One battery or two?

[Orcoz]

Guys -
I've been more successful than I had ever imagined with my first FPV effort. I've just added a Rembizi OSD, but my Bixler now has waaaay too much stuff up front, causing it to be a little nose heavy and flying fast.

So far I've been using two separate batteries. One main flight pack battery (either a 2200mah or 1300mah 11.1v depending on my mood) going to the esc, and then a smaller 450mah 7.4v battery powering the Camera/Vtx.

So my question - how should I go about eliminating the smaller battery? I'm not afraid of soldering, just want to know if I've got to purchase anything special to take the 11.1v down to 7.4v.

Thanks in advance!
Oz

 

[colorex]

What camera and Tx do you have? That is essential to know.

HobbyKing states that their systems can take 12v, but you'll probably run a bit hot on that.

 

[Orcoz]

It's a low end "Best offer buy" 1.2ghz system.

Here are the components that I put together:
ARF Bixler from Hobby King
3 cell 11.1v 2200mah zippy lipo from Hobbyking
Hitec 555 receiver
Hitec Flash 5x radio
various components in the Bixler build already mentioned in this thread
BestOfferBuy video TX/RX http://www.bestofferbuy.com/av-wirel...aign=affiliate
Sony Camera http://www.ebay.com/itm/540TVL-SONY-...-/260504715885
Hyperion 25c 450mah 3 cell 11.1v battery for onboard FPV gear
Hyperion 25c 450mah 3 cell 11.1v battery for video reciever
Tx and Rx CP antenna from Video Aerial Systems LLC (IBCrazy) in 1280 http://videoaerialsystems.com/produc...p-antenna-set/
7" Haier TV
1/4" sheet of depron foam board to build pod to hold airborne fpv gear, and later to build shadow box for monitoring video screen (haeir)
IBCrazy clover pair for rx/tx

 

[Orcoz]

When looking up my gear, I noticed that I am actually using 11.1 for both my plane and video... so I'm guessing I could do with just a simple Y harness. Is that accurate?

 

[colorex]

You can. But after a few searches on Google:

4. A separate battery to run the video equipment inside the aircraft is highly recommended. Using the aircraft's battery can make for poor video and if the battery runs out you will lose your video feed (Video Drop Out) making it impossible to see where the aircraft might land/crash. Try to keep all your wireless video equipment using the same voltage like all 5volts or all 12volts, most companies have both. 12 volt systems make the most sense because a 3s 11.1 volt lipo can power these systems without having to use a voltage regulator like 5 volt systems need. It's not recommended to power 5 volt wireless gear with the radio RX power source even though they have the same voltage. Doing this may cause glitching and/or shorter radio range.

Source: http://fpvpilot.com/GettingStarted.aspx

Here's an article explaining your question: http://www.fpvuk.org/things-explained/separate-lipos/

If you don't want to read all that, I'll put it in a few words.

Two batteries makes for cleaner voltage source, more weight and two things that can go wrong.

One battery will add noise to the power source, it will be lighter, and there's only one thing to check.

I'd stay with two batteries if that works, but I wouldn't be afraid to try it with only one as long as they run off 11.1 volts.

 

[bicyclemonkey]

single battery config.

 

[Burg]

Thansk BCM .. that config is what I have been looking for.
This will work fine on multirotors where you don't fly that far away and have limited frame-space.

About that second lipo for FPV gear battery + remzibi, what 3cell would you recommend (mah) ??
Should 370mah be enough for several flights ?
I want to keep it as light as possible..
Mark.

 

[bicyclemonkey]

I know Tim over at www.readymaderc.com includes 460mah batteries with his FPV systems. 370mah might be kind of low.

 

[Avi8tor]

A simple LC filter can help clean up the single battery esc noise. RC Groups has a considerable posting on using a ferrite ring that you wrap your positive lead around 8 or 10 wraps followed by a 25V 470 to 1000uf capacitor soldered across the positive and negative leads.

Works great and lightens up the front of the plane by getting rid of that extra battery.

Here is the link: http://www.rcgroups.com/forums/showthread.php?t=1339007

R/Avi