Battery selection

[trent.zx6r]

I am currently running a 6s system in a 550 size helicopter. The batteries that i have been using are 2x Hitronex 3s 4100 mAh 11.1V 3s1p 50c. I seem to keep cooking these batteries, i try to land at about 70% discharge, let them cool and charge again. however after only a few flights one of the two packs gets hot and expands at this point i am binning the battery and replacing with new. I am now at that point again of needing to replace the batteries and thought that a change of battery is the way to go. I noticed that flight Test use Turnigy batteries. I have been looking at the Turnigy nano-tech 5000mah 3S 35~70C Lipo Pack, These seem to be the about the same price as the other batteries that i have been using but what are they like? are they reliable? Flight Test: Why do you use them? Any in put would be great thanks.

 

[Carbon]

Yikes! Nano-techs are (in my experience) crap. They are horribly over-rated in the C rating and I have never had a battery puff except two nano-techs in a Bixler (a glider that draws like 0 Cs). The Turnigy lipos are very reliable and I bet they will work for you. Also I would looks to get a higher C rating if you are cooking batteries..

 

[trent.zx6r]

thank you Carbon for your input. i was told that they puff due to a cell becoming hotter than the rest, this can be cause by ambient temp as well as current draw. could this be a issue in the bixler? being that the battery is enclosed? i guess that, as you said there is minimal current draw so the battery should get that hot. not sure what to do really.

 

[Carbon]

With your Bixler the amp draw is not nearly enough to cause problems. I fly mine with a 20c 2200mah Turnigy batteries (I have 6 and often speed charge to cycle through them) and it never gets hot even in the closed battery bay. Yet for some reason the nanotechs died after only a couple of charges. On a heli I suspect that your batteries are being ruined by amp draw. This may be caused by the motor drawing more than normal. I would check the bearings and make sure there is nothing in the motor like dirt or dust.