RadianPro Battery question

[flyeruk]

I have just picked up a Radian Pro.Can anybody tell me if 4s 1800 Lipos could be used in this glider?
Reason i ask is i have a load of these batteries and only a couple of 3s lipos.Just trying to use what i already have if possible

Edited By flyeruk on 06/01/2019 16:59:00

[Former Member]

[This posting has been removed]

[Denis Watkins]

The Radian Pro, flyer, will pull from your hand at launch from a standing start with a 3s

And go like an arrow, climbing steadily on the 3s lipo

So No as Percy recommends for 4 s, and the 4s size, and hacking the battery box out and the extra weight

Edited By Denis Watkins on 06/01/2019 19:08:21

[Brian Hammond]

Definitely 3 cell 1500 to 2200ma

[flyeruk]

Thanks for the replies.3s it is then.

Edited By flyeruk on 06/01/2019 19:13:16

[flyeruk]

Just one other question if i may.This is my first glider.Im not looking to hunt thermals or go to high,eye sight lets me down there,what sort of flight times should i get just general sports flying?

[Brian Hammond]

It all depends on conditions but with 2200ma Lipo 30 minutes is easy and if your eyesight is,nt too good that will probably be ample, I know it is for me!

[PatMc]

Posted by flyeruk on 06/01/2019 16:58:21:
I have just picked up a Radian Pro.Can anybody tell me if 4s 1800 Lipos could be used in this glider?
Reason i ask is i have a load of these batteries and only a couple of 3s lipos.Just trying to use what i already have if possibl.

The answer is - yes not a problem so long as your ESC is rated for 4s but you will need to use a smaller prop. Using a prop on 4s that keeps the current at or below that taken when using the original prop on 3s there should be no overheating poblems.
If the current drawn on 4s when using the smaller prop is 3/4 that drawn on 3s with the original prop then the power (Watts) will be greater. But because the smaller prop is less efficient the actual thrust will be less.
If the current draw is the same then the power on 4s will be 1/3 greater than on 3s. There will be an increase in thrust but not by the same proportion.

Re the battery size & weight, a 4s 1800 should be the equivalent in weight to 3s 2400 but in practice there's virtualy no difference in weight or dimensions between, for example, a Turnigy 4s 40C 1800 & Turnigy 3s 40C 2200.

[John Robertson 3]

Regarding "what sort of flight times should i get just general sports flying?" - with a 3S 1800MAh pack, on a calm day, with no thermal activity, I can drift around and achieve 30 minutes without problems. If there's any sort of favourable light wind on my forty-foot-or-so slope this figure goes up significantly. 45 minute, and plenty charge left in the pack.