4.8v or 6.0v?
 

I'm currently using a 4.8v 2100mah battery to power 5 S3152's on the control surfaces and a S3001 on the throttle.

Can anyone let me know if I can use a 6v 2100mah in order to improve the performance of the s3152's?. Is it as simple as just plugging in a different battery or do you have to change anything else?

Extract from Futaba website:

4.8V 69.0 oz-in. 0.22 sec/60°
6.0V 87.0 oz-in. 0.18 sec/60

Thanks

RE: 4.8v or 6.0v?
 

You can change them out all you ahve to do is switch the battery

*BUT*

know that a 2100mah 6 volt wont last as long as a 2100mah 4.8 volt so you may want to boost it a bit.

Steven

RE: 4.8v or 6.0v?
 

Also keep in mind that some receivers and servos are not made to withstand the voltage of a 6v pack. Very few won't work with 6v but it's best to check.

Austin

RE: 4.8v or 6.0v?
 

Another important thing to keep in mind when using lots of digital servos is the high load they put on your battery. Cell impedance is just as important as Mah capacity. Might not be that critical on a sport plane but I like to be safe. Here is a section cut from NoBS Batteries site.

Q: What's the big deal about 'Impedance'? What is it and what does it do?

A: Most folks react to the 'capacity' rating alone as being the biggest part of their decision in selecting a pack for their big aggressive birds. This can lead to big trouble on board the aircraft. Just as cells are evaluated for capacity, in high load applications you need to take into consideration what the cells voltage performance will be when loads are applied. All battery technologies react to servo loads with a voltage drop while the load is applied. It's really very simple.. the higher the cells impedance rating, the greater the voltage drop will be while servo loads are applied. Rule of Thumb for cell selection: Impedance Ratings are like a Golf Score. The lower, the better. Aircraft in agressive aerobatic enviornments employing digital or high torque servos should carry a cell impedance score of 10 mOhms or less. As an example, one of the most popular lightweight packs used in IMAC aircraft is the Sanyo HR 2700AUX.. plenty of capacity, but the impedance rate on the cell is 20 mOhms. Pretty high.. but if it's used in parallel with another 2700 pack the impedance rate is cut in half to 10 mOhms (and the available capacity is doubled). This is why you usually see this pack employed in parallel in IMAC birds and used without issues as a single pack in a giant Cub.

More info is available at http://www.hangtimes.com/rcbattery_faq.html

RE: 4.8v or 6.0v?
 

Not to change the focus of the original question, but I think it follows along; how I understand it, this is what happens to those who are experiencing a "failsafe" or "brownout" or "lockout" condition on their 2.4 GHz systems. I would imagine that most people are using 4.8V packs, and even with a full-charge voltage, with the higher cutoff voltage that the 2.4 Rx (Spektrum for sure, don't know about FAAST) is reported to have, the voltage drops enough during some maneuvers that the Rx "quits" intermittently until the voltage rises again above the cutoff threshold. Of course, by then, you've walked out to pick up the pieces and what's left works fine again.

Would using a 6V pack, with sufficient capacity, such as paralleling packs, be a gaurantee against this occuring?

RE: 4.8v or 6.0v?
 

I guess I will be the stick in the mud and ask, because this is a beginners forum.
What airplane are you flying?
What is your experience level?
The reason I ask, again this is a beginners forum, most beginner and second planes would have plenty of authority with the servos you have. In fact at 4.8v you probably haven't flown the airplane to its max potential. Going to 6v shouldn't make any difference at all UNLESS you are flying something very aerobatic and with enough skill to be able to tell the difference in any servo torque/speed.
The answer to your question is yes it will improve performance of the servos but it will also reduce flight time on the battery pack.
PS: another thought. Those servos are 69oz at 4.8v more than enough for anything being flown by the majority of the people on this forum. More than I have in my 1/4 scale RV-4.
Are you flying Giant scale? I do have high torque servos in my Showtime 90.
.18 to.22 on the speed. are you going to be able to tell a 4/100th sec. difference?
All that said I am not against using a 6v pack. I just don't want you to get the wrong impression on what it will do for you.

RE: 4.8v or 6.0v?
 

6v packs only run about 5 or 6 percent shorter than an equivelent 4 cell pack.

RE: 4.8v or 6.0v?
 

Just as important as having low impedance batteries is to be sure and use heavy duty (large diameter wire) leads and switches. Do not use servo extensions, solder in longer leads if necessary, as the connectors themselves often provide a high impedance, especially after bing installed for a time and not disconnecte/reconnected occasionally as they do corrode, some more than others. Yes, digital servos and long leads can cause severe enough voltage dropouts (they only need to be a few microseconds of duration) can cause 2.4GHz systems to reboot. A 5 cell battery is no guarantee against this if the wiring and battery impedance is to large. Note the word IMPEDANCE which is the opposition to any sudden change in current, not just resistance and this can have a significant effect when high currents are pulsed like happens with digital servos.

RE: 4.8v or 6.0v?
 

This is well beyond what a general beginner would encounter. For the most part, many are just trying to learn to successfully fly what they bought let alone trying to figure out if the internal impedance of their batteries is sufficiently low.

Needless to say, the original question was geared toward if the user could/should use a 6 volt pack vs. a 4.8 volt pack in the same amperage rating. The answer to that question is somewhat of a qualified YES. The 6 volt pack with the same mah rating as the 4.8 volt pack will not last quite as long, but it will work with most receivers. It is best to check with the manufacturer of the receiver to see it it will work with the 6 volt pack. If so, then, with the qualification noted above, it will work. If the manufacturer states 4.8v only, then it behooves the user to stick with 4.8 volt packs.

CGr.