lipos, as cheaper ones (not going to quote any brand here) will usually over spec their batt rating.. ie, Label say 20C, but actual rating 15C. etc.. Hence, when you use these batt on a heli with a 3200Kv motor with a 40A ESC.. Then your batt will bloat just after less then 5 flight, and this is basing on my personal experience.

Low end VS High-End lipos.

Brand X = $79.00
TP or FP or Poliquest? = $100 -+

Price difference is +- $40..

Brand X bloat after 5 Flight, and loses it's power after close to like 50 flight.. But higher-end batt will maintain it's power way beyond 100 flights..

Guess you can do your own math from here.