Question on battery capacity & weight.

[Flip465]

Question :- What size (mHa & weight) could be used in an E-Smart ?
NOT the flight pack - the other one that powers your Rx, servos, gyro, etc.

At the moment I'm using a 7.4V 1900mHa 12C LiPo pack and am thinking of swapping in one with a somewhat
larger capacity.
Don't think the little bit of extra weight will make that much difference - 85g. up to 190g. (Maximum)

Existing battery feeds through an Align 6Amp. External BEC to the Rx-JR RD921 2.4g & one JR EA101 sat. unit.
From the Rx this feeds 3 X HiTec HS-5965MG Digital servos on cyclic and also going through a 5.1V step-down
that feeds the gyro - a JR G770T unit with a JR DS8900G servo going to the tail.

Stock Esky E-Smart motor and gearing which works very well - no lack of power when its flying.

Thinking of going up to something like a 7.4V LiPo of about 4000mAh. Looking to get more flights in before having
to stop and re-charge this pack.
There shouldn't be any C of G problems with a slightly heavier pack - it will be going down where the main flight
packs normally go. Replaced the original Rx sole plate with a battery sole plate putting the flight pack up level
with the motor. :-)

Since I don't / can't fly anything like 3D - maybe its all the digital servos draining a bit more juice from the pack than
standard servos - whatever, I'd like it better getting more flights before needing to stop and re-charge it.

Flight packs are easy enough to change after each flight but this other one is fixed inside the frame with cable ties.

One last thing, the battery now used is rated at 12C without any heating or other problems while its working -
Whats the opinion of a 10C rated pack ? Will it be able handle the same output without problems ?

Ideas ? Thoughts ? Opinions ?

[Donnie D]

I'm in the process of building an all metal ES 600. I'm certainly no expert, but I'm planning to use 5 cell, 18.5v avout 4000 mAh batteries in mine. Hope that helps you. This battery will power everything using a BEC on my ESC.

Donnie D

[Flip465]

Originally Posted by Donnie D

I'm in the process of building an all metal ES 600. I'm certainly no expert, but I'm planning to use 5 cell, 18.5v avout 4000 mAh batteries in mine. Hope that helps you. This battery will power everything using a BEC on my ESC.

Donnie D

Hi Donnie,

thanks for your thoughts :-) I've got the metal framed ES600 as well.
From the start, decided to keep the motor and 'control' power supplies separate. Didn't want to risk any loss of control caused by the motor draining too much power from it's one and only battery pack.
Motor power comes from two 11.1V. 5000mAh batteries hooked up together to give 22.2V. 5000mAh feeding the motor through an Align 100A ESC. Everything else is fed by the 7.4V battery pack.
With the stock motor and gearing, this set-up has proved there is no lack of power from the ES600 - 5000mAh battery packs give a quite reasonable flight time as well. :-)
Bloody thing can, and will, strip the teeth off its main gear without thinking twice ! Hence the lack of E-Smart main gears at the moment. ;-(

So far its worked without any problems at all, no 'brown outs' from the Rx. When the flight pack starts to run low, each flight, the motor just slowly starts to spin down nice and slowly allowing plenty of time to set up for a landing- the radio link remains nice and solid. A new JR DSX9 2.4g radio might just be helping a lot too - it works GREAT ! :-)

So far, its had all the usual CNC metal up-grades fitted, main head gear, tail gear box, all the angel gear, etc. as well as the landing gear from a Raptor 90. (Esky gear is too soft IMHO)

After this battery change over, if it proves practical, then there's a G10 frame to think about. :-)
At the moment its got 95mm C/F tail blades fitted. There is also a couple of pairs of 550mm woodies to use yet, as well as a pair of SWE 530D FRP Main Blades to try out.

Good luck with your ES600, - enjoy yourself. :-)

Flip.
Perth.
Western Australia.

[acam37]

I use a standard JR 4.8v 600Mah flight pack battery to power my servos, gyro, and RX. I have no problems at all with flight times. It will last all day at the field without recharging. I just put it on the charger the night before and check the voltage before I fly. It sits directly under the main rotor shaft held in with velcro.

