RCBOZO

My Feedback: (1)

Brand new GWS 350 w/ D gearing. Brand New GWS 480 ESC (15 amp) fairly new Li-poly 3cell 1020Mah GWS 12 x 8 prop. Fresh charge on the battery. All in a Slow Stick. Taker it up at 1/4 throttle hand launch. Fly it around for about a minute at no more than 1/2 throttle. It died like the battery gave out. Put the battery on my Triton set up for another charge 1.1 Amp @ 11.1 volt and the triton shows the pack at 12.1 volt when it starts up, before it even put any juice to it!

I was having similar problems before with the stock GWS 300 and the GWS 100 ESC ( 5 amp) but I could get about thirty seconds of full power and then about 4 minutes of 1/2 throttle before the Li-Po died.

I really though that the new motor and ESC would solve my problems with the cut out but it seems worse!

Matt Kirsch

My Feedback: (21)

Your problem is the battery. The Kokam 1020 LiPoly can only put out about 3 Amps on a continuous basis, 5 Amps for short bursts of 10 seconds or less. The GWS EPS350C with 12x8 prop will draw 7 Amps at full throtte on a 2S LiPoly, and over 10 Amps from a 3S LiPoly. You're simply trying to draw more Amps from the battery than it can produce. LiPoly batteries come with VERY specific limitations on current that you MUST not exceed.

Switching to the EPS350C made things worse. The EPS350C is more powerful than the EPS300C because it draws more Amps. The battery couldn't produce enough Amps to run the EPS300. There's no way it can produce enough Amps to run the EPS350C!

You need to have a rough idea of how many Amps your power system is going to draw, and you need to pay attention to the capabilities of any LiPoly batteries you're considering. LiPoly batteries will have discharge capabilities listed in terms of "C." C is the mAh capacity of the battery converted to Amps (divide by 1000). The Kokam 1020 is a "3C" battery, meaning it can produce 3 times its capacity in current on a continuous basis, or about 3 Amps.

I'll be surprised if your battery isn't ruined... Sorry

RCBOZO

My Feedback: (1)

So I am looking for a 10 - 12 C battery to keep up with this motor? I'm not sure I have seen anyone who carries those I have seen 6 - 8C but not much more.

jonnyjetprop

My Feedback: (3)

Kolkam 1500 is good for 12 amp continuous and 15 amps surge. (that's 15-20 sec.)

Etec 1200 good to 7.2 amps

Hope this helps.

John Pursell

RCBOZO

My Feedback: (1)

Kokam 1500 is a 8C battery am I right in thinking that it will only give me 8 amps?

Dr Kiwi

No, 8C is "eight times the capacity", so for those particular Kokams, 8 x 1500mA = 12A. QED!

The only batteries available at the moment which can give you more than ~8C are the 340SHC Kokams which are rated at 20C (though some recent testing suggests that is very extravagant). Tanics are said to be able to produce 8-10C, but that may have a bit of hype in it too.

If your plane can carry a bit more weight the easiest thing to do is to parallel a couple of packs - 2s2p 2400 E-tec would give you 14.4A potential.

Cheers, Phil

Dr Kiwi

Sorry, I didn't realise you were running 3s - well then, 3s2p 2400 E-tec!

I'd go smaller with your prop on 3s though - those GWS motors may be good for 70-80W or so, but they won't last long at all if you push 11.1v x 10A = 110W through them!

You are lucky you had lousy batteries with your original 300 set up and the 5A ESC - if you had had batteries capable of supplying that motor's needs, you would almost certainly have fried the ESC!

Cheers, Phil

RCBOZO

My Feedback: (1)

Dr Kiwi
I got a new pack, E-Tec 2S2P 2400 Mah. I was told that this battery would sustain 15 amps. I tried it today and I did not have any better luck. I never got above half throttle and it still cut out after a minute of throttle time. I need some help because I am greatly dishearted with Lithiums right now.

Matt Kirsch

My Feedback: (21)

By all rights and means, that setup should work fine. It should draw no more than 8-9 Amps at full throttle. I run a single Etec 1200 pack (2S1P) on an EPS300C drive, C gearing, with a 9x7 3-blade, and have no problems.

If your ESC is still cutting out, then you have a serious problem. GWS ESCs have a low-voltage cutoff point of around 4.5 Volts, which is way lower than you should ever draw any 2-cells-in-series (2S) LiPoly pack, no matter how many you have in parallel.

Are you soldering your own connections? You'd have to be, because the GWS 480 ESCs doesn't come with plug-n-play connections like the smaller ESCs do. Bad soldering leads to high-resistance connections. What type of connectors are you using? Do your solder joints look smooth and shiny or chunky and grey?

RCBOZO

My Feedback: (1)

I am not sodering. I am twisting the wires and shrink wraping them.

RCBOZO

My Feedback: (1)

I also am using the little red ? JST connection.

john 8750

You need to solder all joints and use a better connector. The Jst is for smaller currents. And the unsoldered joints are a big part of your problem.
Take care of that and let us know what happens.[8D]

Boss248

RCBOZO...Please solder the joints and use better connectors than the JST. You have some expensive equipement and wanting to pull major amps and then you twist the wires together and wonder where all your current is going.