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Old Jan 27, 2013, 12:51 PM
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South Africa, GP, Centurion
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Why use Lipos in TX / Controllers

Hi Guys

What do I miss - everyone seems to go to Lipo's for their TX/Controllers.

I have been using 4 x AA (2450mAh NiMh) and they have double the power capacity (Wh) than a 7.4V 2s 800mAh lipo that I can fit in that same space.

Even if the Controller can take a 11V / 3S lipo the max physical size drops the mAh capacity and thus the Wh, to way less than 4 x AA

Any ideas?
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Old Jan 27, 2013, 12:55 PM
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So. Cal.
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They don't know any better.

For transmitters that require 8 AA cells, a lipoly can be cheaper and will also be lighter. For me, they're not worth the hassle and I use AA Eneloops in all of my transmitters as I find them far less risky and more convenient.

Mark
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Old Jan 27, 2013, 01:14 PM
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Letchworth, Great Britain (UK)
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Originally Posted by mrforsyth View Post
... For transmitters that require 8 AA cells, a lipoly can be cheaper and will also be lighter. For me, they're not worth the hassle and I use AA Eneloops in all of my transmitters as I find them far less risky and more convenient.

Mark
+1. I prefer to keep it simple, and I've had no problem with the stock 8-cell NiMh packs, varying between 800 and 1200mAh, supplied with my Futaba sets. This weekend I bought a 2000mAh Eneloop pack to replace a pack that's beginning to lose capacity. No fussy battery management -- I just put it on slow charge the night before I'm going flying.
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Old Jan 27, 2013, 01:17 PM
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South Africa, GP, Centurion
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Thanks Mark

I also have no intentions to move, my TX uses 4 x AA driving, (I guess) 3.3V electronics, so there is no reason to go to Lipos or higher supply voltage to reduce losses as one would do on the heli side.

Guess they need to remember Ohm's and the other power laws .
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Old Jan 27, 2013, 03:57 PM
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United States, CA, Bear Valley Springs
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Originally Posted by randmental View Post
Guess they need to remember Ohm's and the other power laws .
Quote:
They don't know any better.
And there ya have it.

mw
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Old Jan 27, 2013, 04:06 PM
rrg
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USA, KY, Edgewood
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Seems like we are all in agreement.......
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Old Jan 27, 2013, 04:24 PM
PGR
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United States, CA, Costa Mesa
Joined Jun 2004
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Originally Posted by rrg View Post
Seems like we are all in agreement.......
Only because the LiPo proponents haven't shown up yet.

They'll come, though. They always do.

Pete
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Old Jan 27, 2013, 04:37 PM
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United States, CA, Brentwood
Joined Jun 2012
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Lost a plane from AA nimh batteries in the spring holder. A soldered pack no problem, but way to many weak connections on a spring type holder with normal cells. I've also had zero problems with a low discharge lipo pack, and being a 2650, the charge holds for a long time. Also had zero problems with my iPad with lipos, iPod, and so on. Carbureted cars were all the rage 30 years ago to😜
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Old Jan 27, 2013, 04:40 PM
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So. Cal.
Joined Oct 2004
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Interesting. I've been using Radio Shack AA holders in all of my transmitters for the last 7 years and have yet to experience even the slightest glitch.

Mark
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Old Jan 27, 2013, 07:31 PM
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I'm using the default 4.8v 2000mAh NiMH that came with my transmitter (DX8), however, the manufacturer also offers a 7.4V 4000mAh LiPo as an option. The optional LiPo is slightly larger, however the transmitter was designed for it, and comes with two differently shaped foam spacers depending on which battery you use.

So, one reason that some people may be going with lipos is that the numbers don't always work out the way they do in the original post.
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Old Jan 27, 2013, 08:05 PM
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The Northeast Kingdom, Vermont
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Originally Posted by PGR View Post
Only because the LiPo proponents haven't shown up yet.

They'll come, though. They always do.

Pete
OK, I wouldn't want to disappoint anyone now, so here goes

When folks ask how can they put a Lipo in their tranny that takes loose AA cells, I say fuggedaboudit, just get some Eneloopers
Any use of a lipo, where one has to do some creative "bashing" to use a Lipo in their radio is not a good idea in my book. I'm also not that comfortable with using a fully charged 3S in place of an 8 cell Nixx that only charges to about 11.4V, though two diodes in the battery lead will fix that and also make the low voltage warning for the stock battery closer to what it should be for the 3S Lipo.

Many of our newer transmitters are designed with Lipos in mind, at least as an option. I'm running a 2S low C rated Tx Lipo made specifically for the Futaba 12FG and 8FG in my 8FG. Perfect fit, easy access to the balance tap and I can set the low voltage warning to where I want it, I set it a little higher than Futabas recommended setting for Lipo. With the Lipo, I slide the battery out of the bottom of the radio to charge it, usually while having lunch at the field.

At my club, there are more and more E-power only guys flying with Lipos, so you see more and more Lipos in the transmitters.

I guess it all depends
Pete
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Old Jan 28, 2013, 02:54 PM
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Victorville, CA
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I just starting using these LiFe packs in my older DX7's.
http://www.hobbyking.com/hobbyking/s...ter_pack_.html
They have worked well so far but have to be charged out of the Tx. I miss being able to just plug in the wall wart the night before and have it charge along with all my planes in the trailer. My new Tx is a DX8 and I have this pack in it.
http://www.hobbyking.com/hobbyking/s...ter_Pack_.html
That will charge on it's wall wart over night.
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Old Jan 28, 2013, 03:00 PM
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http://www.rcgroups.com/forums/showthread.php?t=821683
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Old Jan 28, 2013, 03:07 PM
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United States, NC, Garner
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Quote:
Originally Posted by abenn View Post
+1. I prefer to keep it simple, and I've had no problem with the stock 8-cell NiMh packs, varying between 800 and 1200mAh, supplied with my Futaba sets. This weekend I bought a 2000mAh Eneloop pack to replace a pack that's beginning to lose capacity. No fussy battery management -- I just put it on slow charge the night before I'm going flying.
...and that's the EXACT reason why I went away from NiMH packs in my Futaba 10CHG and went with a 9.9v 2200 mAh LiFePO4 pack. No wall-wart chargers to dig out from who-knows-where, no having to remember to charge the night before, no NiMH cells to cycle. I get about 10 hours out of the 2200 mAh pack and if I forget to charge it, I simply charge it at the field with my existing charging infrastructure in minutes and I'm good to go.

I know the OP said LiPo, but I use LiFePO4 so I don't over-zap my expensive radio. Nothing wrong with Eneloops, but I use what works for me. YMMV.
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Old Jan 28, 2013, 04:12 PM
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Willmar, Minnesota, United States
Joined Sep 2004
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yup, I use Lipo's in my Transmitters that were designed to use them at least optionally.
I've never liked needing to remember to charge my tx the night before... but also was never comfortable with 'fast charging' Nicad/ NiMH packs..
my personal answer:
I use Lipo's only in transmitters designed specifically for them.
when I need to charge them, I've got the equipment to properly do so even at the field.
(I've also got a couple older JR radios that were not designed for Lipo's... I don't use lipos in them.)
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