digital servo & battery
 

maybe someone could help me with this i have put in four futaba s9252 digital servos and one s3004 . someone said that the digital stuff eats your battery up fast . was trying to stay lite so i had a nr-4j 600mah and was going to use how long would this run and should i go bigger like a 1500mah thanks for any help and is there a fomula to figure out the how long a battery will run a said amount of servos?

RE: digital servo & battery
 

You definately need the 1500mah pack. At peak amp draw, your 600mah will not take it. I do not have digital servos on my plane. However, in my heli, I have 3x hitec 6965, one futaba 9254 and a futaba 3001(quite similar to you, 4x digital and 1x normal) and it draws about 200-250mah in a ten minute flight.

RE: digital servo & battery
 

Maybe I am on the wrong page, but why can't you keep the weight down and use the small battery and charge the plane between flights. It only takes about 3 to 5 minutes to charge with a quick charger.

RE: digital servo & battery
 

I'm running some standard Futaba rx packs with 4 digital and 1 standard servos. Get about 3 or 4 flights before throwing them on the charger.

RE: digital servo & battery
 

thanks i came up with a 1450mah Nimh that has about the same weight as the 600 . and fixed it were i can change out easy just to make sure i also put a volt watch . will the volt watch drain the power ?

RE: digital servo & battery
 

Yeah, but not enough to lose any flight time.

RE: digital servo & battery
 

Yes, you can, but it would be advisable to start praying that nothing binds in flight and you don't bang the stick too fast at the end of the flight. At peak amp draw, the digitals will suck lots of amp and pull the voltage really low.
Try this: get 4 digitals and one normal servos and run it on a 600mah pack that is 75% charged with a voltage tester, you will see how fast the voltage drop when you pull all the servos at one go. And that amp draw is only for no load, imagine you are up there flipping and flopping, the load on the servo will get a lot greater.

RE: digital servo & battery
 

should i maybe use some standard stuff in the wings and cut it back ? when seting up the plane lastnight i watched the power drop fast with all four maybe one flight worth of time to be safe out of the 600mah .

RE: digital servo & battery
 

what plane are you using the servo on? IMHO, you don't normally feel a big difference in centering between a good analog servo and a digital unless your linkage rod are extremely stiff and your linkage is 100% slop free. And with regards to the torque thing, if you really need the torque and don't want to run the big battery pack, the 635hb or the 645mg is a good choice.

If you can afford it, go the lipo way.

RE: digital servo & battery
 

its in a v2 kantana pulled it all out of my smashed funtana40 i know that it is over kill for this plane how much are these batteries not that worried about the money as you can see i put a few bucks in the four servos. more torque than needed i was looking at a 2100mah lipo there not that bad. can you tell me more about the other bats. you were talking about thanks edit to say i have no slop at this time and stiff rods changed out most of the hardware that came with this arf .

RE: digital servo & battery
 

just thinking again but a lipo is not the correct voltage inless im missing something

RE: digital servo & battery
 

You can use lipo for a battery but, you would need to use a regulator from companys like duralite and MPI to name a few; to drop the voltage down to 6V or lower. But the cost of the setup plus the reg wont be justifiable for something of that size. Plus its another point of failure your adding to your plane. Im using a JR 1500 pack and im getting about 4-5 flights with hitec 4 hs5625 and 1 5645 servo. Works by me.

RE: digital servo & battery
 

ok thanks rcfury but i dont want the battery you had in that plane in you avatar think i will use some other servos in the wing and run the 1450 mah . i have a spare to change with and watch the volt watch.

RE: digital servo & battery
 

just kidding about the pic . i have a few of those my self and more to come .

RE: digital servo & battery
 

I have been buying 2100 NiMH 6V AA packs from Maxx Products for about $25. They weigh the same as your NiCads and the 1250, 1450 and 1650 NiMH. Here's there web page http://www.maxxprod.com/mpi/mpi-7b.html

You can quick charge between flights, but I get more than 5-6 flights on a pair of them in my 35% Extra, also use them in my other smaller planes, because they don't weigh much, last a long time and quick charge on my Sirius charger in nothing flat.

Hope this helps.

RE: digital servo & battery
 

http://www.hangtimes.com/sportrxpacks.html

GP 1100ma 4.8v NiMH 4 cell Mini Ignition and Reciever pack. Ideal for systems needing very high capacity while remaining smaller and lighter than any standard AA OEM dimensioned pack. Super small, Super high capacity, very low internal impedance. Same dimensions as the Sanyo 500A nicad with TWICE the capacity with half the impedance of a AA pack. This is an outstanding choice for a lightweight ignition pack with the punch to handle the loads. Also an excellent choice as a Rx pack for .40-.60 sized aircraft with high torque servos. High-Rate NiMH engineering designed to deal with high current loads without the typical voltage drop common to AA sized cells.

