landeck

My Feedback: (1)

John, I have 10 planes on Futaba 7C and 8FG 2.4 Fasst systems. Eight use 4.8 volt 1000 mha to 1400 mah batteries and two use 6 volt 1500 mah batteries. In 3 years of flying 2-3 times a week I have never had a problem. With the Futaba Fasst receivers, the servos will stop working before the receivers quit on a voltage drop.

Bruce

cloudancer03

My Feedback: (22)

man there is alot crazy info about battery size.why you would use a perfectly good hs 225mg in a 40 to 60 nitro plane is beyond me.as for spectrum I did experience sadly 2 brownouts ten minutes apart costing me two planes.I found out later a 6 dollar spectrum part plugged into an open channel likely would have averted that .needless to say I am back with futaba.I think its silly to argue over 4.8 vs 6.0v.I flew 4.8 without incident but always opted for alot of capacity.If you use old fashioned analogs on a std.servo with a regular 40 to 60 plane I see no reason why 4.8 wont do the job.I fly hard and typically use more and more digital servos and would use only 6v batteries.with respect to 2.4 systems I prefer 6v only because theres a question about voltage sensitivity and at 6v you give yourself a bit of redundancy.but in the end you need to manage your batteries well.it was my biggest weak spot in my earlier days and more planes were lost due to poor battery testing on my part.I make sure every session and during the day that my battery is safe to fly with!!regardlessof 4.8or 6v.until a few years ago I didnt know how to size a servo for a plane and I betcha theres alot that still dont.so you need to know your planes torque needs.

pdm52956

My Feedback: (1)

Back the the OP's question.............I've only been flying a couple years. I started with 4.8 in my trainer and upgraded everything to 6 volt. The trainer came that way so let's not go there. You asked "can you actually tell the difference". I for one can't but I don't fly extreme high alpha stuff. I like to put around and do an occasional loop or roll. I might even get real cocky and do a knife edge. Anyway, I can't tell the difference personally.

I don't think that the "average" pilot that goes to the field with thier average sport plane will really be able to tell the difference on any given flight unless that pilot is really focused on that issue alone.

Just MY opinion.

Ummm, adding one other thing..........personally I think the recommendation to fly 6 volt over 4.8 is perhaps a bit prudent only for the sake of not having to worry about it. I don't hesitate to fly 4.8 since I keep to a regular regime of monitoring my battery. If someone doesn't, then it may be best to switch to 6 volts...............MY opinion again.

Gray Beard

My Feedback: (-1)

Most people don't notice the difference in speed or power, some do. I still have some 4.8 volt packs and I use them but when I buy new I always buy 6 volt these days. I'm also still on 72 but just bought a Hitec Module for my Futaba 9-C, just haven't gotten any RXs yet. I use digital servos for the most part but even there I mix and match. All and every brown out I have seen, and that's a lot of them over the last 4 years was with JR/Spectrum. Pretty much always a battery problem but not always. The reason for that could be there are only two people I know using the Futaba 2,4?? One of them is using a JR module in his Futaba 9-C and JR RXs so I guess that would only really be one Futaba 2.4? Better safe then sorry so 6 volt is just a good idea and why bother chancing it for the price difference. Just for the record, I'm a Futaba person but I see the one Futaba and 30 JR/Spectrums on any given day so when there is a problem no mater what it's usually going to be the number one brand radio. Too bad Futaba didn't come out with there really good system first and learn how to market!!

rcjetflyer0718-RCU

My Feedback: (1)

If you use a 4 cell pack and lose a cell you lose the plane, but if you use a 5 cell pack and lose a cell you still have the plane. When I first started flying in the early 80s most of the planes I crashed was due to losing a cell or bad switch, now when I use a 5 cell I don,t lose planes due to batteries. Before each flight I check the battery, yeah maybe excessive but you can never know when a battery will fail.

