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Old Nov 01, 2011, 03:15 AM
Falcon
United Arab Emirates, Dubai, Dubai
Joined Mar 2011
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Maximum voltage for Servos

I am using Spektrum A6010 servo on my 30CC plane. (Voltage rating for the servo is 4.8v or 6v.)
I know many people who are using 6.6v battery packs (Life/A123) on these servos without the regulator, however some says it's not safe and I should use the regulator to bring the voltage down to 6v?

Has any one used Life/A123 battery packs (6.6v) on these servos without using the voltage regulator?
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Old Nov 01, 2011, 06:59 AM
Registered User
Kansas City
Joined Apr 2010
652 Posts
I am at 100% LIFE batteries in my planes. No problems with any of the servos, which are mostly Hitec. My radio is Airtronics, so I can't say in regards to your radio. No servo jitters, just a lot faster than 4.8 volts.
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Old Nov 01, 2011, 07:00 AM
Registered User
Jacksonville Fla.
Joined Mar 2007
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Yes there are people that do it....I won't it says 6V....I know a fully charged battery is over 6V...But a LiFe battery stays above 6V for a while....which would you rather buy 1 voltage regulator or servos?
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Old Nov 01, 2011, 07:30 AM
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USA, TX, Grapevine
Joined Dec 2008
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I have seen some guys do it with some success. But it is very risky. Exceeding the max voltage rating on the servos could have them fail on you. So besides trashing servos you could trash the plane and other stuff then too.

I would suggest getting the high voltage rated servos intended for up to 7.2v LiPo cells. Then you have more peace of mind.
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Old Nov 01, 2011, 09:52 AM
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United States, NY, Syracuse
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NiMh packs seem to "overcharge" more than LiFe packs in my experience. While a 5 cell NiMh pack is rated at 6v, it tends to charge up closer to 7v... LiFe seem to be closer to their actual rating, maybe 6.7-6.8v.
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Old Nov 01, 2011, 03:27 PM
Falcon
United Arab Emirates, Dubai, Dubai
Joined Mar 2011
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Thanks guys for the valuable comments and sharing your experiences.
What i can conclude from this is not to take risk by putting the battery directly and rather use voltage regulator......
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Old Nov 02, 2011, 09:56 AM
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Northwest Indiana
Joined Feb 2011
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I use A123's without a regulator and have zero issues. If you use a regulator, you are just introducing another potential failure point. As was said above, all of my 6v NiMH's charge at or above 7V. There should be no issues at all.

Just my .02
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Old Nov 02, 2011, 10:23 AM
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Yeah, my comment was meant to be in favor of running LiFe without a regulator. As long as the servos are rated to 6V (manufacturers rate based on the nominal voltage of the cell, expecting that you will be using a fully charged 5 cell NiMh or NiCd) then it should work fine.

Running a 2S lipo would be a different story because the rated 7.4V would be upwards of 8.2V fully charged which is way too much and that is when you'd want a voltage regulator.
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Old Nov 02, 2011, 11:46 AM
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Northwest Indiana
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Quote:
Originally Posted by ChillPhatCat View Post
Yeah, my comment was meant to be in favor of running LiFe without a regulator. As long as the servos are rated to 6V (manufacturers rate based on the nominal voltage of the cell, expecting that you will be using a fully charged 5 cell NiMh or NiCd) then it should work fine.

Running a 2S lipo would be a different story because the rated 7.4V would be upwards of 8.2V fully charged which is way too much and that is when you'd want a voltage regulator.
Yep, exactly.
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Old Nov 02, 2011, 12:14 PM
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Morgan Hill, CA
Joined Sep 2007
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I'm not sure on the LiFe batteries, but I do use 2s lipo's on a couple of airplanes. The spec published for some of the Spektrum receivers says they are good up to 9.6 volts....they don't state that for the servos. Accordingly, I have used battery eliminator circuits (BEC's) on the airplanes and set the regulated voltage to 6.0v. The BEC is really just another name for a DC-DC converter, and yes...it is another item in the chain of things that all have to work if you want to maintain control. I have noticed that Hitec has some servos that are rated at higher voltages which would allow the use of a 2s lipo without any voltage regulation necessary.

Dan
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Old Nov 04, 2011, 06:45 AM
Will fly for food
Maryland
Joined Sep 2004
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"6 volts" doesn't mean 6.0 volts. And "4.8 volts" doesn't mean exactly 4.8 volts.

What they really mean are 4 and 5 cell NiCd or NiMH packs. Which are NOMINALLY 4.8 and 6 volts.

A 4 cell NiCd or NiMH pack right off the charger is almost 6 volts. And a 5 cell pack is around 7 volts.

In fact, when those packs get down to 4.8 or 6 volts, you should stop flying until you recharge.

A "4.8 volt" servo will run fine at 5.2 - 5.8 volts and a 6 volt servo will run off of 6.8 volts. And some "6 volt" servos will run off of 8.4 volts (fully chare 2S lipo), but they are not cheap micro servos.
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Old Nov 04, 2011, 01:07 PM
Falcon
United Arab Emirates, Dubai, Dubai
Joined Mar 2011
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Thanks guys.
I installed the Life (2S) battery directly to the RX without using voltage regulator.
My maiden flight for Aeroworks Edge 540 with the new DLE-30 was just superb.
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Old Nov 06, 2011, 05:39 AM
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Birmingham, Alabama
Joined Jun 2002
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a 4s nicd is 5.8v
a 5s nicd is 7.25v
good nicd cells should take 1.45v as a surface charge that drains quickly. tho only rare few chargers can do that well (old litco alpha can)

so yes. most 4.8v servos of any quality can use 6v (SIX VOLTS, not six and a lot of change...)


2s life is not a bad stretch for a lot of 4.8v servos to handle as long as the load is not heavy. 2s lipo, however, is. if its a servo that has a lot of load on it. bigger servo > reliability than over worked servo
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Old Nov 06, 2011, 07:46 AM
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United States, NY, Syracuse
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Just about every servo made in the last 10 years is rated to 6.0v. It's not often that we even need to discuss 4.8v servos.
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Old Nov 07, 2011, 11:50 AM
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Jacksonville Fla.
Joined Mar 2007
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there are retract servos that are still 4.8V only...if I remember the number correctly the Jr 751, or 752 is 4.8
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