Horn Dude

Built a speed plane that only uses 3 servos. 2 hitec hs-7985MG and a mini hs-85mg.

LiFe pack I have now is a spektrum 900mah that I got from chief aircraft. I started to get brownouts only a few flights in. Pack charged after each flight. Uses 250mah per flight. Been going over whole electrical system.

But I want a true A123 battery pack. Been looking at radical rc and hangtimes.com

I see that there is an option to have 2 leads from battery to go to rx. Is this really needed or help at all? Or should a single lead be plenty for 3 servos.

Thanks

Truckracer

My Feedback: (19)

A single large Deans connector is fairly common these days. From there a HD switch with (2) power leads into the receiver should serve your power demands very well. The new JR electronic switch looks very good at under $30 but there are many other mechanical and electronic switches available.

cyclops2

Have you..... DESIGNED....... the propeller....motor...ESC.....receiver low voltage.....to run for a definite time ?

Your answer is no. Until you are able to do the design part of modeling anything, you will be upset by the results you are getting.

Lots of us went thru what you are going thru. Building / modifying models means you understand ALMOST everything about electricity. Stresses of mechanical parts. Weight reducing the rear of a planes parts. How to shift weights to get a level flight..............There are a lot of different areas of a plane to master to a average degree.

Most difficult in our hobby ? Figuring out which parts WILL....do what they say they will do. Modifying is fun. If you have a person to work with you to stop wasting money.

Post the prop, motor, gearbox if used, ESC, Plane maker & model. Weight of plane. Area of the wing. Incidence angles compared to prop shaft. how long you expect it to fly at WOT. Part throttle.

AA5BY

Two leads are helpful when two switches are used for flight control or when a gas ignition is also supplied from a single battery. Sometimes, even three leads are used.

Your question however raises a side issue. You should not be suffering voltage brown outs with a LiFe battery consuming 250mah unless the flight is quite short. I'd be interested in why you think brownouts are happening?

Truckracer

My Feedback: (19)

That could depend on the "C" rating of that 900 mah battery. If it has a low "C" rating, just those few relatively high torque servos could cause a brown out. I have had poor luck with the low capacity, low "C" rating LiFe poly style batteries especially compared to their larger brothers that are almost bulletproof. The 1100 mah A123 batteries were also great smaller batteries but I believe these are no longer available.

Horn Dude

Cyclops.. This is not an electric plane. Its a Diamond Dust. Jett .40 engine. Battery only powers RX and 3 servos for controls. Did initial range check. And 1st flight was just fine. Though I did not fly WOT whole flight. On second flight the next day, I was full throttle and pulled up elevator and plane rolled on me and I lost control for a bit. Killed throttle on TX and held right elevon and regained control after a second. Then I just landed in the field. Maybe speed dive and up elevator caused spike in amperage needed. Just pulled up C rating. 20C. Is that low for an RX pack? / a LiFe pack? Limited space so not sure how much higher of mah I can go for a higher C rating.
Since I recharge after every flight, and pop hatch to make sure everything is secure, I am going to eliminate the switch and plug batt directly into Rx.

Indiomike

My Feedback: (5)

Get the two lead battery from Radical. The second lead is there if you ever need it and if not, just tuck it out of the way.

Mike