S800 and 5S lipo's ? Anyone running 5S on their S800?

[Aerial Media Pros]

I was curious if anyone is running 5S lipo's on their S800. I have a bunch of 5S 8000's that are for my sky jib . I was hoping they would be ok for the S800. What would the downside of running 5S on the S800 be? I'm looking forward to see what some of you think about this.

 

[BorisS]

A the moment we are all i little worried about random flips of the S800. First guy came about 1 month ago and noone really believed him and that second guy who had a little more calm approach to the problem so people started listening now the third guy also had a flip in normal hover and GPS mode and we are getting worried.

A lot of use are concernedabout the ESC temps that we get and are speculating that the cause might be a ESCs failure.

This is also interesting. http://www.rcgroups.com/forums/showpost.php?p=21985434&postcount=38

Concerning the S5 question i would probably not try it or recommend it at the moment given the possibility that the amps might be increase compared to 6s eventually adding more stress on the ESCs or on the wiring.

Boris

 

[DennyR]

Lower volts usually means higher temps. Thats why your average big 3D heli is 12s/ 45 volts. I would expect heavy lift MR's to go the same way eventually. The other problem, will be that by going to 5S, you will cut down the available rpm which will certainly effect your stability to the point where you may not have any.

 

[Ghostrider]

DennyR is correct about 12s setups being more efficient than 6s setups on a helicopter because the higher voltage means less amps to get the same wattage. Wattage equals power. You have to decide how much power you want and design the motor around it and the voltage you want to run. If you try flying that same helicopter on 11s though, you end up reducing the voltage, amps and power, but gain efficiency.

For example:
12s pack = ~50v
50v x 50a = 2500w

Go down one cell using the same motor might look like this
11s pack = ~46v
46v x 46a = 2116w
You lose voltage, current and wattage

If you want to get back to 2500w using the 11s battery you need a different motor that is higher Kv and higher current draw
11s pack with higher Kv motor
46v x 54a = 2500w


So the same would hold true for the S800. If you try 5 cells, you will reduce current, but you also reduce the lifting and stabilizing abilities. If it flies smoothly and with authority on 5s it will be slightly more efficient and should produce less heat. The speed controller should be happier with this.

Tim