tony0707

HI YOU will not feel any difference on the TX sticks IF YOUR servos are rated for 6.0V and you use 6.0 V packs you will have an increase in servo speed and servo torque in the airframe A VERY GOOD THING i personally use only NICADS on my TX and RX (old school ) they are 1000 OR 1300 MAH packs and after 20 years of flying experience- feel they are still the best value and performance for 40 to quarter scale aircraft i fly on FUTABA 72 Mhz ( if it ain't broke don't fix it ) if a battery goes bad in your RX pack you may still fly the plane to safety that speaks for itself
if you go to -AIRPLANES- on the home page here then to -BATTERIES AND CHARGERS you will see my ad- i build 1000 and 1300 MAH 6.0 V packs for the hobby at the best prices you will see anyplace !!- LIPOS are dangerous ! loose a battery on a 123 pack (you only have two )you are in- ! NIMH are sensative to slight over charges-not as good with vibration have less current -with more current drop than NICADS the weight saved is not an issue with 40 to quarter scale size aircraft- DO ENJOY- BEST REGARDS TONY

SushiSeeker

Awesone!!!
My first twin (15 years ago when I got in the hobby for the first time) was a twin telemaster. I took my trainer and made it a twin. Looks like you went on steroids and made quads and 6-packs.

bigedmustafa

My Feedback: (2)

I have a number of sport planes that I fly with 4.8V 600mAh to 1000mAh NiCd receiver packs. I use these batteries with Futaba R127DF, Hitec Supreme IIs, and GWS RD8SL 72Mhz dual conversion 7 or 8 channel FM receivers, a Futaba R138DP 72Mhz PCM receiver, and a number of Airtronics 92824 2.4Ghz FHSS receivers.

Ironically, I've been buying more and more 6v NiMH receiver packs in the 1200 to 1600mAh range lately. I don't appear to derive any performance advantage from these higher voltage receiver batteries, they're simply available for less than the cost of 4.8v 600Mah NiCd packs now.

I use a variety of Futaba S3003, S3004, JR ST-47, Hitec HS-311, HS-425BB, and Airtronics 94102Z servos in my sport planes, and none of these servos gain a significant increase in performance from the voltage boost.

Please be aware that NiMH batteries need to be slow charged and shaped when they are new. You can't just quick charge NiMH batteries and go fly; if you try that with receiver packs, the result will be disaster.

TimBle

Agreed, 4.8V NiCAD packs are starting to be pricey.

Also 4.8V packs are still in wide spread use, including all 2.4Ghz systems. Is 6V safer? No it's not.

I've skipped the 6VNiMH thing and gone striaght to 6.6V LiFePO4. Not for the voltage but for the lighter weight and smaller footprint, ability to be ultra fast charged at up to 4C on a compatible charger.

I do not subscribe to the theory that if you loose a cell on a 5cell pack you can still save the plane. Those cells are wired in series, If you loose the last cell in series then you have no battery pack so I don't consider that to be a safety net. If it was wired in parallel then I would subscribe to the theory. Loosing a cell is bad news in any battery  pack. The reason is the other cells try to pump harder to push through the now bigger internal resistance. They still deliver the required voltage but  the current draw across them isgreater. You still won't know you have a problem till the problem is in your face, out of your hands. You only know you have a problem if the capacity has dropped quickly while the plane is still on the ground and often that does not happen because when you check, voltage is stillhigh but drops off once you're up inthe air and you have the servo's working.

Brown out issues IMO are related mostly to operator error. Spektrum may get mentioned more than other systems but it also works just fine for most people I fly with. Sure there are better systems, especially when flying bigger planes but I have serious doubts that the technology is the problem.

Battery packs gets damaged very easily due to;,
1) the charger having a problem
2) the work bench (dropped)
3) crashes (falls under dropped)
4) Domestic maintenenace engineer unplugs the charger with the battery still plugged in for a few hours then plugs it back in and you think its been on charge for 15hrs when 5 is the reality....
5) your packs being used in barbie's convertible when the neighbours kids come over to play...
6) many other reasons.

Only cycling during charging operations on a high quality computerised charger will help you indentify problems with battery packs.

6V is not a cure for brown out. Care and maintenance is.

CGRetired

My Feedback: (1)

Absolutely. And my point is that many fly when they really should not. I've read, here on RCU, of pilots that measure voltage of their pack after, say 4 flights, think they can get "one more flight" out of it, then go up. Often the end result is a destroyed aircraft. It won't go to fail-safe because the battery is to low to allow the receiver to function that way. So, if it dies in a turn or roll, well, guess what..

