Serious questions on my set up...CC says DANGER!

[WhatRLaws4]

I just got off the phone with tech support at Castle Creations, and Im curious is their recommendation is needed or just playing it safe. I converted my Venom 58" gas KOS to FE using a Leopard 5698 910kv, the Castle Creations Hydra Ice2 200HV esc with 5.5mm bullets installed, and Ill be spinning a X452. I just got my turnigy 4s 5000mah 40-50c lipos today. I was going to run 2 4s packs for 8s 5000mah. Castle says that the esc could blow using this 5000mah setup. He suggested I use 4 4s 5000mah packs. 2 in parallel for 4s 10000mah then connect both in series for 8s 10000mah. I had thought about doing this for extended run times, but didnt think that a 8s 5000mah would stress the esc. He also suggested I upgrade to 8mm bullets. Everywhere I've read, it says the 5.5mm bullets are good up to 200 amps. Ive got the Castle Link on its way so I can monitor everything after I run. Am i pushing the safety envelope running 8s 5000mah through 5.5mm bullets? I was going to run tomorrow, but now Im totally unsure. What would you change in this set up, if anything?

[iamandrew]

Hi there
Id agree with CC on this one.
its like $10 for for 8mm bullets for a few pairs, better that than a $200 ESC

[Rumdog]

With an x452 that motor will hardly pull any amps.

[Make-a-Wake]

I dont see a problem with the 5.5 bullets for a low-ish amp draw as Rumdog pointed out. It may pull in the neighborhood of 120-140 amps at best with that prop.

What I would take into consideration is what the Castle tech told you, they are not always right by any means but it makes sense. Too little amperage supply can cause ripple currents etc................ and tax the ESC. The hull is certainly big enough to hold four 4s packs, I would use 8s2p if they are in your budget.

[WhatRLaws4]

Ripple current is exactly what he mentioned. I couldnt remember what he called it over the phone. I will wait until I get my Castle Link so I can get a better idea of how efficient my set up really is. First change will be the 8mm bullets. Do most people run 4 packs for a higher mah and Ive simply overlooked it?

[Fluid]

With the larger 8S and 10S boats most do run 2P on a single motor. CC is right, the cheap Turnigy packs usually do not supply the "C" rating they claim and can cause ESC failure. I've seen this first hand more than once with "blazing" results. Low amp delivery means high ripple current which is a major cause of ESC failure. It's also why 'cap banks' have become so popular, although their utility is questionable on many applications as they are more useful to counteract long power wires than to make up for inadequate packs. You can log your setup and see the ripple current, it should never rise above 10% of pack voltage, and then only for a second. Nothing wrong with the 8mm bullets, although 5.5 or 6mm plugs will work.



.

[keithbradley]

910kv....8s...x452...You shouldn't have a problem running 1p on that. That's a very mild setup.

You may want to run a larger prop, higher RPM, or both...in which case the 2p thing could come into play.

[WhatRLaws4]

Atleast the Castle Link will provide some much needed info on this. Should be here tues or wed. Then I will take it out for a short run, download my results and post them up. So if I were to go to 10s...am I looking at 4 5s packs? or just get 2 with a higher C rating? I would like to prop up eventually. Seems like a X452 is small for this hull.

[RaceMechaniX]

Just another suggestion if you decide to run your set-up as is: make sure the connections are nice and tight. While 5.5mm bullets should be able to handle moderate currents, a loose or poor connection will cause havoc and lead to bad scenarios. Also, try to make sure your battery and motor wires are short as possible preferably no more than 6-8" total between battery and esc. Shorter is also better for the motor as well.

On the first test make it a short run i.e. 1 min and check the temps(esc, caps, motor, connectors, batts) and look at the data off the esc. This will give you a good indication if the set-up is safe.

Good luck.

TG

[WhatRLaws4]

Yup, first run will be about a minute long with a short full throttle burst. When I get new lipos, should I simply get a higher C rating? I just read about the Dinogy packs @performancerclipos.com, and they will get my business next. 5000mah @ 65C is 325, well within working limits of my 200amp set up. I just really dont want to use 4 lipo packs for each run.

[96XP]

Trying to learn more myself and came across this and wonder if someone could comment on it:

"I was in a good state of mind to try something new, especially if it meant saving some serious money and make large electric flight actually affordable (up to this point, I had been dishing out $250 beans for a single 6S 5000 mAh battery pack).
I could get the same spec Turnigy LiPo pack for $85.00 beans (now the price has dropped to about $60.00). So I ordered one up thinking what could I loose at that price... Well, the only mistake is I didn't order more. I have since ordered many more Turnigy packs and now the newer Turnigy Nano-Tech's (which are even better) for my electric birds and they are all working better than the FlightPower & ThunderPower packs I was using before."

Also this:
"I'm afraid to say it, but just because a pack says it is rated at 30C doesn't necessary mean it is in real world applications. Realistically, C ratings are somewhat meaningless because they are rarely verifiable."

source: http://www.rchelicopterfun.com/rc-lipo-batteries.html