Single cell dimension: .67 x 1.1
Finished pack weight, inc connector: 3.3oz $23.95
Internal Impedance: 7 mOhms

RE: digital servo & battery
 

I fully agree that the GP1100 cells are a great choice.

I get my packs from Radical RC and they charge $16 for a 4-cell pack or $19.50 for a 5-cell pack (with your choice of Futaba or JR/Hitec plugs). Note that on the Radical RC site they're actually listed as 1050mAH packs but they ship 1100mAH with the GP cells.

I've been using these packs in all my 3D ships (with HS5925 digital servos) and they give me an easy 5 flights (8-10 minutes each) between top-up charges. They not only have a very low internal resistance but will happily take a 2C charge rate so topping them up takes just 15-20 minutes.

RE: digital servo & battery
 

I have been running a [link=http://www.fromeco.org/]FROMECO[/link] 2400 LiIon 7.4V pack ($27.50) with a FROMECO Super ReliaSwitch Voltage Regulator and Failsafe Pin/Flag switch ($47.50) on a GP Patty Wagstaff. I run 4 ea. Hitecs HS-5945MG's that draw 3mA/idle and 180mA no load, and 1 each HS-5995TG that draw 300mA/idle and 4.2 amps at lock/stall. I usually get eight to ten flights with planty power left at the end of the day.

RE: digital servo & battery
 

You are on the right track. I have a 2500 ma 4.8 pack (AA) size by JR. I replaced a 500 MA pack with it and I fly two or three outings and the pack is still way up. I only use standard servos, but the point is the new higher ma packs are the only way to go...not near as much fooling around recharging or wondering if you have enough for one more flight.

RE: digital servo & battery
 

Digital servos NEED current and a low mAh pack can not handle there high draw from small packs. They may only need 500-1000mAh total but have a NEED to be able to draw larger amounts of current than std servos do. I am going to be running a 1800mAh pack to run 4 5925 servos because it has the LOW IMPEDENCE I need and the size to last a few good flights.

Dave

RE: digital servo & battery
 

YES ............ i found a 2700mah NiMH 4.8 sanyo for 32.00 and there aint much diff. in the weght 4- cell with that and the 1450 i will just swap out .

RE: digital servo & battery
 

Your on the right track. I have that same plane. I power mine with a 1400 mAh Duralite Li-ion w/ regulator. If I had to do it over again I would just stick a 2000+ mAh Ni-MH in there. It may be a little heavier than the LI-IONs but you got to think about the weight of the regulator (1+ oz.). In the .40 sized stuff I would go with a 6 volt NI-MH b/c the weight will be the same at a lower cost.

RE: digital servo & battery
 

Why spend $32 bucks on 2700 NiMh when [link=http://www.fromeco.org/shop/shopdisplayproducts.asp?id=11&cat=2400+mAh+Lithium +Ion+battery]FROMECOS LiIon[/link] 7.4V 2400 mAh packs sell for $27 ? The Super Relaiswitch regulator is $47 but it includes the failsafe Pin/Flag switch, and it's fully adjustable from 5.5V to 7.2V. A good failsafe switch will cost you arround $30, and a fixed output regulator with failsafe switch will cost you about $39 ([link=http://www.maxxprod.com/mpi/mpi-28.html#Miracle%20Switch]See Mpi Miracle Switch[/link]).

If you REALLY want to have Failsafe/Redundancy, for another $30 a [link=http://www.smart-fly.com/Products/BatShare/batshare.htm]Smart-Fly BatShare [/link] will let you hook up two (2) 2400 mAh LiIon batteries for a total capacity of 4800 mAh :D

I know that's a lot more money a lot of folks are willing to expend for power insurance on their 25% or smaller planes. But it sure buys you alot of peace of mind on planes of 25% and better. When you spend $1500 or more on a plane, $123 in a bulletproof power supply system is a worthy investment.

RE: digital servo & battery
 

no juice left is no fun thats a fact been there done that ..dont want to be there again.. it makes a mess i got three flights on the 1450ma and was seeing yellow on the volt watch after landing i think that on the 2700ma i should get maybe five to six this thing is burnin up some fuel for now still a little rich so a tank is about 6-7 min. thats not much fly time on that 1450 but like i said before i made it easy to change out . thanks for all the input im learning from it . what is the best charger for the Nimh batery packs and will it do lipos to

RE: digital servo & battery
 

In my opinion the best bang for the dollar charger in the maket rigth now is the Great Planes [link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXCJG7&P=ML]Triton.[/link] It will handle 1-24 cell NiCd or NiMH, 1-4 Lithium Ion or Lithium Polymer cells (Li-Ion/LiPo) or 6, 12, and 24V lead-acid batteries. It sells for $129.99 but Tower will give you $20 Off with your order of $125.