[Donnie D]

Just ordered my ESC, program card, BEC, deans connectors, and a wire extention today. Now I need my gyro, Batterys and a charger that will handle 5 and 6 cell batts. Then I can put it all together, set it up and hopefully start flying. Can't wait.

Donnie D

[nasukaren]

My BEC runs off a Zippy 1300 mAh 2S1P 20-30C lipo. Works great, runs forever.

k

[damyxz]

I have been using a 2S 1300mAH receiver pack. I have tried the bigger 3000 mAH pack. I ended up losing about a minute of flight time because of the extra weight. It also made my heli sluggish during maneuvers.
I gave away the 3000mAH and went back to the 1300's.

[Donnie D]

OK Karen, this is gonna sound real dumb. You said your BEC runs off a 1300 mAh lipo 2 cell. I'm not sure what you mean by that.
I haven't finished my ES600 yet, so I haven't hooked up any electronics, but the way I planned to hook up my ESC is:

BEC red and white batt leads soldered to Deans conn along with ESC batt leads, and that plugs into main battery-- BEC plugged into rec batt slot--ESC plugged into rec throttle slot--and of course ESC plugs to motor.

Why do you need a seperate 2 cell lipo?

Donnie D

[thunderhead]

Hi guys and girls. I'm running a 7.4 1800mah lipo to my BEC. This batt. runs Hitec 6965 digitals on cyclic all day long. I have it mounted in the rear of the frame with my 85HV strapped on top just behind the main shaft. I get about 8 mins on 4500mah 30c 22.2V lipo. Granted not 3D flight but I,m tearing around pretty good. Mostly loops, rolls, piros and some inverterted. I,m an old planker at heart and my flying is more pattern style manouvers. Good to see some activity on the E Smart forum.

[nasukaren]

I was running a separate BEC battery so that in case I ran the main battery down (or something happened to it), I'd have a separate electric system. Kind of like what youd do for nitros. And it was easier to find a high-amp BEC that ran on 2S than one that ran on 6s....

Oh well.

K

[Kevo450]

Originally Posted by nasukaren

I was running a separate BEC battery so that in case I ran the main battery down (or something happened to it), I'd have a separate electric system. Kind of like what youd do for nitros. And it was easier to find a high-amp BEC that ran on 2S than one that ran on 6s....

Oh well.

K

This is confusing to me.

My first though was why would you even use a bec in this setup ( your not elimatining any batterys :-)) , but then I noticed your using a 2s lipo ( which causes even more questions for me ) So I guess the bec is simply acting as a voltage limiter in this setup.

Why are you using a lipo and not a ni-hm or nicad 'reciver pack'. Is there some advantage to using a lipo in this situation ? wouldnt a ni-mh or even a ni-cad pack be better suited to the lower current demands of the radio ?

Or am I not understanding something ??

[Tyree]

Karen is running two batteries one just for the motor and the other with the bec for everything else i.e. receiver, servos and gyro etc. The receiver, gyro and servos run on 4.8 - 6 volts so you are correct in thinking the bec drops the voltage to a usable level. One reason to do this is you can use a higher capacity battery to run the receiver etc. this will last longer without having to recharge it.
Some people just use regular receiver batteries like they got with their radios that are usually 4.8 volts so no bec is needed because the voltage is right already. These flight packs are usually pretty small so you have to bring several of them with you if you are going to fly all day. That's what Karen avoids by using her setup.
By the way, digital servos use quite a bit more current than non-digital servos.

Hope that helps,

Ty

[damyxz]

Running a separate flight pack is a good thing for helis this size, the main motor can overdraw power from the battery at times and will not supply the receiver and the servos, hence lost of control(deadstick). Let's say that you have a mishap that your ESC fried in flight, or your motor fried, the frying the ESC, with a separate pack, at least you still have cyclic control to do an autorotation and land the heli safely(this has saved me a lot of bucks a few times). I prefer a small 1300 mAH lipo because it is lighter than a same capacity nimh pack. Lighter is better in the sense that you require less energy in flying the helicopter, and there will be less wear and tear on your heli because there is less stress during flight. So there is no sense in putting a 4000mAH li-po pack if your heli can only fly an average of 5 min. I just have 3 separate small flight packs and just swap them over as my voltage indicator turns low.