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Voltage vs capicty

Posted: Tue Mar 29, 2016 6:26 am
by murankar
What am I talking about? It's rather simple but I don't know how to figure this stuff out. I have been on 3s packs for almost 5 years. Never needed anything bigger than 2200 3s packs since my 3 helis have been typical 450 class helis.

Now that I have the X3 and needed new packs I decided to go with 4s packs @ 1800 mah. Now these packs are in some respects smaller. I am now left wondering if I should have looked for 2000mah packs.

So I guess the true question is "how does voltage affect capacity?". With higher voltage you naturally use smaller packs in capacity. For this kit a decent 6s pack is about 1350man to about 1800mah, depending on what frame you have.

Now I need to see how this changes my flight times. On the 3s I was averaging about 6-7 minutes. Next is to fly stand fund out.

Re: Voltage vs capicty

Posted: Tue Mar 29, 2016 3:55 pm
by Lee
Higher voltage means less amp draw. But the pack is heavier so reducing the packs capacity evens things out again.
In the end, flight times should be comparably similar.
All thats really changing, is the electronics run more efficiently with the 6S battery.
Less strain on the motor,ESC.

Re: Voltage vs capicty

Posted: Wed Mar 30, 2016 5:22 am
by pvolcko
You will see some reduction in current draw with the higher voltage, but probably not equal to the relative voltage increase. That is to say a 1/3 increase in voltage will not mean a 1/3 decrease in current.

What will the relationship be? Don't know. It depends on the motor and your setup (headspeed, gearing, blade size, etc). Probably plan on half or 2/3s the change in voltage, so in this case a maybe a 1/6 decrease in current. So if you ran 2200mah 3s before, expect a 1800mah 4s pack to have the same endurance.

So I'd say you're on the right track with your selection. Hopefully you'll be surprised and end up gaining some flight time.

Re: Voltage vs capicty

Posted: Wed Mar 30, 2016 6:19 am
by murankar
Thanks for the input.

As for the setup, castle 50amp edge, castle 10 external bec, scorpion hk 2520-3500 with an 11t pinion. I would like to see how the 4s 2200 work. So far 2000 are unlocated. Next winter I hope to go full 6s.