RCU Forums - View Single Post - Welcome-the not so scale, almost ready to fly, soon to be scrap, Warbird Brotherhood
Old 11-25-2014, 05:59 PM
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sparky4lawndart
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Originally Posted by Katniss View Post
I'm sorry to hear of the extensive damage to your Zero. It seems odd that both 2s lipos would fail at exactly the same time. Ive had fully charged lipos sit for months and be just fine. I use lipo batteries for my TX and the only time Ive seen a problem is when they are over dscharged. If I leave the TX on by mistake and it drains the 3s lipo pack too far, it generally wont recover. Sure, you can put a charge on it, but then it wont hold it.

My guess is, the HV servos you've got installed are drawing a combined amount of power exceeding the capability of the 2s lipos to maintain a constant voltage...thus your receiver hit brown out level in flight. The discharge draw from the overall servo load was pulling more then the 2s could provide without causing chemistry imbalance inside the cells. Im guessing this as it doesn't seem likely two separate batteries would fail at the exact same time or even close to each other unless the current draw was so high. Or...vibration in the plane could have caused a short....I don't know.
I personally don't use lipos for rx power. Almost every warbird I've built has required weight to balance so I use nimh packs as they are heavier then lipos. It is just my preference. I'll also run one battery through the battery port on the RX and then y-harness in another one usually through the aileron channel. Each battery has their own on off switch. I used to run both through the same on/off switch and merely had them paralleled, but was advised against doing that by another club member.
I don't know how you had things set up, so please don't think Im preaching.

As far as replacement plane....the Top Flight GS Corsair is a nice plane. Ive seen one in person and they look really good in person. My friend set his up on a 12s lipo power system. That plane is so graceful and lands so slow I couldn't believe it. I think it would be a great choice!

Thanks Katniss... The redundant 2S lipos on separate switches were for the rcvr only... I've checked the system on another set of 2S lipos and the current draw is even on both packs ( max 1Amp flipping the servos out - feature in the Futaba radio - it cycles all the servos rapidly and within the endpoints). These were square 2S 2200Mah rcvr packs and I think its likely a short in the packs (I had them zip-tied together and Velcro strapped in tight). My fault for not load testing them after they charged that morning...

Yes, I'm a big believer in NiMh packs but wanted to try out HV on this plane.

No, I don't think you're preaching... I dig your input!

No, I won't pick the Hangar 9 Corsair only because they've (Horizon Hobby) taken me for a ride 3 times and that's my limit...

Yes, I like the TF GS Corsair... I just bashed one for a friend of mine... DLE55RA w/ Bowman ring, Robart air mains, static tail wheel, painted pewter gray with a black gun hood and white feathers, Callie Graphics did up the Quantico decals... very fast and looks good in the air... He wants me to do another one in a Korean color scheme... Black with red on the tail, same motor & setup.

I wish I could post pics again... apparently 20 years of IT experience won't let me overcome ActiveX controls in my browser.