wannabapilot

Hey guy's if my futaba servos are rated up to 6 volts and my life e battery is 6.6 volts is that enough of a difference that I should regulate my voltage to my servos
They are not digital

JohnB96041

You need to check the receiver for the voltage that it will accept.

speedracerntrixie

My Feedback: (29)

I am going to run the same setup in my newest airplane. I see no issue with it.

karolh

I asked the Futaba rep Bax a similar question some time ago and his answer was that the servos would handle the extra voltage without any problems. Since then I have been running my 2.4 Rx system with Futaba analog servos on 6.6 volts and so far I have encountered no problems.

Zeeb

My Feedback: (41)

There are LOTS of posts about using A123/LiFe batteries around various forums including this one, perhaps you should do some more research to assure yourself that it's okay to use those two cell battery packs on anything that's rated for a five cell NiCD/NiMH. There isn't any more voltage coming off one of those two cell A123/LiFe battery packs than there is a five cell NiCD/NiMH which typically come off the charger around 7.2 volts which oddly enough, is where two cell A123/LiFe packs come off the charger.

Bax on the Futaba support forum just this morning told a guy that he could not use A123's on three different Futaba servos as they were designed for five cell NiCD/NiMH batteries. He has said in the past that A123's were okay after maintaining for years that you could not use them on Futaba stuff. Now it seems he's gone back to the old position, who knows what his actual answer is?

http://www.rcuniverse.com/forum/futa...s-voltage.html

My answer is that LOTS of people use those packs on their Futaba servos without issues, other that a servo which is only rated for 4.8 volts (which packs come off the charger at 5.2 volts) there should not be an issue. I've got a bunch of new Sbus servos going into an Avanti S jet and it's got A123 battery packs as do all my other airplanes which still run on that "other" radio system....

speedracerntrixie

My Feedback: (29)

So you are running S bus servos on a brand X radio? I know they would function just fine but didn't you pay extra for the S bus feature that you are not now able to use?

Zeeb

My Feedback: (41)

No they'll be used with a Futaba 18MZ but not in the Sbus mode on this model. I bought Sbus capable servos should I decide down the road to try the system, I'm still a bit leery of the setup. The jet will get a PowerBox Royal SRS with the built in Igyro system and use two of the little R6303SB 3 to 18 channel Sbus rx's with that PE.

Donwebster

And you didn't use an ESC which can supple 5V voltage to the receiver??????????

Zeeb

My Feedback: (41)

An ESC????

Are you kidding? This is a turbine powered jet we're talking about not some ducted fan... lol

Zeeb

My Feedback: (41)

Yes, the confusion comes from the original move to 6 volt systems which were five cell NiCD/NiMH. There were not any LiPO batteries or LiFE/A123 or Li-Ion to speak of so they were just called 6 volt. A 6 volt NiCD/NiMH comes off the charger at 7.2 volts as you note and pretty quickly drops into the high 6 volt range say 6.8 volts or so and by the time they actully hit 6.0 volts on a loaded voltage check, the batteries are basically dead.

Now you have a bunch of servos showing up usually labeled "HV" or High Voltage which is generally considered to be capable of handling an unregulated two cell LiPO/Li-Ion battery. Those come off the chargers at 8.4 volts and are generally referred to by their nominal voltage of 7.4 volts. This, IMHO is even more confusing because a two cell LiPO/Li-Ion pack is pretty much dead at 3.7 volts per cell and if discharged below that you may have a fire with a LiPO and ruin either LiPO or Li-Ion if discharged completely.

dirtybird

My Feedback: (5)

Most receivers can handle much more than 6.6 volts. They have their own built in regulators. For instance XPS specs theirs to 23Volts.
The only reason to limit the voltage a servo can handle is the voltage rating of the IC or FETs if used. If you hook it up and it works you can expect it to not fail. If it cannot handle the extra voltage you will find that out right away.

BarracudaHockey

My Feedback: (11)

6v rated servos work fine with A123's or LiFe

They are rated for 5 cell packs.

Think of this....they also have a 4.8v rating, and we all know that 4 cell packs charge to 5.5v or so

rmh

In case nobody noticed --- the 6 volt servos -or 7.2 volt servos will gobble all the amperage they can -if you load em to max.
so - you will /can eat more power from source (battery)
I am replacing my servos which require less than 6 volts , in any models which are other than small foamies
I just re fitted a 5 pound pattern ARF which came with an ESC/BEC simply because I have lost faith in these BECs staying cool
New servos are HV made by Savox (Spektrum) and are fed by A123 pack
In watching voltage depression -while stirring sticks - I get typically 2 /10s volt drop as worst case ( 6.6 down to 6.4 on freshly charged 1100 ma A123 pack.) The models this size typically slurp up about 300 ma in 3-4 flights-so the pack is still running 6.5 volts unloaded (at idle)..
These particular servos ( HV4030 Spektrum) are the tightest -around center- I have ever seen- I got these based on the 5060 HV which we have in another 5 pound pattern model