caphead

I have been getting into 120 sized models lately and i have a question what, rx batteries should i be using with standard high torque servos like futabas 3010's. i would like to stick with either NiCD or NiMH.
what size and capacity do you all consider a standard minimum for this size plane with maybee 6 of the above mentioned servos? links to actual pre made packs will also be helpful.
Thanks so much
Cappy

jetmech05

With 6 volt your servos will be faster and stronger. Running digital servos will require more capacity....Go to your local hobby shop and see what a 6V 2400mAh battery will run you. but before you go search the web for RC batteries, see what is out there
Good Flyin

MinnFlyer

My Feedback: (4)

Another factor is the type of flying you do. 3-D flying might require a little more capacity do to the extreme nature of the servo movement.

For standard flying, you won't need much. A 4-cell pack in the 1200 - 1400Mah range should do fine. If you fly 3-D, you would probably want something like a 5-cell pack in the 2000 - 2400Mah range.

I really like NoBS battery packs:

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

Jetdesign

My Feedback: (8)

I've been happy with the Hydrimax batteries from Tower. They say they are for high-draw systems and they've proven so for me. I have 6 digital servos in my plane and had no problems with the 4.8v 2000mah. I decided to upgrade to 6 volts though, and went with a 2600mah lithium-ion for $22 and a regulator for $25. Lighter than a 4.8volt, more capacity and constant 6.1volt output all day long.

Anyway, I was flying pretty much all day on a 4.8v, 2000mah Hydrimax:
http://www3.towerhobbies.com/cgi-bin...?&I=LXNRH6&P=0
http://www3.towerhobbies.com/cgi-bin...?&I=LXNHS4&P=0

If weight is not an issue, or you need more weight for balancing, you can get the 4200 sub-c battery. They are good for super high draw systems, but really the AA packs should do you just fine.

caphead

great thanks for the suggestions
right now i have two planes that are in question, these two planes are scale planes so no 3d.

a great planes RV-4 90 arf with 6 futaba 3010's and one standard servo. this is a 2.4 fasst system.
and a great planes PT-17 Stearman 120 arf with 4 3010's also a fasst system.

i have a 4cell 1000 mah AA NiCD pack in the RV-4
and a 6 cell 1100 mah AA NiCD pack in the PT-17 Stearman

so i guess i should probably switch these out for the hydramax 2000 mah NiMH ?

-pkh-

My Feedback: (2)

If you are using high torque and/or digital servos, I'd recommend that you get a pack made up of A cells, not AA cells. They have a much larger max current draw than AAs.

I typically use 2000mAh+ packs made up of 4 or 5 A cells. I get them from http://www.cheapbatterypacks.com

vasek

My Feedback: (4)

Cappy, I also use the Hydrimax 2000 6V

but my interest is shifting towards enelop cells. from what i heard its like NiHMs but better

can anyone elaborate on the enelop?

Rodney

If you can stand the slight additional weight that NiCad's have when compared to NiMh for equivalent capacity, go with the NiCads. They will give you a lower internal impedance and will last twice as long (number of charge/discharge cycles) and will be more tolerant of minor abuse such as overcharge or accidental deep discharge due to forgetting to turn a switch off.

jbess

I hate coming across threads like this. Now I have to get a battery for my 120 spacewalker cause the old 4cell 1100mAh isn't sufficient for 5 3010 servos, Thanks Cappy!!![:@]

carrellh

Cappy, are you having problems with the existing packs? If no, I wouldn't try to solve a problem that may not exist. I'd fly the planes and monitor the packs to see how much is drawn out of them per flight before replacing them.

caphead

no never had a problem, was just asked by a fellow flyer what i was using and he seemed to think that it wasnt enough capacity, which in return got me thinking (or rather worrying )
full charge on my tester is @ 5.8 and after about a 8 minute flight it was dropped to 5.3. never had problem but he just got me thinking.

Jetdesign

My Feedback: (8)

I would take a look at how much charge you're putting back in the battery at the end of the day. If you have 1100mah and you're only replenishing 500, there may be no need. I just got a 2600mah battery and am only using 500mah, so totally didn't need all that extra capacity, though it's sure nice to have.

As I said I flew the P out of my plane with 6 digital servos on a Hydrimax 4.8 volt, 2000mah battery. I checked it with meters, etc. and it performed flawlessly (and still does, just now it's in my 'little' plane).

jbess

Oh, Good. I don.t need new batteries!!! Thanks Cappy!

caphead

um that pack you got is over 12 years old man.

caphead

another battery question.

now if i were to have multiple quality single AA cell 1.2v 2000mah NiMH batteries, would it be acceptable to use a 4cell battery holder instead of using pre-made packs as long as the holder is secure?
I would think so. is there any difference?

Jetdesign

My Feedback: (8)

If you know the holder, batteries, and connections can handle the vibrations then you are good to go. I think the batteries approved for plane use have some pretty beefy solder joints between the battery poles.

Gray Beard

My Feedback: (-1)

I use the Hydrimax 6volt 2400mah when ever I buy a new pack. No big difference in price so I go for them. As for making up your own RX pack with a holder?? I know guys that make up there own packs and solder the wires then shrink wrap the pack, I know guys that use tape instead of solder then shring wrap the packs. I would worry about the heat when soldering.
Couple of weeks ago I made up my own TX pack and used a battery holder and soldered on my leads to that. I used the 2000mah Sanyo Eneloop batteries. Man did I score good, the camera shop was going to be closing so I got them for 50% off!!! The last two 4 packs they had!! I got to test it out yesterday, I flew all day plus worked on engines in the pit for over 6 hours. Full charge was over 11 volts and after a day of use my radio was still showing 10.6 or 10.8? So far I'm happy with my holder and pack. Give it a try, all you stand to loose is a plane!!

caphead

cool thanks for the all the info guys.

To be safe I decided to go with the hydimax 4AA cell 2000mah NiMH, I just feel better now that ill have more capacity. I dont think ill need the extra cell.

RC_Fanatic

My Feedback: (1)

I have two of the Hydrimax 6V, 1400mAh packs, both fairly new. One measures as 1200mAh, the other just over 1030! A couple of other older NiMH I have still measure to spec.

Gray Beard

My Feedback: (-1)

Just an FYI, I have to cycle new nim packs about 4 times before they come up to full juice. That's my average to get them up to snuff. I keep reading you don't have to but I found this to be false information.

caphead

cool ill keep that in mind!

RC_Fanatic

My Feedback: (1)

Both Hydimax packs have been cycled 5 to 6 times. The other ones I have were up to spec after one full cycle.