This falls into the came category (different subject, I know, but same results) of the pilot that is making a lousy approach, and then decides to land even though it is not lined up properly or is to long, or.. to short... and ends up pushing it to the point where it is lands in a cartwheel or in the trees.. whatever... when he/she should have gone around and tried again.

It comes down to pilot error.

We've advocated use of 6 volt packs to try to get away from this low voltage brown-out issue, but nothing will work if the pilot wants to push it to the point where the battery, no matter how many cells, is just plain drained. And, of course, as you said, he/she should have started out with a good, fully-charged, well maintained battery pack.

CGr.

jib

4.8 is fine with Spektrum. I still have at least 6 packs still in use. Just be sure, as with any battery pack, that they are in good shape.

I will buy 6.0 volt when I replace them, but there is no reason to stop using good 4.8's.

Jack

StevL

Pros and cons of 4.8 vs. 6 volt packs (either NiCd or NiMh), you decide what is right for you. There are of course many other options.

4.8v pros
lighter (one cell less weight)

4.8v cons
slower servos
servos have less torque
if the pack drops a cell there is no redundancy

6v pros
faster servos
servos have more torque
if the pack drops a cell there will be redundancy provided it's not from a broken solder/weld joint and depending on which cell (I had one pack lose a cell 4 years ago and the 5 cell pack saved my plane...believe it or not)

6v cons
heavier (one cell more weight)

Ever notice pilots flying giant scale, turbines, complicated models almost always opt for redundancy. Why not do the same for smaller models?

Cheers,
Steve

TimBle

Luchnia

My Feedback: (21)

Not sure how this affects other RC planes and flyers, but I can certainly share my experiences. I recently switched three planes to 5C 6V 2000 NIMH packs (GP Rev 70, Rev 50, and H9 Pulse XT 40) and I was amazed! I normally used the 4C 4.8 V packs. It is a huge difference and noticeable in all three planes.

I can fly my planes all day and the planes are quicker responding and the batteries hold up much better to the loads. I never could imagine this would make that much of a difference. The other day I flew about a half gallon of fuel through my Pulse XT and checked the pack later on in the day and the pack was around 6.5-6.8! I usually get to the field and flying around 7:30 AM and hang out until around 1-2 or even much later. [8D]

TimBle

how old were your 4.8V packs?

Luchnia

My Feedback: (21)

My 4.8 V packs are fairly new. I was a bit cautious when I started flying and bought new 4.8 packs to replace any old NI CAD packs I had (last year). I have only been flying RC since last May. The packs are the ones Tower sells. I think they are called Hydrimax. They are green-blue batteries. They really seem to be good packs for the money.

I am sure I can get the cheaper "import" packs but these Hydrimax packs certainly do a great job (so-far). I often wonder how long you should use a battery pack. One of the guys at our field said he had four years on some of his packs! I am thinking that a more frequent replacement schedule would be better and not chance a crashed plane over a 20 dollar battery pack....just my two cents.

I am finishing up a new Hangar 9 Twist 40 V2 and I am going to put one of my 4C 4.8V packs in and see how they compare to the 5C 6V packs. Should be interesing.

StevL

Just to give you a brief history of what happened.... and I'm no electronic expert!!

After a flight I checked my battery voltage under a 1 amp load, my battery pack checked 5.1 volts.... way down for a six volt pack. I tried to charge the pack and kept getting errors (Bantam BC6) and it would not charge. Figuring the pack was gone I took the battery out and the shrink wrap off while at the field. We checked each cell with a volt meter and one cell had no voltage (well a couple tenths of one volt).

I then trashed the pack.... I have no idea how, what , or why but it happened. Even in *most pack failures* if the 5th cell will not help, I would still rather have the one in a million chance that it may.

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Off Subject
All my larger planes I fly dual li-ion packs and have never had a battery issue (knocking on wood). I like the idea of the A123 I just don't like the idea I can't load test them.
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Steve

hulio516

What charger you are using to charge your new 6v 2000 NIMH batteries?

I'd like to know,

hulio