DGUY

My Feedback: (9)

I am kind of out of the loop but is there a way to run... say a 11.1v LIPO in my JR 9303 transmitter and a 6.6v LIFE batt on the receiver?
thanks
Derrick

jester_s1

Quite a few people are doing exactly that, although I'm not aware of any of the manufacturers officially saying it's ok to do so. A better choice for your transmitter is a 3 LiFe at 9.9 volts. It will practically match the voltage of a fully charged NiCd and can't do any harm at all. The LiFe receiver pack also is very close to the same voltage as a 6 cell NiCd hot off the charger. There has been some debate as to whether the 6v rating of most servos means 6 actual volts or acceptable for a 6v NiCd. If it's the latter (which makes sense to me unless the manual specifically states otherwise), there is only a .2 volt difference between the LiFe and the NiCd when fully charged so there's no worry.

BarracudaHockey

My Feedback: (11)

I dunno who's debating the servo voltage thing. A 4.8v rating means a 4 cell pack, a 6v rating means a 5 cell.

Unless you have some old, or special use (some heli tail rotor servos) most of the rest of the servos run well on a 2 cell LiFe (A123) pack.

For the record I prefer true A123 systems cells over the other brands of LiFe soft packs that are running around, I get my reciever packs from www.wrongwayrc.com

DGUY

My Feedback: (9)

The servos that I am using are the JR D 821's. I am pretty sure that is what the number on them are, and standard jr on the throttle.
Derrick

tacx

My Feedback: (1)

The only issue with using a lipo in your TX is charging. Lipos are taken out of a plane for charging because they are more unstable than the other chemistries. No one wants their plane to go up in flames because of a bad or improperly charged lipo.

I would think the same would apply to your TX. Taking it out every time you want to charge it could be a pain.

As far as the Life batteries. I have all life batteries in all my planes with an assortment of different servos and have never had a problem. You will love them.

BarracudaHockey

My Feedback: (11)

The DS821's will work on A123 no issue

AA5BY

Will I love dealing with the balancing leads?

jester_s1

I've gone to LiFe receiver packs and transmitter packs. It takes about 5 seconds to plug in the balancing lead. So I suppose if your time is really, really valuable then they are a problem. Of course, if your time is that valuable you should be playing with toy airplanes! The only aggravation with the leads for Rx packs is having to get your charger close enough to plug the lead into the balancing board.

tacx

My Feedback: (1)

Jester,
This true, but that is the same issue with NImh that are left in the plane. For years we have been bringing our chargers to the plane. I personally have no problem with doing this. Infact, I just finished a Sig Hog Bipe that I do not disassemble to take to the field. So I mounted the balance jack into the fuse right below my charge jack. Works out great.

tacx

My Feedback: (1)

AA5by,

Not sure what you mean. If you are using a lipo in your TX, I'm sure you are removing it to charge. If thats the case then why would plugging in the balance plug be a problem? If you are charging it inside your TX your taking a chance.

jester_s1

What I mean was that since most balance board leads are pretty short compared to charging leads, it's a little bit of a hassle to get the balance lead plugged in. On my charger my 2 pronged charge lead is about 3 feet long, but my balance board connector is only about 6 inches.

JohnBuckner

My Feedback: (1)

Something really rather important here when anyone is contemplating the use of lipo's in a transmitter, I am only addressing lipos and not any other chemistry as well as only when used in transmitters.

In addition to the inability to charge the battery when installed in the transmitter due to the danger that tacx addressed (by the way a lovely Hog Bipe tacx) one must remember in most cases the first time you leave the tranny switch on inadvertantly (something I have certainly been guilty of many times) you likely will have destroyed the battery.

Have had several locals do exactly this after having to listen to them brag about only having to charge in x number of days. Sure enough they were soon sheepishly ordering new batterys.

Agine am only talking about lipo use in transmitters.

I recently completed a long cross country flight down the Colorado river and since I was using the low voltage Aurura 9, I choose to velcro a 3000mah six cell Nimh to the back externally and use no internal battery at all.

John

AA5BY

Ok... describing my situation. Most of my planes are set up for three batteries with typically two 5 cell 1100-1400 mah and one 4 cell ignition battery also of 1100 mah. All have a combo switch/charge port. My chargers/cyclers/float chargers are wall mounted with 4' leads that allow retrieving a 20-35cc size plane from the garage to the model shop (adjacent to the garage) to the bench just inside the door where charging takes place. Only one plane is taken to the field on a given day and it usually gets flown twice and sometimes three times. If it has been a while since that plane has been flown, it gets hit with a discharge cycle and full charge level for a sixteen hour charge at which point the charger autos to trickle. If the plane has been flown recently and the batteries are not suspect, I don't discharge when hooking up and simply let them trickle charge, which they seem to do fine with my chargers. I always hook up the day before I'm going to fly a plane... unless its my goto plane which stays on trickle charge and is ready to go anytime with a full charge.

I don't do any charging at the field.

If changing to LiFe, I'm expecting I'd have to dig inside the plane to hook up the balancing leads and there would be three sets of them, right? Plus there would be some kind of regulator on the ignitions that don't do more than 4.8 volts, right? I think what I'm getting at is that I've no doubt LiFe batteries are a good way to go for many but I'm not thinking they are a good way to go for my situation as I'd want to mount a x4 charger on the wall with charging and balancing leads all 4' long.

Last... if I were dissatisfied with NiCads, I'd have more impetus to deal with change. I'm not. I've never lost a plane due to a NiCad battery problem and they don't cramp my flying in any way and I find them simple to manage.

AA5BY

Good point John... I've left my transmitter on about three times in the last ten years. And, with not getting younger, could I expect to double that in the next ten years?

Is LiFe technology similarly destructive when totally discharging the battery?

DGUY

My Feedback: (9)

What kind of length of usage would you get using these batteries. Would they last the whole weekend of a fly in so you would not have to charge during the festivities.

scale only 4 me

My Feedback: (158)

Well that all depends on the plane as far as the a123s go

I use one in my 120 size ta152, I could easily get 10-12 flights,, I use 2 in my 50cc and up size aerobatic planes,, typically 2-3 flights then charge is the norm.

For the 3s lipo in a TX,, Mine gets charged once a month weather it needs it or not.


p.s.
Personally I would not use Life9.9 packs in a TX,, they fall off too fast after they reach that 9.9 volts point. By the time your low voltage alarm is going off they have been tanking fast.