BEC or not

[Palmboom]

Hi all,

Right now I'm building the Trex 800E pro dfc. My build is at the point where I want to put all the electronics in the heli.

I'm using all the Align electronics that came with the kit and a Futaba R7008SB receiver. I was wondering if it's still recommended/needed to use a BEC when applying a 2cell lipo for the electronics.

From what I understand some of you just plug in a 2cell lipo into your receiver and connect it with a s-bus connection to your Align 3gX. What do you guys advise me?

Sander

[JohnTC02]

Both of my 800 heli's and my 700 Pro are using a 2s lipo for running the electrics, they have all had hundreds of flights with zero issues.

A lot of folks here use a BEC even on HV builds with zero issues as well, it's down to personal preference at the end of the day.

The BEC vs 2s lipo debate has been thrashed out on these forums (and the 700 forums) many times so have a look at the older threads.

Can't really advise you on the s-bus connection as I use vbars, never had anything to do with s-bus.

[Bonkievan]

2s lipo here. Never had an issue.
I have just put the Optipower Ultra Guard on though. Nifty wee backup device, that works with either rx batt or bec, that is well worth a look whichever route you take, imo.

Btw, that led is not like the photo....its very, very bright. Unlike the Ultra Guard, most of these other backups/buffers don't let you know if there is an issue until you either land and check batteries or crash.
Telemetry helps but either way, all these backups/buffers are a good idea

[al93535]

I do believe you want to power the FBL and have power run via the s bus cable to your reciever. S-bus is awesome!

sent from a non Apple device

[Palmboom]

Thanks guys! i'm thinking of running the electronics without BEC

[pazza]

Don't waste your time with a bec on HV. Just another thing that can get hot and burn out..

[utrinque]

I got three 20A YEP SBECs for $8 each using rcsearch.info buddy codes. On 800s I use 2S lipos but Benji is using it in 800 and it works fine at 1600-1800 RPM with RJX HV servos.. I use it in Gartt 700 and works like a charm.

Probably I'll put one on one 800.

[Heli biggie]

2s lipo here also. I also have this in line so i can run a backup lipo, I havnt done it yet though. But there is plenty of room on this massive machine. I can get about 6 flights before I swap pack. Just to be safe I don't go under 3.83 a cell.
http://www.western-robotics.com/battery_buffer_hp.html

[1340]

Deleted.

[Ah Clem]

Just finishing a Velos 880 with a Western Robotics Super Pro BEC. Set it for 7.4 volts for use with my JR Wide Voltage Servos. 16 amps constant with 22 amps peak, available. Bus technology so there is no bottleneck with one or two five amp, servo type connectors.

I don't have to worry about running and maintaining a separate battery, or a battery backup system (with its own separate battery to maintain).

I already have three 700 size machines using these, with no issues, for several years.

[Dawiev]

Originally Posted by Bonkievan

2s lipo here. Never had an issue.
I have just put the Optipower Ultra Guard on though.

Hi, I use the Ultraguard on systems powered by BECs, but not with an RX battery. As I understand the UG to work, it senses the power level and then activates if power drops more than 0.5V below the initialization value ?

If this is correct, what happens when the RX battery power drops during flight & more than 0.5V ?

[K2Freak]

Good question. I've never heard of anyone using an UG with rx pack, although I'm sure it has been done. Might check the Optipower forum.

There is a good chance that you would see .5v or greater drop during the front end of the 2S charge. After one flight, or a little load, it should stabilize and the UG would reset it's "working voltage" every subsequent flight, but again, I have never heard about this.

Gryphon BEC and UG on all my big birds. I have lost aircraft to receiver pack failure - never again!

[Ah Clem]

Been flying this:




With this:



No problem!

[MS60]

That is impressive!

[chipfuad]

Originally Posted by MS60

That is impressive!

What a piece of machine!

Isn't more practicall to run a bec to the main packs? That way you'll get full voltage on every flight!
I know thats one more thing that can fail but you dont have to worry about another battery before any flight.

I run a gryphoon bec to one 6s pack and it's rock solid.

Regards.

[Ah Clem]

"Isn't more practicall to run a bec to the main packs? That way you'll get full voltage on every flight!
I know thats one more thing that can fail but you dont have to worry about another battery before any flight.

I run a gryphoon bec to one 6s pack and it's rock solid."

That is exactly what I do with the WR BEC's. I run them from one of the two main, 6S packs (in this case, one of the four main 6S packs).

You can have up to three cells in the main pack running the BEC, lose capacity or short out, and still have enough power through the BEC to operate the radio. With one 2S pack, lose one cell and you are done.

[chipfuad]

Originally Posted by Ah Clem

"

That is exactly what I do with the WR BEC's. I run them from one of the two main, 6S packs (in this case, one of the four main 6S packs).

You can have up to three cells in the main pack running the BEC, lose capacity or short out, and still have enough power through the BEC to operate the radio. With one 2S pack, lose one cell and you are done.

Can't agree more with you! That's exact how i think a setup should be.

Congrats on that piece of engineering. I'd love to see one in person.

Regards.

[Island Heli]

Loose a cell in your TX and the same result...All a gamble.....

[Nitrofever3d]

2s no problems so far.

[Bigdog714]

I do the same thing.....CC BEC Pro powered by the Mains. I used to fly a RX pack but always 3S so I didnt get a voltage drop.....i Could go 6 - 8 flights on a 1200 -1500 mah pack.

The bigger helis like my Logo 600SE just doesnt have room for another pack, and I can hang a BEC just about anywhere....put it out in the wind....its happy out there